⑦ Maintenance and Monitoring
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Maintenance #
https://docs.ceph.com/en/latest/rados/operations/health-checks/ https://sabaini.at/pages/ceph-cheatsheet.html #
Health checks #
Overview #
There is a finite set of possible health messages that a Ceph cluster can
raise – these are defined as health checks which have unique identifiers.
The identifier is a terse pseudo-human-readable (i.e. like a variable name)
string. It is intended to enable tools (such as UIs) to make sense of
health checks, and present them in a way that reflects their meaning.
This page lists the health checks that are raised by the monitor and manager
daemons. In addition to these, you may also see health checks that originate
from MDS daemons (see :ref:cephfs-health-messages), and health checks
that are defined by ceph-mgr python modules.
Definitions #
Monitor #
DAEMON_OLD_VERSION
Warn if old version(s) of Ceph are running on any daemons. It will generate a health error if multiple versions are detected. This condition must exist for over mon_warn_older_version_delay (set to 1 week by default) in order for the health condition to be triggered. This allows most upgrades to proceed without falsely seeing the warning. If upgrade is paused for an extended time period, health mute can be used like this “ceph health mute DAEMON_OLD_VERSION –sticky”. In this case after upgrade has finished use “ceph health unmute DAEMON_OLD_VERSION”. MON_DOWN
One or more monitor daemons is currently down. The cluster requires a majority (more than 1/2) of the monitors in order to function. When one or more monitors are down, clients may have a harder time forming their initial connection to the cluster as they may need to try more addresses before they reach an operating monitor. The down monitor daemon should generally be restarted as soon as possible to reduce the risk of a subsequent monitor failure leading to a service outage. MON_CLOCK_SKEW
The clocks on the hosts running the ceph-mon monitor daemons are not
sufficiently well synchronized. This health alert is raised if the
cluster detects a clock skew greater than mon_clock_drift_allowed.
This is best resolved by synchronizing the clocks using a tool like
ntpd or chrony.
If it is impractical to keep the clocks closely synchronized, the
mon_clock_drift_allowed threshold can also be increased, but this
value must stay significantly below the mon_lease interval in
order for monitor cluster to function properly.
MON_MSGR2_NOT_ENABLED
The :confval:ms_bind_msgr2 option is enabled but one or more monitors is
not configured to bind to a v2 port in the cluster’s monmap. This
means that features specific to the msgr2 protocol (e.g., encryption)
are not available on some or all connections.
In most cases this can be corrected by issuing the command:
.. prompt:: bash $
ceph mon enable-msgr2
That command will change any monitor configured for the old default
port 6789 to continue to listen for v1 connections on 6789 and also
listen for v2 connections on the new default 3300 port.
If a monitor is configured to listen for v1 connections on a non-standard port (not 6789), then the monmap will need to be modified manually.
MON_DISK_LOW
One or more monitors is low on disk space. This alert triggers if the
available space on the file system storing the monitor database
(normally /var/lib/ceph/mon), as a percentage, drops below
mon_data_avail_warn (default: 30%).
This may indicate that some other process or user on the system is
filling up the same file system used by the monitor. It may also
indicate that the monitors database is large (see MON_DISK_BIG
below).
If space cannot be freed, the monitor’s data directory may need to be
moved to another storage device or file system (while the monitor
daemon is not running, of course).
MON_DISK_CRIT
One or more monitors is critically low on disk space. This alert
triggers if the available space on the file system storing the monitor
database (normally /var/lib/ceph/mon), as a percentage, drops
below mon_data_avail_crit (default: 5%). See MON_DISK_LOW, above.
MON_DISK_BIG
The database size for one or more monitors is very large. This alert
triggers if the size of the monitor’s database is larger than
mon_data_size_warn (default: 15 GiB).
A large database is unusual, but may not necessarily indicate a
problem. Monitor databases may grow in size when there are placement
groups that have not reached an active+clean state in a long time.
This may also indicate that the monitor’s database is not properly
compacting, which has been observed with some older versions of
leveldb and rocksdb. Forcing a compaction with ceph daemon mon.<id> compact may shrink the on-disk size.
This warning may also indicate that the monitor has a bug that is
preventing it from pruning the cluster metadata it stores. If the
problem persists, please report a bug.
The warning threshold may be adjusted with:
.. prompt:: bash $
ceph config set global mon_data_size_warn
One or more clients or daemons are connected to the cluster that are
not securely reclaiming their global_id (a unique number identifying
each entity in the cluster) when reconnecting to a monitor. The
client is being permitted to connect anyway because the
auth_allow_insecure_global_id_reclaim option is set to true (which may
be necessary until all ceph clients have been upgraded), and the
auth_expose_insecure_global_id_reclaim option set to true (which
allows monitors to detect clients with insecure reclaim early by forcing them to
reconnect right after they first authenticate).
You can identify which client(s) are using unpatched ceph client code with:
.. prompt:: bash $
ceph health detail
Clients’ global_id reclaim behavior can also seen in the
global_id_status field in the dump of clients connected to an
individual monitor (reclaim_insecure means the client is
unpatched and is contributing to this health alert):
.. prompt:: bash $
ceph tell mon.* sessions
We strongly recommend that all clients in the system are upgraded to a
newer version of Ceph that correctly reclaims global_id values. Once
all clients have been updated, you can stop allowing insecure reconnections
with:
.. prompt:: bash $
ceph config set mon auth_allow_insecure_global_id_reclaim false
If it is impractical to upgrade all clients immediately, you can silence
this warning temporarily with:
.. prompt:: bash $
ceph health mute AUTH_INSECURE_GLOBAL_ID_RECLAIM 1w # 1 week
Although we do NOT recommend doing so, you can also disable this warning
indefinitely with:
.. prompt:: bash $
ceph config set mon mon_warn_on_insecure_global_id_reclaim false
AUTH_INSECURE_GLOBAL_ID_RECLAIM_ALLOWED
Ceph is currently configured to allow clients to reconnect to monitors using
an insecure process to reclaim their previous global_id because the setting
auth_allow_insecure_global_id_reclaim is set to true. It may be necessary to
leave this setting enabled while existing Ceph clients are upgraded to newer
versions of Ceph that correctly and securely reclaim their global_id.
If the AUTH_INSECURE_GLOBAL_ID_RECLAIM health alert has not also been raised and
the auth_expose_insecure_global_id_reclaim setting has not been disabled (it is
on by default), then there are currently no clients connected that need to be
upgraded, and it is safe to disallow insecure global_id reclaim with:
.. prompt:: bash $
ceph config set mon auth_allow_insecure_global_id_reclaim false
If there are still clients that need to be upgraded, then this alert can be
silenced temporarily with:
.. prompt:: bash $
ceph health mute AUTH_INSECURE_GLOBAL_ID_RECLAIM_ALLOWED 1w # 1 week
Although we do NOT recommend doing so, you can also disable this warning indefinitely
with:
.. prompt:: bash $
ceph config set mon mon_warn_on_insecure_global_id_reclaim_allowed false
Manager #
MGR_DOWN
All manager daemons are currently down. The cluster should normally
have at least one running manager (ceph-mgr) daemon. If no
manager daemon is running, the cluster’s ability to monitor itself will
be compromised, and parts of the management API will become
unavailable (for example, the dashboard will not work, and most CLI
commands that report metrics or runtime state will block). However,
the cluster will still be able to perform all IO operations and
recover from failures.
The down manager daemon should generally be restarted as soon as
possible to ensure that the cluster can be monitored (e.g., so that
the ceph -s information is up to date, and/or metrics can be
scraped by Prometheus).
MGR_MODULE_DEPENDENCY
An enabled manager module is failing its dependency check. This health check
should come with an explanatory message from the module about the problem.
For example, a module might report that a required package is not installed:
install the required package and restart your manager daemons.
This health check is only applied to enabled modules. If a module is
not enabled, you can see whether it is reporting dependency issues in
the output of ceph module ls.
MGR_MODULE_ERROR
A manager module has experienced an unexpected error. Typically,
this means an unhandled exception was raised from the module’s serve
function. The human readable description of the error may be obscurely
worded if the exception did not provide a useful description of itself.
This health check may indicate a bug: please open a Ceph bug report if you
think you have encountered a bug.
If you believe the error is transient, you may restart your manager
daemon(s), or use ceph mgr fail on the active daemon to prompt
a failover to another daemon.
OSDs #
OSD_DOWN
One or more OSDs are marked down. The ceph-osd daemon may have been
stopped, or peer OSDs may be unable to reach the OSD over the network.
Common causes include a stopped or crashed daemon, a down host, or a
network outage.
Verify the host is healthy, the daemon is started, and network is
functioning. If the daemon has crashed, the daemon log file
(/var/log/ceph/ceph-osd.*) may contain debugging information.
OSD_
(e.g. OSD_HOST_DOWN, OSD_ROOT_DOWN) All the OSDs within a particular CRUSH subtree are marked down, for example all OSDs on a host. OSD_ORPHAN
An OSD is referenced in the CRUSH map hierarchy but does not exist.
The OSD can be removed from the CRUSH hierarchy with:
.. prompt:: bash $
ceph osd crush rm osd.
The utilization thresholds for nearfull, backfillfull, full,
and/or failsafe_full are not ascending. In particular, we expect
nearfull < backfillfull, backfillfull < full, and full < failsafe_full.
The thresholds can be adjusted with:
.. prompt:: bash $
ceph osd set-nearfull-ratio
One or more OSDs has exceeded the full threshold and is preventing
the cluster from servicing writes.
Utilization by pool can be checked with:
.. prompt:: bash $
ceph df
The currently defined full ratio can be seen with:
.. prompt:: bash $
ceph osd dump | grep full_ratio
A short-term workaround to restore write availability is to raise the full
threshold by a small amount:
.. prompt:: bash $
ceph osd set-full-ratio
One or more OSDs has exceeded the backfillfull threshold or would exceed
when the currently mapped backfills finish, which will prevent data from being
allowed to rebalance to this device. This is an early warning that rebalancing
may not be able to complete and that the cluster is approaching full.
Utilization by pool can be checked with:
.. prompt:: bash $
ceph df
OSD_NEARFULL
One or more OSDs has exceeded the nearfull threshold. This is an early
warning that the cluster is approaching full.
Utilization by pool can be checked with:
.. prompt:: bash $
ceph df
OSDMAP_FLAGS
One or more cluster flags of interest has been set. These flags include:
- full - the cluster is flagged as full and cannot serve writes
- pauserd, pausewr - paused reads or writes
- noup - OSDs are not allowed to start
- nodown - OSD failure reports are being ignored, such that the
monitors will not mark OSDs
down - noin - OSDs that were previously marked
outwill not be marked backinwhen they start - noout - down OSDs will not automatically be marked out after the configured interval
- nobackfill, norecover, norebalance - recovery or data rebalancing is suspended
- noscrub, nodeep_scrub - scrubbing is disabled
- notieragent - cache tiering activity is suspended
With the exception of full, these flags can be set or cleared with:
.. prompt:: bash $
ceph osd set
ceph osd unset OSD_FLAGS
One or more OSDs or CRUSH {nodes,device classes} has a flag of interest set. These flags include:
- noup: these OSDs are not allowed to start
- nodown: failure reports for these OSDs will be ignored
- noin: if these OSDs were previously marked
outautomatically after a failure, they will not be marked in when they start - noout: if these OSDs are down they will not automatically be marked
outafter the configured interval These flags can be set and cleared in batch with: .. prompt:: bash $ ceph osd set-groupceph osd unset-group For example: .. prompt:: bash $ ceph osd set-group noup,noout osd.0 osd.1 ceph osd unset-group noup,noout osd.0 osd.1 ceph osd set-group noup,noout host-foo ceph osd unset-group noup,noout host-foo ceph osd set-group noup,noout class-hdd ceph osd unset-group noup,noout class-hdd OLD_CRUSH_TUNABLES
The CRUSH map is using very old settings and should be updated. The
oldest tunables that can be used (i.e., the oldest client version that
can connect to the cluster) without triggering this health warning is
determined by the mon_crush_min_required_version config option.
See :ref:crush-map-tunables for more information.
OLD_CRUSH_STRAW_CALC_VERSION
The CRUSH map is using an older, non-optimal method for calculating
intermediate weight values for straw buckets.
The CRUSH map should be updated to use the newer method
(straw_calc_version=1). See
:ref:crush-map-tunables for more information.
CACHE_POOL_NO_HIT_SET
One or more cache pools is not configured with a hit set to track
utilization, which will prevent the tiering agent from identifying
cold objects to flush and evict from the cache.
Hit sets can be configured on the cache pool with:
.. prompt:: bash $
ceph osd pool set
No pre-Luminous v12.y.z OSDs are running but the sortbitwise flag has not
been set.
The sortbitwise flag must be set before OSDs running Luminous v12.y.z or newer
can start. You can safely set the flag with:
.. prompt:: bash $
ceph osd set sortbitwise
OSD_FILESTORE
The Filestore OSD back end has been deprecated; the BlueStore back end has been the default objectstore for quite some time. Warn if OSDs are running Filestore. The ‘mclock_scheduler’ is not supported for Filestore OSDs. Therefore, the default ‘osd_op_queue’ is set to ‘wpq’ for Filestore OSDs and is enforced even if the user attempts to change it. Filestore OSDs can be listed with: .. prompt:: bash $ ceph report | jq -c ‘.“osd_metadata” | .[] | select(.osd_objectstore | contains(“filestore”)) | {id, osd_objectstore}’ In order to upgrade to Reef or later releases, any Filestore OSDs must first be migrated to BlueStore. When upgrading a release prior to Reef to Reef or later: if it is not feasible to migrate Filestore OSDs to BlueStore immediately, you can silence this warning temporarily with: .. prompt:: bash $ ceph health mute OSD_FILESTORE Since this migration can take considerable time to complete, we recommend that you begin the process well in advance of an update to Reef or later releases. POOL_FULL
One or more pools has reached its quota and is no longer allowing writes.
Pool quotas and utilization can be seen with:
.. prompt:: bash $
ceph df detail
You can either raise the pool quota with:
.. prompt:: bash $
ceph osd pool set-quota
One or more OSDs that use the BlueStore backend have been allocated
db partitions (storage space for metadata, normally on a faster
device) but that space has filled, such that metadata has “spilled
over” onto the normal slow device. This isn’t necessarily an error
condition or even unexpected, but if the administrator’s expectation
was that all metadata would fit on the faster device, it indicates
that not enough space was provided.
This warning can be disabled on all OSDs with:
.. prompt:: bash $
ceph config set osd bluestore_warn_on_bluefs_spillover false
Alternatively, it can be disabled on a specific OSD with:
.. prompt:: bash $
ceph config set osd.123 bluestore_warn_on_bluefs_spillover false
To provide more metadata space, the OSD in question could be destroyed and
reprovisioned. This will involve data migration and recovery.
It may also be possible to expand the LVM logical volume backing the
db storage. If the underlying LV has been expanded, the OSD daemon
needs to be stopped and BlueFS informed of the device size change with:
.. prompt:: bash $
ceph-bluestore-tool bluefs-bdev-expand –path /var/lib/ceph/osd/ceph-$ID
BLUEFS_AVAILABLE_SPACE
To check how much space is free for BlueFS do:
.. prompt:: bash $
ceph daemon osd.123 bluestore bluefs available
This will output up to 3 values: BDEV_DB free, BDEV_SLOW free and
available_from_bluestore. BDEV_DB and BDEV_SLOW report amount of space that
has been acquired by BlueFS and is considered free. Value available_from_bluestore
denotes ability of BlueStore to relinquish more space to BlueFS.
It is normal that this value is different from amount of BlueStore free space, as
BlueFS allocation unit is typically larger than BlueStore allocation unit.
This means that only part of BlueStore free space will be acceptable for BlueFS.
BLUEFS_LOW_SPACE
If BlueFS is running low on available free space and there is little
available_from_bluestore one can consider reducing BlueFS allocation unit size.
To simulate available space when allocation unit is different do:
.. prompt:: bash $
ceph daemon osd.123 bluestore bluefs available
As BlueStore works free space on underlying storage will get fragmented.
This is normal and unavoidable but excessive fragmentation will cause slowdown.
To inspect BlueStore fragmentation one can do:
.. prompt:: bash $
ceph daemon osd.123 bluestore allocator score block
Score is given in [0-1] range.
[0.0 .. 0.4] tiny fragmentation
[0.4 .. 0.7] small, acceptable fragmentation
[0.7 .. 0.9] considerable, but safe fragmentation
[0.9 .. 1.0] severe fragmentation, may impact BlueFS ability to get space from BlueStore
If detailed report of free fragments is required do:
.. prompt:: bash $
ceph daemon osd.123 bluestore allocator dump block
In case when handling OSD process that is not running fragmentation can be
inspected with ceph-bluestore-tool.
Get fragmentation score:
.. prompt:: bash $
ceph-bluestore-tool –path /var/lib/ceph/osd/ceph-123 –allocator block free-score
And dump detailed free chunks:
.. prompt:: bash $
ceph-bluestore-tool –path /var/lib/ceph/osd/ceph-123 –allocator block free-dump
BLUESTORE_LEGACY_STATFS
In the Nautilus release, BlueStore tracks its internal usage
statistics on a per-pool granular basis, and one or more OSDs have
BlueStore volumes that were created prior to Nautilus. If all OSDs
are older than Nautilus, this just means that the per-pool metrics are
not available. However, if there is a mix of pre-Nautilus and
post-Nautilus OSDs, the cluster usage statistics reported by ceph df will not be accurate.
The old OSDs can be updated to use the new usage tracking scheme by stopping each OSD, running a repair operation, and the restarting it. For example, if osd.123 needed to be updated,:
.. prompt:: bash $
systemctl stop ceph-osd@123
ceph-bluestore-tool repair –path /var/lib/ceph/osd/ceph-123
systemctl start ceph-osd@123
This warning can be disabled with:
.. prompt:: bash $
ceph config set global bluestore_warn_on_legacy_statfs false
BLUESTORE_NO_PER_POOL_OMAP
Starting with the Octopus release, BlueStore tracks omap space utilization
by pool, and one or more OSDs have volumes that were created prior to
Octopus. If all OSDs are not running BlueStore with the new tracking
enabled, the cluster will report and approximate value for per-pool omap usage
based on the most recent deep-scrub.
The old OSDs can be updated to track by pool by stopping each OSD,
running a repair operation, and the restarting it. For example, if
osd.123 needed to be updated,:
.. prompt:: bash $
systemctl stop ceph-osd@123
ceph-bluestore-tool repair –path /var/lib/ceph/osd/ceph-123
systemctl start ceph-osd@123
This warning can be disabled with:
.. prompt:: bash $
ceph config set global bluestore_warn_on_no_per_pool_omap false
BLUESTORE_NO_PER_PG_OMAP
Starting with the Pacific release, BlueStore tracks omap space utilization
by PG, and one or more OSDs have volumes that were created prior to
Pacific. Per-PG omap enables faster PG removal when PGs migrate.
The older OSDs can be updated to track by PG by stopping each OSD,
running a repair operation, and the restarting it. For example, if
osd.123 needed to be updated,:
.. prompt:: bash $
systemctl stop ceph-osd@123
ceph-bluestore-tool repair –path /var/lib/ceph/osd/ceph-123
systemctl start ceph-osd@123
This warning can be disabled with:
.. prompt:: bash $
ceph config set global bluestore_warn_on_no_per_pg_omap false
BLUESTORE_DISK_SIZE_MISMATCH
One or more OSDs using BlueStore has an internal inconsistency between the size
of the physical device and the metadata tracking its size. This can lead to
the OSD crashing in the future.
The OSDs in question should be destroyed and reprovisioned. Care should be
taken to do this one OSD at a time, and in a way that doesn’t put any data at
risk. For example, if osd $N has the error:
.. prompt:: bash $
ceph osd out osd.$N
while ! ceph osd safe-to-destroy osd.$N ; do sleep 1m ; done
ceph osd destroy osd.$N
ceph-volume lvm zap /path/to/device
ceph-volume lvm create –osd-id $N –data /path/to/device
BLUESTORE_NO_COMPRESSION
One or more OSDs is unable to load a BlueStore compression plugin.
This can be caused by a broken installation, in which the ceph-osd
binary does not match the compression plugins, or a recent upgrade
that did not include a restart of the ceph-osd daemon.
Verify that the package(s) on the host running the OSD(s) in question
are correctly installed and that the OSD daemon(s) have been
restarted. If the problem persists, check the OSD log for any clues
as to the source of the problem.
BLUESTORE_SPURIOUS_READ_ERRORS
One or more OSDs using BlueStore detects spurious read errors at main device. BlueStore has recovered from these errors by retrying disk reads. Though this might show some issues with underlying hardware, I/O subsystem, etc. Which theoretically might cause permanent data corruption. Some observations on the root cause can be found at https://tracker.ceph.com/issues/22464 This alert doesn’t require immediate response but corresponding host might need additional attention, e.g. upgrading to the latest OS/kernel versions and H/W resource utilization monitoring. This warning can be disabled on all OSDs with: .. prompt:: bash $ ceph config set osd bluestore_warn_on_spurious_read_errors false Alternatively, it can be disabled on a specific OSD with: .. prompt:: bash $ ceph config set osd.123 bluestore_warn_on_spurious_read_errors false Device health #
DEVICE_HEALTH
One or more devices is expected to fail soon, where the warning
threshold is controlled by the mgr/devicehealth/warn_threshold
config option.
This warning only applies to OSDs that are currently marked “in”, so
the expected response to this failure is to mark the device “out” so
that data is migrated off of the device, and then to remove the
hardware from the system. Note that the marking out is normally done
automatically if mgr/devicehealth/self_heal is enabled based on
the mgr/devicehealth/mark_out_threshold.
Device health can be checked with:
.. prompt:: bash $
ceph device info
One or more devices is expected to fail soon and has been marked “out”
of the cluster based on mgr/devicehealth/mark_out_threshold, but it
is still participating in one more PGs. This may be because it was
only recently marked “out” and data is still migrating, or because data
cannot be migrated off for some reason (e.g., the cluster is nearly
full, or the CRUSH hierarchy is such that there isn’t another suitable
OSD to migrate the data too).
This message can be silenced by disabling the self heal behavior
(setting mgr/devicehealth/self_heal to false), by adjusting the
mgr/devicehealth/mark_out_threshold, or by addressing what is
preventing data from being migrated off of the ailing device.
DEVICE_HEALTH_TOOMANY
Too many devices is expected to fail soon and the
mgr/devicehealth/self_heal behavior is enabled, such that marking
out all of the ailing devices would exceed the clusters
mon_osd_min_in_ratio ratio that prevents too many OSDs from being
automatically marked “out”.
This generally indicates that too many devices in your cluster are
expected to fail soon and you should take action to add newer
(healthier) devices before too many devices fail and data is lost.
The health message can also be silenced by adjusting parameters like
mon_osd_min_in_ratio or mgr/devicehealth/mark_out_threshold,
but be warned that this will increase the likelihood of unrecoverable
data loss in the cluster.
Data health (pools & placement groups) #
PG_AVAILABILITY
Data availability is reduced, meaning that the cluster is unable to
service potential read or write requests for some data in the cluster.
Specifically, one or more PGs is in a state that does not allow IO
requests to be serviced. Problematic PG states include peering,
stale, incomplete, and the lack of active (if those conditions do not clear
quickly).
Detailed information about which PGs are affected is available from:
.. prompt:: bash $
ceph health detail
In most cases the root cause is that one or more OSDs is currently
down; see the discussion for OSD_DOWN above.
The state of specific problematic PGs can be queried with:
.. prompt:: bash $
ceph tell
Data redundancy is reduced for some data, meaning the cluster does not have the desired number of replicas for all data (for replicated pools) or erasure code fragments (for erasure coded pools). Specifically, one or more PGs:
- has the degraded or undersized flag set, meaning there are not enough instances of that placement group in the cluster;
- has not had the clean flag set for some time.
Detailed information about which PGs are affected is available from:
.. prompt:: bash $
ceph health detail
In most cases the root cause is that one or more OSDs is currently
down; see the discussion for
OSD_DOWNabove. The state of specific problematic PGs can be queried with: .. prompt:: bash $ ceph tellquery PG_RECOVERY_FULL
Data redundancy may be reduced or at risk for some data due to a lack of free space in the cluster. Specifically, one or more PGs has the recovery_toofull flag set, meaning that the cluster is unable to migrate or recover data because one or more OSDs is above the full threshold. See the discussion for OSD_FULL above for steps to resolve this condition. PG_BACKFILL_FULL
Data redundancy may be reduced or at risk for some data due to a lack of free space in the cluster. Specifically, one or more PGs has the backfill_toofull flag set, meaning that the cluster is unable to migrate or recover data because one or more OSDs is above the backfillfull threshold. See the discussion for OSD_BACKFILLFULL above for steps to resolve this condition. PG_DAMAGED
Data scrubbing has discovered some problems with data consistency in the cluster. Specifically, one or more PGs has the inconsistent or snaptrim_error flag is set, indicating an earlier scrub operation found a problem, or that the repair flag is set, meaning a repair for such an inconsistency is currently in progress. See :doc:pg-repairfor more information. OSD_SCRUB_ERRORS
Recent OSD scrubs have uncovered inconsistencies. This error is generally paired with PG_DAMAGED (see above). See :doc:pg-repairfor more information. OSD_TOO_MANY_REPAIRS
When a read error occurs and another replica is available it is used to repair the error immediately, so that the client can get the object data. Scrub handles errors for data at rest. In order to identify possible failing disks that aren’t seeing scrub errors, a count of read repairs is maintained. If it exceeds a config value threshold mon_osd_warn_num_repaired default 10, this health warning is generated. LARGE_OMAP_OBJECTS
One or more pools contain large omap objects as determined byosd_deep_scrub_large_omap_object_key_threshold(threshold for number of keys to determine a large omap object) orosd_deep_scrub_large_omap_object_value_sum_threshold(the threshold for summed size (bytes) of all key values to determine a large omap object) or both. More information on the object name, key count, and size in bytes can be found by searching the cluster log for ‘Large omap object found’. Large omap objects can be caused by RGW bucket index objects that do not have automatic resharding enabled. Please see :ref:RGW Dynamic Bucket Index Resharding <rgw_dynamic_bucket_index_resharding>for more information on resharding. The thresholds can be adjusted with: .. prompt:: bash $ ceph config set osd osd_deep_scrub_large_omap_object_key_thresholdceph config set osd osd_deep_scrub_large_omap_object_value_sum_threshold CACHE_POOL_NEAR_FULL
A cache tier pool is nearly full. Full in this context is determined
by the target_max_bytes and target_max_objects properties on
the cache pool. Once the pool reaches the target threshold, write
requests to the pool may block while data is flushed and evicted
from the cache, a state that normally leads to very high latencies and
poor performance.
The cache pool target size can be adjusted with:
.. prompt:: bash $
ceph osd pool set
The number of PGs in use in the cluster is below the configurable
threshold of mon_pg_warn_min_per_osd PGs per OSD. This can lead
to suboptimal distribution and balance of data across the OSDs in
the cluster, and similarly reduce overall performance.
This may be an expected condition if data pools have not yet been
created.
The PG count for existing pools can be increased or new pools can be created.
Please refer to :ref:choosing-number-of-placement-groups for more
information.
POOL_PG_NUM_NOT_POWER_OF_TWO
One or more pools has a pg_num value that is not a power of two.
Although this is not strictly incorrect, it does lead to a less
balanced distribution of data because some PGs have roughly twice as
much data as others.
This is easily corrected by setting the pg_num value for the
affected pool(s) to a nearby power of two:
.. prompt:: bash $
ceph osd pool set
One or more pools should probably have more PGs, based on the amount
of data that is currently stored in the pool. This can lead to
suboptimal distribution and balance of data across the OSDs in the
cluster, and similarly reduce overall performance. This warning is
generated if the pg_autoscale_mode property on the pool is set to
warn.
To disable the warning, you can disable auto-scaling of PGs for the
pool entirely with:
.. prompt:: bash $
ceph osd pool set choosing-number-of-placement-groups and
:ref:pg-autoscaler for more information.
TOO_MANY_PGS
The number of PGs in use in the cluster is above the configurable
threshold of mon_max_pg_per_osd PGs per OSD. If this threshold is
exceed the cluster will not allow new pools to be created, pool pg_num to
be increased, or pool replication to be increased (any of which would lead to
more PGs in the cluster). A large number of PGs can lead
to higher memory utilization for OSD daemons, slower peering after
cluster state changes (like OSD restarts, additions, or removals), and
higher load on the Manager and Monitor daemons.
The simplest way to mitigate the problem is to increase the number of
OSDs in the cluster by adding more hardware. Note that the OSD count
used for the purposes of this health check is the number of “in” OSDs,
so marking “out” OSDs “in” (if there are any) can also help:
.. prompt:: bash $
ceph osd in <osd id(s)>
Please refer to :ref:choosing-number-of-placement-groups for more
information.
POOL_TOO_MANY_PGS
One or more pools should probably have more PGs, based on the amount
of data that is currently stored in the pool. This can lead to higher
memory utilization for OSD daemons, slower peering after cluster state
changes (like OSD restarts, additions, or removals), and higher load
on the Manager and Monitor daemons. This warning is generated if the
pg_autoscale_mode property on the pool is set to warn.
To disable the warning, you can disable auto-scaling of PGs for the
pool entirely with:
.. prompt:: bash $
ceph osd pool set choosing-number-of-placement-groups and
:ref:pg-autoscaler for more information.
POOL_TARGET_SIZE_BYTES_OVERCOMMITTED
One or more pools have a target_size_bytes property set to
estimate the expected size of the pool,
but the value(s) exceed the total available storage (either by
themselves or in combination with other pools’ actual usage).
This is usually an indication that the target_size_bytes value for
the pool is too large and should be reduced or set to zero with:
.. prompt:: bash $
ceph osd pool set specifying_pool_target_size.
POOL_HAS_TARGET_SIZE_BYTES_AND_RATIO
One or more pools have both target_size_bytes and
target_size_ratio set to estimate the expected size of the pool.
Only one of these properties should be non-zero. If both are set,
target_size_ratio takes precedence and target_size_bytes is
ignored.
To reset target_size_bytes to zero:
.. prompt:: bash $
ceph osd pool set specifying_pool_target_size.
TOO_FEW_OSDS
The number of OSDs in the cluster is below the configurable
threshold of osd_pool_default_size.
SMALLER_PGP_NUM
One or more pools has a pgp_num value less than pg_num. This
is normally an indication that the PG count was increased without
also increasing the placement behavior.
This is sometimes done deliberately to separate out the split step
when the PG count is adjusted from the data migration that is needed
when pgp_num is changed.
This is normally resolved by setting pgp_num to match pg_num,
triggering the data migration, with:
.. prompt:: bash $
ceph osd pool set
One or more pools has an average number of objects per PG that is
significantly higher than the overall cluster average. The specific
threshold is controlled by the mon_pg_warn_max_object_skew
configuration value.
This is usually an indication that the pool(s) containing most of the
data in the cluster have too few PGs, and/or that other pools that do
not contain as much data have too many PGs. See the discussion of
TOO_MANY_PGS above.
The threshold can be raised to silence the health warning by adjusting
the mon_pg_warn_max_object_skew config option on the managers.
The health warning will be silenced for a particular pool if
pg_autoscale_mode is set to on.
POOL_APP_NOT_ENABLED
A pool exists that contains one or more objects but has not been
tagged for use by a particular application.
Resolve this warning by labeling the pool for use by an application. For
example, if the pool is used by RBD,:
.. prompt:: bash $
rbd pool init associate-pool-to-application.
POOL_FULL
One or more pools has reached (or is very close to reaching) its
quota. The threshold to trigger this error condition is controlled by
the mon_pool_quota_crit_threshold configuration option.
Pool quotas can be adjusted up or down (or removed) with:
.. prompt:: bash $
ceph osd pool set-quota
One or more pools is approaching a configured fullness threshold.
One threshold that can trigger this warning condition is the
mon_pool_quota_warn_threshold configuration option.
Pool quotas can be adjusted up or down (or removed) with:
.. prompt:: bash $
ceph osd pool set-quota mon_osd_nearfull_ratio and mon_osd_full_ratio. Visit the
:ref:storage-capacity and :ref:no-free-drive-space documents for details
and resolution.
OBJECT_MISPLACED
One or more objects in the cluster is not stored on the node the cluster would like it to be stored on. This is an indication that data migration due to some recent cluster change has not yet completed. Misplaced data is not a dangerous condition in and of itself; data consistency is never at risk, and old copies of objects are never removed until the desired number of new copies (in the desired locations) are present. OBJECT_UNFOUND
One or more objects in the cluster cannot be found. Specifically, the
OSDs know that a new or updated copy of an object should exist, but a
copy of that version of the object has not been found on OSDs that are
currently online.
Read or write requests to unfound objects will block.
Ideally, a down OSD can be brought back online that has the more
recent copy of the unfound object. Candidate OSDs can be identified from the
peering state for the PG(s) responsible for the unfound object:
.. prompt:: bash $
ceph tell failures-osd-unfound for more information.
SLOW_OPS
One or more OSD or monitor requests is taking a long time to process. This can
be an indication of extreme load, a slow storage device, or a software
bug.
The request queue for the daemon in question can be queried with the
following command, executed from the daemon’s host:
.. prompt:: bash $
ceph daemon osd.
One or more PGs has not been scrubbed recently. PGs are normally scrubbed
within every configured interval specified by
:confval:osd_scrub_max_interval globally. This
interval can be overridden on per-pool basis with
:confval:scrub_max_interval. The warning triggers when
mon_warn_pg_not_scrubbed_ratio percentage of interval has elapsed without a
scrub since it was due.
PGs will not scrub if they are not flagged as clean, which may
happen if they are misplaced or degraded (see PG_AVAILABILITY and
PG_DEGRADED above).
You can manually initiate a scrub of a clean PG with::
ceph pg scrub
One or more PGs has not been deep scrubbed recently. PGs are normally
scrubbed every :confval:osd_deep_scrub_interval seconds, and this warning
triggers when mon_warn_pg_not_deep_scrubbed_ratio percentage of interval has elapsed
without a scrub since it was due.
PGs will not (deep) scrub if they are not flagged as clean, which may
happen if they are misplaced or degraded (see PG_AVAILABILITY and
PG_DEGRADED above).
You can manually initiate a scrub of a clean PG with:
.. prompt:: bash $
ceph pg deep-scrub
PG_SLOW_SNAP_TRIMMING
The snapshot trim queue for one or more PGs has exceeded the
configured warning threshold. This indicates that either an extremely
large number of snapshots were recently deleted, or that the OSDs are
unable to trim snapshots quickly enough to keep up with the rate of
new snapshot deletions.
The warning threshold is controlled by the
mon_osd_snap_trim_queue_warn_on option (default: 32768).
This warning may trigger if OSDs are under excessive load and unable
to keep up with their background work, or if the OSDs’ internal
metadata database is heavily fragmented and unable to perform. It may
also indicate some other performance issue with the OSDs.
The exact size of the snapshot trim queue is reported by the
snaptrimq_len field of ceph pg ls -f json-detail.
Miscellaneous #
RECENT_CRASH
One or more Ceph daemons has crashed recently, and the crash has not
yet been archived (acknowledged) by the administrator. This may
indicate a software bug, a hardware problem (e.g., a failing disk), or
some other problem.
New crashes can be listed with:
.. prompt:: bash $
ceph crash ls-new
Information about a specific crash can be examined with:
.. prompt:: bash $
ceph crash info ceph crash ls but not
ceph crash ls-new.
The time period for what “recent” means is controlled by the option
mgr/crash/warn_recent_interval (default: two weeks).
These warnings can be disabled entirely with:
.. prompt:: bash $
ceph config set mgr/crash/warn_recent_interval 0
RECENT_MGR_MODULE_CRASH
One or more ceph-mgr modules has crashed recently, and the crash as
not yet been archived (acknowledged) by the administrator. This
generally indicates a software bug in one of the software modules run
inside the ceph-mgr daemon. Although the module that experienced the
problem maybe be disabled as a result, the function of other modules
is normally unaffected.
As with the RECENT_CRASH health alert, the crash can be inspected with:
.. prompt:: bash $
ceph crash info ceph crash ls but not
ceph crash ls-new.
The time period for what “recent” means is controlled by the option
mgr/crash/warn_recent_interval (default: two weeks).
These warnings can be disabled entirely with:
.. prompt:: bash $
ceph config set mgr/crash/warn_recent_interval 0
TELEMETRY_CHANGED
Telemetry has been enabled, but the contents of the telemetry report
have changed since that time, so telemetry reports will not be sent.
The Ceph developers periodically revise the telemetry feature to
include new and useful information, or to remove information found to
be useless or sensitive. If any new information is included in the
report, Ceph will require the administrator to re-enable telemetry to
ensure they have an opportunity to (re)review what information will be
shared.
To review the contents of the telemetry report:
.. prompt:: bash $
ceph telemetry show
Note that the telemetry report consists of several optional channels
that may be independently enabled or disabled. For more information, see
:ref:telemetry.
To re-enable telemetry (and make this warning go away):
.. prompt:: bash $
ceph telemetry on
To disable telemetry (and make this warning go away):
.. prompt:: bash $
ceph telemetry off
AUTH_BAD_CAPS
One or more auth users has capabilities that cannot be parsed by the
monitor. This generally indicates that the user will not be
authorized to perform any action with one or more daemon types.
This error is mostly likely to occur after an upgrade if the
capabilities were set with an older version of Ceph that did not
properly validate their syntax, or if the syntax of the capabilities
has changed.
The user in question can be removed with:
.. prompt:: bash $
ceph auth rm user-management.
OSD_NO_DOWN_OUT_INTERVAL
The mon_osd_down_out_interval option is set to zero, which means
that the system will not automatically perform any repair or healing
operations after an OSD fails. Instead, an administrator (or some
other external entity) will need to manually mark down OSDs as ‘out’
(i.e., via ceph osd out <osd-id>) in order to trigger recovery.
This option is normally set to five or ten minutes–enough time for a
host to power-cycle or reboot.
This warning can silenced by setting the
mon_warn_on_osd_down_out_interval_zero to false:
.. prompt:: bash $
ceph config global mon mon_warn_on_osd_down_out_interval_zero false
DASHBOARD_DEBUG
The Dashboard debug mode is enabled. This means, if there is an error while processing a REST API request, the HTTP error response contains a Python traceback. This behaviour should be disabled in production environments because such a traceback might contain and expose sensible information. The debug mode can be disabled with: .. prompt:: bash $ ceph dashboard debug disable
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