Appendix I. Ceph scrubbing options
Ceph ensures data integrity by scrubbing placement groups. The following are the Ceph scrubbing options that can be adjusted to increase or decrease scrubbing operations.
- osd_max_scrubs
- Description
- The maximum number of simultaneous scrub operations for a Ceph OSD Daemon.
- Type
- integer
- Default
- 1
- osd_scrub_begin_hour
- Description
-
The specific hour at which the scrubbing begins. Along with
osd_scrub_end_hour, you can define a time window in which the scrubs can happen. Useosd_scrub_begin_hour = 0andosd_scrub_end_hour = 0to allow scrubbing the entire day. - Type
- integer
- Default
- 0
- Allowed range
-
[0, 23]
- osd_scrub_end_hour
- Description
-
The specific hour at which the scrubbing ends. Along with
osd_scrub_begin_hour, you can define a time window, in which the scrubs can happen. Useosd_scrub_begin_hour = 0andosd_scrub_end_hour = 0to allow scrubbing for the entire day. - Type
- integer
- Default
- 0
- Allowed range
-
[0, 23]
- osd_scrub_begin_week_day
- Description
-
The specific day on which the scrubbing begins. 0 = Sunday, 1 = Monday, etc. Along with “osd_scrub_end_week_day”, you can define a time window in which scrubs can happen. Use
osd_scrub_begin_week_day = 0andosd_scrub_end_week_day = 0to allow scrubbing for the entire week. - Type
- integer
- Default
- 0
- Allowed range
-
[0, 6]
- osd_scrub_end_week_day
- Description
-
This defines the day on which the scrubbing ends. 0 = Sunday, 1 = Monday, etc. Along with
osd_scrub_begin_week_day, they define a time window, in which the scrubs can happen. Useosd_scrub_begin_week_day = 0andosd_scrub_end_week_day = 0to allow scrubbing for the entire week. - Type
- integer
- Default
- 0
- Allowed range
-
[0, 6]
- osd_scrub_during_recovery
- Description
-
Allow scrub during recovery. Setting this to
falsedisables scheduling new scrub, and deep-scrub, while there is an active recovery. The already running scrubs continue which is useful to reduce load on busy storage clusters. - Type
- boolean
- Default
- false
- osd_scrub_load_threshold
- Description
- The normalized maximum load. Scrubbing does not happen when the system load, as defined by getloadavg() / number of online CPUs, is higher than this defined number.
- Type
- float
- Default
- 0.5
- osd_scrub_min_interval
- Description
- The minimal interval in seconds for scrubbing the Ceph OSD daemon when the Ceph storage Cluster load is low.
- Type
- float
- Default
- 1 day
- osd_scrub_max_interval
- Description
- The maximum interval in seconds for scrubbing the Ceph OSD daemon irrespective of cluster load.
- Type
- float
- Default
- 7 days
- osd_scrub_chunk_min
- Description
- The minimal number of object store chunks to scrub during a single operation. Ceph blocks writes to a single chunk during scrub.
- type
- integer
- Default
- 5
- osd_scrub_chunk_max
- Description
- The maximum number of object store chunks to scrub during a single operation.
- type
- integer
- Default
- 25
- osd_scrub_sleep
- Description
- Time to sleep before scrubbing the next group of chunks. Increasing this value slows down the overall rate of scrubbing, so that client operations are less impacted.
- type
- float
- Default
- 0.0
- osd_deep_scrub_interval
- Description
-
The interval for
deepscrubbing, fully reading all data. Theosd_scrub_load_thresholddoes not affect this setting. - type
- float
- Default
- 7 days
- osd_scrub_interval_randomize_ratio
- Description
-
Add a random delay to
osd_scrub_min_intervalwhen scheduling the next scrub job for a placement group. The delay is a random value less thanosd_scrub_min_interval*osd_scrub_interval_randomized_ratio. The default setting spreads scrubs throughout the allowed time window of[1, 1.5]*osd_scrub_min_interval. - type
- float
- Default
- 0.5
- osd_deep_scrub_stride
- Description
- Read size when doing a deep scrub.
- type
- size
- Default
- 512 KB
- osd_scrub_auto_repair_num_errors
- Description
- Auto repair does not occur if more than these many errors are found.
- type
- integer
- Default
- 5
- osd_scrub_auto_repair
- Description
-
Setting this to
trueenables automatic Placement Group (PG) repair when errors are found by scrubs or deep-scrubs. However, if more thanosd_scrub_auto_repair_num_errorserrors are found, a repair is NOT performed. This option is for periodic scrubs and not for operator-initiated scrubs. - type
- boolean
- Default
- false
