MDS Config Reference
- mds_cache_mid
The insertion point for new items in the cache LRU (from the top).
- type
float- default
0.7
- mds_dir_max_commit_size
The maximum size of a directory update before Ceph breaks it into smaller transactions (MB).
- type
int- default
10
- mds_dir_max_entries
The maximum number of entries before any new entries are rejected with ENOSPC.
- type
uint- default
0
- mds_decay_halflife
rate of decay for temperature counters on each directory for balancing
- type
float- default
5.0
- mds_beacon_interval
interval in seconds between MDS beacon messages sent to monitors
- type
float- default
4.0
- mds_beacon_grace
The interval without beacons before Ceph declares an MDS laggy (and possibly replace it).
- type
float- default
15.0
- mon_mds_blocklist_interval
The blocklist duration for failed MDSs in the OSD map. Note, this controls how long failed MDS daemons will stay in the OSDMap blocklist. It has no effect on how long something is blocklisted when the administrator blocklists it manually. For example,
ceph osd blocklist addwill still use the default blocklist time.- type
float- default
1 day- min
1_hr
- mds_reconnect_timeout
timeout in seconds to wait for clients to reconnect during MDS reconnect recovery state
- type
float- default
45.0
- mds_tick_interval
How frequently the MDS performs internal periodic tasks.
- type
float- default
5.0
- mds_dirstat_min_interval
The minimum interval (in seconds) to try to avoid propagating recursive stats up the tree.
- type
float- default
1.0
- mds_scatter_nudge_interval
How quickly dirstat changes propagate up.
- type
float- default
5.0
- mds_client_prealloc_inos
The number of inode numbers to preallocate per client session.
- type
int- default
1000
- mds_early_reply
Determines whether the MDS should allow clients to see request results before they commit to the journal.
- type
bool- default
true
- mds_default_dir_hash
The function to use for hashing files across directory fragments.
- type
int- default
2
- mds_log_skip_corrupt_events
Determines whether the MDS should try to skip corrupt journal events during journal replay.
- type
bool- default
false
- mds_log_max_events
The maximum events in the journal before we initiate trimming. Set to
-1to disable limits.- type
int- default
-1
- mds_log_max_segments
The maximum number of segments (objects) in the journal before we initiate trimming. Set to
-1to disable limits.- type
uint- default
128
- mds_bal_sample_interval
Determines how frequently to sample directory temperature (for fragmentation decisions).
- type
float- default
3.0
- mds_bal_replicate_threshold
The maximum temperature before Ceph attempts to replicate metadata to other nodes.
- type
float- default
8000.0
- mds_bal_unreplicate_threshold
The minimum temperature before Ceph stops replicating metadata to other nodes.
- type
float- default
0.0
- mds_bal_split_size
The maximum directory size before the MDS will split a directory fragment into smaller bits.
- type
int- default
10000
- mds_bal_split_rd
The maximum directory read temperature before Ceph splits a directory fragment.
- type
float- default
25000.0
- mds_bal_split_wr
The maximum directory write temperature before Ceph splits a directory fragment.
- type
float- default
10000.0
- mds_bal_split_bits
The number of bits by which to split a directory fragment.
- type
int- default
3- allowed range
[1, 24]
- mds_bal_merge_size
The minimum directory size before Ceph tries to merge adjacent directory fragments.
- type
int- default
50
- mds_bal_interval
The frequency (in seconds) of workload exchanges between MDSs.
- type
int- default
10
- mds_bal_fragment_interval
The delay (in seconds) between a fragment being eligible for split or merge and executing the fragmentation change.
- type
int- default
5
- mds_bal_fragment_fast_factor
The ratio by which frags may exceed the split size before a split is executed immediately (skipping the fragment interval)
- type
float- default
1.5
- mds_bal_fragment_size_max
The maximum size of a fragment before any new entries are rejected with ENOSPC.
- type
int- default
100000
- mds_bal_idle_threshold
The minimum temperature before Ceph migrates a subtree back to its parent.
- type
float- default
0.0
- mds_bal_max
The number of iterations to run balancer before Ceph stops. (used for testing purposes only)
- type
int- default
-1
- mds_bal_max_until
The number of seconds to run balancer before Ceph stops. (used for testing purposes only)
- type
int- default
-1
- mds_bal_mode
The method for calculating MDS load.
0= Hybrid.1= Request rate and latency.2= CPU load.
- type
int- default
0
- mds_bal_min_rebalance
The minimum subtree temperature before Ceph migrates.
- type
float- default
0.1
- mds_bal_min_start
The minimum subtree temperature before Ceph searches a subtree.
- type
float- default
0.2
- mds_bal_need_min
The minimum fraction of target subtree size to accept.
- type
float- default
0.8
- mds_bal_need_max
The maximum fraction of target subtree size to accept.
- type
float- default
1.2
- mds_bal_midchunk
Ceph will migrate any subtree that is larger than this fraction of the target subtree size.
- type
float- default
0.3
- mds_bal_minchunk
Ceph will ignore any subtree that is smaller than this fraction of the target subtree size.
- type
float- default
0.001
- mds_replay_interval
The journal poll interval when in standby-replay mode. (“hot standby”)
- type
float- default
1.0
- mds_shutdown_check
The interval for polling the cache during MDS shutdown.
- type
int- default
0
- mds_thrash_exports
Ceph will randomly export subtrees between nodes (testing only).
- type
int- default
0
- mds_thrash_fragments
Ceph will randomly fragment or merge directories.
- type
int- default
0
- mds_dump_cache_on_map
Ceph will dump the MDS cache contents to a file on each MDSMap.
- type
bool- default
false
- mds_dump_cache_after_rejoin
Ceph will dump MDS cache contents to a file after rejoining the cache (during recovery).
- type
bool- default
false
- mds_verify_scatter
Ceph will assert that various scatter/gather invariants are
true(developers only).- type
bool- default
false
- mds_debug_scatterstat
Ceph will assert that various recursive stat invariants are
true(for developers only).- type
bool- default
false
- mds_debug_frag
Ceph will verify directory fragmentation invariants when convenient (developers only).
- type
bool- default
false
- mds_debug_auth_pins
The debug auth pin invariants (for developers only).
- type
bool- default
false
- mds_debug_subtrees
The debug subtree invariants (for developers only).
- type
bool- default
false
- mds_kill_mdstable_at
Ceph will inject MDS failure in MDSTable code (for developers only).
- type
int- default
0
- mds_kill_export_at
Ceph will inject MDS failure in the subtree export code (for developers only).
- type
int- default
0
- mds_kill_import_at
Ceph will inject MDS failure in the subtree import code (for developers only).
- type
int- default
0
- mds_kill_link_at
Ceph will inject MDS failure in hard link code (for developers only).
- type
int- default
0
- mds_kill_rename_at
Ceph will inject MDS failure in the rename code (for developers only).
- type
int- default
0
- mds_inject_skip_replaying_inotable
Ceph will skip replaying the inotable when replaying the journal, and the premary MDS will crash, while the replacing MDS won’t. (for testing only).
- type
bool- default
false
- mds_kill_skip_replaying_inotable
Ceph will skip replaying the inotable when replaying the journal, and the premary MDS will crash, while the replacing MDS won’t. (for testing only).
- type
bool- default
false
- mds_wipe_sessions
Ceph will delete all client sessions on startup (for testing only).
- type
bool- default
false
- mds_wipe_ino_prealloc
Ceph will delete ino preallocation metadata on startup (for testing only).
- type
bool- default
false
- mds_skip_ino
The number of inode numbers to skip on startup (for testing only).
- type
int- default
0
- mds_min_caps_per_client
minimum number of capabilities a client may hold
- type
uint- default
100
- mds_symlink_recovery
Stores symlink target on the first data object of symlink file. Allows recover of symlink using recovery tools.
- type
bool- default
true