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File Content
- gc_max_sleep_time This tuning parameter controls the maximum sleep
+ gc_urgent_sleep_time This parameter controls sleep time for gc_urgent.
+ 500 ms is set by default. See above gc_urgent.
+
+ gc_min_sleep_time This tuning parameter controls the minimum sleep
time for the garbage collection thread. Time is
in milliseconds.
- gc_min_sleep_time This tuning parameter controls the minimum sleep
+ gc_max_sleep_time This tuning parameter controls the maximum sleep
time for the garbage collection thread. Time is
in milliseconds.
to 1, background thread starts to do GC by given
gc_urgent_sleep_time interval.
- gc_urgent_sleep_time This parameter controls sleep time for gc_urgent.
- 500 ms is set by default. See above gc_urgent.
-
reclaim_segments This parameter controls the number of prefree
segments to be reclaimed. If the number of prefree
segments is larger than the number of segments
checkpoint is triggered, and issued during the
checkpoint. By default, it is disabled with 0.
- trim_sections This parameter controls the number of sections
+ discard_granularity This parameter controls the granularity of discard
+ command size. It will issue discard commands iif
+ the size is larger than given granularity. Its
+ unit size is 4KB, and 4 (=16KB) is set by default.
+ The maximum value is 128 (=512KB).
+
+ reserved_blocks This parameter indicates the number of blocks that
+ f2fs reserves internally for root.
+
+ batched_trim_sections This parameter controls the number of sections
to be trimmed out in batch mode when FITRIM
conducts. 32 sections is set by default.
the number is less than this value, it triggers
in-place-updates.
+ min_seq_blocks This parameter controls the threshold to serialize
+ write IOs issued by multiple threads in parallel.
+
+ min_hot_blocks This parameter controls the threshold to allocate
+ a hot data log for pending data blocks to write.
+
+ min_ssr_sections This parameter adds the threshold when deciding
+ SSR block allocation. If this is large, SSR mode
+ will be enabled early.
+
+ ram_thresh This parameter controls the memory footprint used
+ by free nids and cached nat entries. By default,
+ 10 is set, which indicates 10 MB / 1 GB RAM.
+
+ ra_nid_pages When building free nids, F2FS reads NAT blocks
+ ahead for speed up. Default is 0.
+
+ dirty_nats_ratio Given dirty ratio of cached nat entries, F2FS
+ determines flushing them in background.
+
max_victim_search This parameter controls the number of trials to
find a victim segment when conducting SSR and
cleaning operations. The default value is 4096
which covers 8GB block address range.
+ migration_granularity For large-sized sections, F2FS can stop GC given
+ this granularity instead of reclaiming entire
+ section.
+
dir_level This parameter controls the directory level to
support large directory. If a directory has a
number of files, it can reduce the file lookup
Otherwise, it needs to decrease this value to
reduce the space overhead. The default value is 0.
- ram_thresh This parameter controls the memory footprint used
- by free nids and cached nat entries. By default,
- 10 is set, which indicates 10 MB / 1 GB RAM.
+ cp_interval F2FS tries to do checkpoint periodically, 60 secs
+ by default.
+
+ idle_interval F2FS detects system is idle, if there's no F2FS
+ operations during given interval, 5 secs by
+ default.
+
+ discard_idle_interval F2FS detects the discard thread is idle, given
+ time interval. Default is 5 secs.
+
+ gc_idle_interval F2FS detects the GC thread is idle, given time
+ interval. Default is 5 secs.
+
+ umount_discard_timeout When unmounting the disk, F2FS waits for finishing
+ queued discard commands which can take huge time.
+ This gives time out for it, 5 secs by default.
+
+ iostat_enable This controls to enable/disable iostat in F2FS.
+
+ readdir_ra This enables/disabled readahead of inode blocks
+ in readdir, and default is enabled.
+
+ gc_pin_file_thresh This indicates how many GC can be failed for the
+ pinned file. If it exceeds this, F2FS doesn't
+ guarantee its pinning state. 2048 trials is set
+ by default.
+
+ extension_list This enables to change extension_list for hot/cold
+ files in runtime.
+
+ inject_rate This controls injection rate of arbitrary faults.
+
+ inject_type This controls injection type of arbitrary faults.
+
+ dirty_segments This shows # of dirty segments.
+
+ lifetime_write_kbytes This shows # of data written to the disk.
+
+ features This shows current features enabled on F2FS.
+
+ current_reserved_blocks This shows # of blocks currently reserved.
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USAGE