How many demand read didn't have to wait for I/O
because of predictive prefetch. (more is better)
zfetch kstats have been similified to hits, misses, and max_streams,
with max_streams representing times when we were not able to create
new stream because we already have the maximum number of sequences
for a file.
The sysctl variable/loader tunable vfs.zfs.zfetch.block_cap have been
replaced by vfs.zfs.zfetch.max_distance, which controls maximum bytes
to prefetch per stream.
287707 by mav:
CTL documentation update, mostly for HA.
287706 by delphij:
MFV r287699: 6214 zpools going south
In r286570 (MFV of r277426) an unprotected write to b_flags to
set the compression mode was introduced. This would open a race
window where data is partially decompressed, modified, checksummed
and written to the pool, resulting in pool corruption due to the