Actually, it can even cause some problems, because GEOM requires sectorsize
to be more than 0 on first access, not on provider creation, so we can skip
valid providers by doing this check here.
Reported by: Divacky Roman <xdivac02@stud.fit.vutbr.cz>
Sven Willenberger <sven@dmv.com>
Analogous to the drive level, give each volume and plex a worker thread
that picks up and processes incoming and completed BIOs.
This should fix the data corruption issues that have come up a few
weeks ago and improve performance, especially of RAID5 plexes.
The volume level needs a little work, though.
sectorsize in order to avoid a lot of checks around various divisions etc.
Enforce the sectorsize being > 0 with a KASSERT on successful open.
Fix scsi_cd.c to return 2k sectors when no media inserted.
verification of regular data when device is in complete state.
On verification error, EIO error is returned for the bio and sysctl
kern.geom.raid3.stat.parity_mismatch is increased.
Suggested by: phk
as well, even if device is in complete state.
I observe 40% of speed-up with this option for random read operations,
but slowdown for sequential reads.
Basically, without this option reading from a RAID3 device built from 5
components (c0-c4) looks like this:
Request no. Used components
1 c0+c1+c2+c3
2 c0+c1+c2+c3
3 c0+c1+c2+c3
With the new feature:
Request no. Used components
1 c0+c1+c2+c3
2 (c1^c2^c3^c4)+c1+c2+c3
3 c0+(c0^c2^c3^c4)+c2+c3
4 c0+c1+(c0^c1^c3^c4)+c3
5 c0+c1+c2+(c0^c1^c2^c4)
6 c0+c1+c2+c3
[...]
drive is known to the configuration check also if it already has a geom.
Without this check several needless geoms are created and valid
configuration data was overwritten.
This change obsoletes the need for a separate geom to taste an
offered provider and the consumer doesn't need to be opened with the
exclusive bit set.
- Remove kern.geom.mirror.sync_block_size sysctl. It is quite obvious that we
want to use the biggest size possible.
- Do not use UMA zone for sync data allocations. There could be only one
synchronization request per synchronized disk at a time, so allocate memory
for one request on whole synchronization process related to one disk.
Tested by synchronizing one component (out of three) and by synchronizing
two components (out of three) in parallel.
