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.
and bio_inbed fields to 0. Without this change we can end up with
I/O leakage in some rare situations.
I tested this change by putting failure probability mechanism simlar
to this used in NOP class into g_clone_bio(9) function, so it was
able to return NULL with the given probability.
Discussed with: phk
bio_driver1 (as all the rest).
This introduced a small memory leak, but it wasn't really critical,
because maximum memory for g_stripe_zone is always set, so after few
requests gstripe was working in "economic" mode.
It allows to fix problems when last provider's sector is shared between few
providers.
- Bump version number for CONCAT and STRIPE and add code for backward
compatibility.
- Do not bump version number of MIRROR, as it wasn't officially introduced yet.
Even if someone started to play with it, there is no big deal, because
wrong MD5 sum of metadata will deny those providers.
- Update manual pages.
- Add version history to g_(stripe|concat).h files.
