Il 20-08-2017 15:07 Wols Lists ha scritto:
Which is exactly what my "force integrity check on read" proposal would
have achieved, but that generated so much heat and argument IN FAVOUR
of
returning possibly corrupt data that I'll probably get flamed to high
heaven if I bring it back up again.
I think the aversion to such an approach is due to:
a) a *big* performance degradation (you get the IOPs of a single disk);
b) the existence on all-encompassing checksummed filesystems as ZFS and
BTRFS[1];
c) the difficulty to actually write such a code;
d) a understimating of how often can these data-corruption problem
happens in real life.
I can not really blame MDRAID for what it provides, as it is incredibly
flexible and very fast. Sure, a user-selectable option to auto
discover/correct corrupted data would be great, but it seems that this
is not the road MDRAID will ever take.
However, a possible solution would be to use dm-integrity on top of the
single component devices of an MDRAID array. Give at look at stratis[2],
it will be interesting...
[1] In the current state, I do not really trust BTRFS. I put much more
hopes on ZoL...
[2] https://stratis-storage.github.io/StratisSoftwareDesign.pdf
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti@xxxxxxxxxx - info@xxxxxxxxxx
GPG public key ID: FF5F32A8
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
