ZVOL with volblocksize=64k+ results in data corruption [was Re: Resolving errors with ZVOL-s]

[Andriy Gapon]

On 21/09/2017 23:00, Wiktor Niesiobedzki wrote:
> I've conducted additional tests. It looks like when I create volumes with
> following commands:
> # zfs create -V50g -o volmode=dev -o volblocksize=64k -o compression=off -o
> com.sun:auto-snapshot=false tank/test
> # zfs create -V50g -o volmode=dev -o volblocksize=128k -o compression=off
> -o com.sun:auto-snapshot=false tank/test
> 
> I'm able to get checksum errors quite reliably in 2-12h of normal work of
> the volume. I tested also different volbocksizes:
> # zfs create -V50g -o volmode=dev -o volblocksize=32k -o compression=off -o
> com.sun:auto-snapshot=false tank/test
> # zfs create -V50g -o volmode=dev -o volblocksize=8k -o compression=off -o
> com.sun:auto-snapshot=false tank/test
> # zfs create -V50g -o volmode=dev -o volblocksize=4k -o compression=off -o
> com.sun:auto-snapshot=false tank/test
> 
> And gave them more than 24h of work with no apparent errors (I also moved
> other volumes to 4k and they did not show any checksum errors for more than
> 2 weeks).
> 
> I was running with volblocksize=128k from January this year. The problem
> started to appear only after I updated from 11.0 to 11.1.
> 
> Should I file bug report for this? What additional information should I
> gather?

Are you able to patch your version of FreeBSD?
Could you please try https://svnweb.freebsd.org/changeset/base/323918
and see if it makes things better?

Thanks!
-- 
Andriy Gapon