On Fri 13-05-16 12:29:10, Jens Axboe wrote:

Thanks Jan, this is great and super useful! I'm revamping certain parts of
it to deal with write back caching better, and I'll take a look at the
regressions that you reported.

What kind of SSD is this? I'm assuming it's SATA (QD=32), and then it would
probably be a safe assumption that it's flagging itself as having a volatile
write back cache, would that be a correct assumption?

Yes, it is SATA with writeback cache.

Are you using scsi-mq, or do you have an IO scheduler attached to it?

The disk was using IO scheduler, however at this point I'm not 100% sure
which scheduler (deadline or cfq) was the default one for the distro that
was installed. The machine is currently testing something else so I cannot
reinstall it and check. Maybe I can rerun some tests later in the week when
the machine gets freed with scsi-mq or deadline IO scheduler so that we
have 100% certain config.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR