[ovirt-devel] [VDSM] All tests using directio fail on CI

[Anton Marchukov]

>
>
> > The node will be offline for now until we agree on what to do.
> > An option is to abandon RAM disks completely as we didn't find
> > any performance benefits from using them so far.
>
> That's very surprising. On my case it doubles the performance,  at least.
> But I assume my storage (single disk) is far slower than yours.
>

What amount of RAM you had available to Linux file system cache and were
there any previous runs so Linux were able to put any mock caches into the
RAM cache?

Besides the possible difference in disk speeds I think the second factor is
this Linux fs cache that basically create an analog of RAM disk on the fly.

Those two things might explain why we do not see any performance
improvement from RAM drives in our case.

Anton.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/infra/attachments/20160929/bd861cc0/attachment.html>