[Gluster-users] Gluster v 3.3 with KVM and High Availability

Brian Candler B.Candler at pobox.com
Thu Jul 12 09:52:53 UTC 2012

On Thu, Jul 12, 2012 at 12:04:24PM +0300, Samuli Heinonen wrote:
> >So am I kidding myself that approaching 45-50MB/s with a
> >FUSE based Gluster mount and using cache=writethrough is actually
> >a safe thing to do really?
> When using writethrough the data is written to cache but not marked
> finished before it has hit the disk. Data in cache can be then used
> to speed up read operations. So I would consider it pretty safe, but
> perhaps someone else can explain it better?

I don't believe he is getting that speed with cache=writethrough.  I think
he means cache=writeback.

"QEMU also supports a wide variety of caching modes. Writeback is useful for
testing but does not offer storage guarantees. Writethrough (the default) is
safer, and relies on the host cache."

More information about the Gluster-users mailing list