[CentOS] NFS help

Mon Oct 24 14:29:25 UTC 2016
m.roth at 5-cent.us <m.roth at 5-cent.us>

Gordon Messmer wrote:
> On 10/24/2016 04:51 AM, mark wrote:
>> Absolutely add nobarrier, and see what happens.
>
> Using "nobarrier" might increase overall write throughput, but it
> removes an important integrity feature, increasing the risk of
> filesystem corruption on power loss.  I wouldn't recommend doing that
> unless your system is on a UPS, and you've tested and verified that it
> will perform an orderly shutdown when the UPS is on battery power and
> its charge is low.
>
As I noted in my original repost, that it needs to be on a UPS, and to
repeat myself, untaring a 107MB tarfile on an xfs filesystem mounted over
NFS, it was ->seven minutes<-, 100% repeatable, while after we added
nobarrier and remounted it, it was about ->40 seconds<-. That's *hugely*
significant.

      mark