[DRBD-user] Slow NFS behaviour (0.7.5)

Philipp Reisner philipp.reisner at linbit.com
Tue Nov 23 18:04:32 CET 2004

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


On Tuesday 23 November 2004 18:02, Philipp Reisner wrote:
> > I'm mounting sync. I'm afraid that since we need the NFS failover between
> > the servers, A + async may not be an option for us :/ Our users would eat
> > us alive.
>
> This is probabely the reason for you bad performance.
>
> My choice would be normal (=async) NFS mount plus DRBD in protocol C.
>
> This has the same semantics as a local filesystem: The return of the
> write system call means that the data is in the OS's buffers, the
> return of the fsync()/fdatasync() syscall means that it is on disk.
>
> Do you mount your local filesystems with the "sync" option ?
> I do not do this. I see this as the common semantics which under
> Unix/Linux.
>

I wanted to add: There only way to run a "sync" mounted FS with
tolerable performance is to use a controller with battery backed-
up RAM.

-philipp
-- 
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: LINBIT Information Technologies GmbH          Fax +43-1-8178292-82 :
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