m.roth at 5-cent.us wrote: > Matt Garman wrote: > >>We have a "compute cluster" of about 100 machines that do a read-only >>NFS mount to a big NAS filer (a NetApp FAS6280). The jobs running on >>these boxes are analysis/simulation jobs that constantly read data off >>the NAS. > > <snip> > *IF* I understand you, I've got one question: what parms are you using to > mount the storage? We had *real* performance problems when we went from 5 > to 6 - as in, unzipping a 26M file to 107M, while writing to an > NFS-mounted drive, went from 30 sec or so to a *timed* 7 min. The final > answer was that once we mounted the NFS filesystem with nobarrier in fstab > instead of default, the time dropped to 35 or 40 sec again. > > barrier is in 6, and tries to make writes atomic transactions; its intent > is to protect in case of things like power failure. Esp. if you're on > UPSes, nobarrier is the way to go. The server in this case isn't a Linux box with an ext4 file system - so that won't help ... James Pearson