On Tue, Jan 30, 2018 at 01:52:49PM -0600, Jeremy Linton wrote: > Have you tried this with a '-o nfsvers=3' during mount? Did that help? > > I noticed a large decrease in my kernel build times across NFS/lan a while > back after a machine/kernel/10g upgrade. After playing with mount/export > options filesystem tuning/etc, I got to this point of timing a bunch of > these operations vs the older machine, at which point I discovered that > simply backing down to NFSv3 solved the problem. > > AKA a nfsv3 server on a 10 year old 4 disk xfs RAID5 on 1Gb ethernet, was > slower than a modern machine with a 8 disk xfs RAID5 on 10Gb on nfsv4. The > effect was enough to change a kernel build from ~45 minutes down to less > than 5. Did you mean "faster than"? Definitely worth trying, though I wouldn't expect it to make that big a difference in the untarring-a-kernel-tree case--I think the only RPC avoided in the v3 case would be the CLOSE, and it should be one of the faster ones. In the kernel compile case there's probably also a lot of re-opening and re-reading files too? NFSv4 is chattier there too. Read delegations should help compensate, but we need to improve the heuristics that decide when they're given out. All that aside I can't think what would explain that big a difference (45 minutes vs. 5). It might be interesting to figure out what happened. --b. _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
