On 07/28/2016 12:21 AM, Paul Heinlein wrote: > On Wed, 27 Jul 2016, Frank Thommen wrote: > >> Hello, >> >> does it in any respect (throughput/performance, cpu load, I/O load, >> resilience, ...) matter, if one mounts subdirectories of an NFS (v3) >> export into separate directories or if one just mounts the parent >> directory? >> >> I.e. like this: >> >> server: /export/base/a -> /mnt/a >> server: /export/base/b -> /mnt/b >> server: /export/base/c -> /mnt/c >> server: /export/base/d -> /mnt/d >> server: /export/base/e -> /mnt/e >> >> or simply like this: >> >> server:/export/base -> /mnt > > Performance wise, any bottleneck will almost certainly be tied to the > disks on the back end, not the nfs process itself. > > There are a couple good reasons for splitting up the mounts: > > 1. They can have different export restrictions (e.g., for different > client hosts, ro vs. rw permissions, user squashing). I'm not sure you can define individual restrictions for subdirectories of exported filesystems? In our case export permissions are set for "server:/export/base". > 2. /base/[a-e] live on different RAID arrays and might benefit from > different management cycles; that'd also be a case where multiple > exports might be a good idea. That said, I've never managed an > exported filesystem consisting of different arrays; we've always > exported at the RAID level or below. > Agreed, but this is not the case in our situation. frank