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).
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.