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:
- 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".
- /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