[CentOS] Mounting NFS subdirectories individually or just the parent?

[Paul Heinlein]

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.

-- 
Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/