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

Thu Jul 28 08:38:09 UTC 2016
Frank Thommen <lists.centos.de at drosera.ch>

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 

> 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.