NFS Efficiency

[elija]

We have various NFS shares mounted on to a couple of different servers and I am wondering about efficiency.

The current situation is

/data/
    avatars    (Exported and mounted remotely)
        user1
        user2
        ... snip ...
        user100000
    file-store  (Exported and mounted remotely)
        user1
        user2
        ... snip ...
        user100000
    images     (Exported and mounted remotely)
        user1
        user2
        ... snip ...
        user100000

I'm wondering if the following is better or not?

/data/    (Exported and mounted remotely)
    avatars    
        user1
        user2
        ... snip ...
        user100000
    file-store
        user1
        user2
        ... snip ...
        user100000
    images
        user1
        user2
        ... snip ...
        user100000

Ultimately, I'm pushing for something like storing the files locally and using inotifyd for synchronisation which I think would be better than either of the above

[gaurav-joseph]

i think the second will be better instead of exporting three

[Irithori]

I would keep the separation of the three exports as each has its specific purpose (judging from the name).
Then, if the situation calls for it, then you can relatively simple offload these three exports to a nfs server each.
Which would also lessen the impact of the downtime of one of those machines to the nfs service as a whole.
(e.g. only avatars are unavailabe. The rest is working.)
Also processing is more specific. On a file-store nfs machine will be only file-store related cronjobs, etc.

About inotify aka csync2 + lsyncd combination:
Possible, but needs
- careful setup, especially with more than two nodes and in an "all can write" mode:
Two nodes change the same file at the same time. Who wins?
- periodic "full syncs", to be sure that really all files are on each machine. Think network issues, one machine getīs rebooted, etc
- monitoring of the syncs

Tbh, with lsyncd I would go so far to build a slave nfs machine, that I can use for a quick service recovery.
Aka: A master syncs to a slave, end of story.

[elija]

Thanks. Lots of food for thought here.