NFS Mount Point Strategy?

[Robert Thurlow]

In <1990Nov10.144551.809 at alchemy.chem.utoronto.ca> system at alchemy.chem.utoronto.ca (System Admin (Mike Peterson)) writes:

>1) What options should I use on various systems for the mount command
>   (e.g. soft vs. hard, use bg or not, use 'hard,bg', retry counts,
>   timeouts)?

ALWAYS use "bg"; it just means your clients won't hang as badly on bootup
when a server is down.  I use "hard,intr" mounts for filesystems that are
writable so that I get the best data integrity while leaving people have a
chance to kill a hung process.  "soft,ro" is a nice combination for stuff
like man pages and reference sources that programs don't depend on.

>2) What directory structure is best for the actual mount points:
>   b) mount "system:/dir" on /nfs/system_dir and let the users refer to 
>      /system_dir/..... where /system_dir is a link to /nfs/system_dir
>      (so that the user reference point is 1 link removed from the
>      actual mount point)?

We actually use /rmt/<servername>/<fsname> so it's easier to figure
out where everything is, and we have a symlink from /<fsname> to
the actual mount point.  This is really important, since getwd()
and 'pwd' can hang if it stumbles across a remote mount point as
it walks up the tree looking for the right components.  If you can't
do symbolic links, you're kind of stuck, though.

>3) Does the answer to 2) depend on the answer to 1), and/or the
>   reliability of the systems involved?

Not really; do 'em all so they can screw you up as little as possible.
The most reliable systems still have to come down for PM every once 
in awhile.

>4) What naming schemes are used to handle the large number of potential
>   NFS mounts (for example, Physics/Astronomy/CITA here give each
>   disk/partition a name (of a tree from the forest), and Apollo
>   suggests systemname_dir; I can see advantages of both schemes since
>   the former makes disk names consistent everywhere and users don't
>   need to know what physical systems files really reside on, whereas 
>   the latter brings some order, especially for the sysadmin)?

I already described what we do for naming, and it seems to work well.
The single biggest thing you can do is use the Automounter if you have
one on any of your clients.  It lets you lay out rules for how to
find filesystems and will mount and unmount them on demand.  It can
really simplify your life if you set it up correctly, as your rules
can be centralized and distributed via YP or rdist so server changes
don't kill you.

Rob T
--
Rob Thurlow, thurlow at convex.com or thurlow%convex.com at uxc.cso.uiuc.edu
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"This opinion was the only one available; I got here kind of late."