optional mounts in fstab?

[Bill Davidsen]

I have a system used for backups, and when it boots it *may* have any or all of 
a number of small hot-swap RAID storage units connected by eSATA. Ideally I 
would like the system to fsck and mount these when present, using the UUID= 
option in fstab. There's a problem. If the units are not connected the system 
tried to fsck them anyway, considers them missing, and doesn't complete boot. 
Defining the mount as "noauto" doesn't help, the boot still tries to do the 
fsck, and still fails. Moreover, I really want the unit mounted if present.

Next I set the fsck field to 0, which does prevent unwanted fsck, but also 
doesn't fsck even when the unit is attached and detected. More "doesn't do what 
I want" behavior.

I might be able to hack the behavior I want into udev, but it would be a real 
non-standard behavior there.

I thought the 'nofail' option would solve the problem, but that appears to be a 
very recent option, and not in RHEL running on this server.

Any thoughts gratefully accepted, we try to keep vital infrastructure running on 
RHEL rather than Fedora, for obvious reasons of stability and avoiding having to 
upgrade and re-certify every six months.

-- 
Bill Davidsen <davidsen at tmr.com>
   We are not out of the woods yet, but we know the direction and have
taken the first step. The steps are many, but finite in number, and if
we persevere we will reach our destination.  -me, 2010