opinion - loopback fs or symbolic links
Folks,
I need an opinion on what you use to redirect data sources and create space for users: loopback filesystems or symbolic links. I am new to loopback filsystems (lofs) - are there any drawbacks to using them? I have always used symlinks for redirects and to move data off of filesystems due to space issues. I have recently been on a machine that uses lofs extensively - it initially was a source of considerable confusion - but being new to sun, I wanted a concensus on it's use. Thanks...
[509 byte] By [
mvmurphya] at [2007-11-26 22:07:24]
# 1
I just wasted a few hours of time because some previous admin used a loopback mount instead of a softlink. The reason is that I was doing a bare metal restore, but to a different architecture, so I could not restore the OS exactly. I installed a fresh OS, installed everything else to an alternate directory, and then tried to move the app back to the main OS directory tree.
The soft links required for the app to work would have been restored from tape and seen easily, but the loopback was buried in the old vfstab, which I had restored to the alternate directory, so it took a bit of luck and premonition to find it.
Note to programmers: If your distro requires either to function properly, you are incompetent. If your Solaris app isn't packagified, you are lazy.
Regognizing that a lot of progrmmers are lazy and incompetent, as a sysadmin you will occasionally be presented with this choice - I would always choose softlinks for the reason above. There is no performance penalty.
# 2
A problem exists for some packages that check their storage location like '/usr/local'.
In some cases the packaging tools will remove the symlink and create a new directory, probably on a filesystem you didn't want. Loopback mounts aren't touched in this manner.
--
Darren
