How Efficient/Stable are the am-utils?

Steve Baum asks: "I'm thinking of replacing a current tangle of NFS cross-mounted disks with the am-utils system, which maintains a cache of mounted filesystems that are demand-mounted when first referenced and unmounted after a period of inactivity. I was wondering if anyone had used this system in a moderately large (40-50 disks on 10-15 machines) environment and, if so, how efficient and stable they'd found it to be."

Not very good

[Anonymous Coward]

I used to use them on my combined network of Sun Ultra2s, Linux-based PCs, and the occasional older SGI. We tried to switch to am-utils to cut down on the network connections and excess traffic created by buggy NFS implementations (eg, those found in Linux kernel-based implementations (the two user-land implementations we later tried were fine, i fogget what either of them is called))

At any rate, am-utils failed to properly unmount shares on the SGI and Linux machines, which lead to threadlocks on Ultrix and file-descriptor shortages (followed shortly by VM crashes). Needless to say, this was dropped, and we switched to a combination of WebDAV and shared RAID arrays (distributed clustering and NAS systems were also evaluated and later dropped from consideration, mostly due to cost).

Advice to you? am-utils is not all it seems. Dont forget that NFS is not the only way to get remote file access. Re-evaluate what you need. Sometimes, things as simple as GNOME VFS or Emacs's efs are enough. Otherwise, look at the things I mentioned above.

-rick

AFS anyone

[FSK]

Have you thought about switching to AFS? I relize this is slightly off-topic but AFS (IMHO) is a much better solution to NFS.

Re:AFS anyone

[O]

Hell yeah
OpenAFS [openafs.org] baby!

Re:AFS anyone

[redmondraper]

That is - if you've got months to waste on trying to configure it. Barely any good documentation out there...

Pretty satisfactory

[psmith]

Our environment in my department at Purdue uses am-utils extensively for our NFS handling. Home directories, group file repositories, and shared software installation.

Am-utils is well suited to what we use it for (or perhaps what we do is determined around what am-utils can do, hmm.) Some examples of what we use it for:

• Home directories. Home directories come from either of two central fileservers (with the RAID), or if the user's a disk hog, their home directory can be served from their workstation. Amd lets us just forget where something is physically stored and let amd deal with finding /home/psmith. Our group file storage areas work the same way.
• Shared software installation. Rather than install matlab, OpenPBS, PVM, MPICH, etc. on every system, am-utils lets us install software in a common amd mountpoint, and amd handles the behind-the-scenes stuff to make sure it mounts the version for the proper architecture. Basically, it maps people's requests for /package/matlab to fileserver:/net/fileserver/package/matlab/${os}

Add in the cross-platform-ness (we mix SunOS, Solaris, FreeBSD, Linux, and AIX in our am-utils environment), and I'm most pleased with it.

Granted, I'm sure you know of its benefits, but as to its reliability and efficiency, I've got no gripes. Any speed/flakiness issues I've encountered are most likely issues with the underlying NFS implementations, and those have really been pretty few and far between.

Our setup

[JimMcCusker]

Our department in our company has about 30 Solaris machines with about 15 Linux (Mandrake and Red Hat) machines set up with NIS, NFS, and auto-fs (on linux) and automount on Solaris. We have had this set up for longer than I've been there (~3 years). I know of no problems with this system. Using this system allows us to have centralized home directories by default and allow some users (myself included) to have local home directories, because some of us are developing very IO-intensive applications. We are all able to log into any other machine with no trouble, and am-utils has been essential to our linux setup and has only given us one problem: one fellow, who has a very unconventional home directory setup, has managed to make autofs 4.0.0 barf consistently on it. The 3.x series has no trouble.