To enable access to AFS for systems without (stable) AFS clients, I’ve been interested in exporting my cell somehow or another. The intent would be to have a local machine or VM serving up the AFS share in a way which preserves its POSIX-like interface. I’ve heard that others are using unfs3 to do this, and so I tested it out and took some notes.

Goals:

1. Share should “work” well enough to keep a home directory in

Concessions:

1. Share may be potentially accessible by only one client at once
2. Share should be accessible by many OSs somehow or another. (9P? NFS? webdav? sshfs?)
3. Performance may be particularly limited
4. Permissions/ACLs may be simplified greatly
5. May require keytabs/k5start to keep it going

Using unfs3

Tried this out using unfs3 as found at your-file-system’s unfs3 github fork.

Steps to get this running again:

• I had to add #include <afs/stds.h> in afssupport.c to get it to build on Debian 8. Otherwise, afs_uint32 was undefined.
• Create a small afs_exports, something like:

/afs/tcreech.com testclient(rw)

• Run as an unprivileged user, holding the tokens that you want to effectively export. This will register mount/nfs with RPC. (Note that you may not need to specify the ports with -n and -m.)

./unfsd -s -u -t -d -e $PWD/afs_exports -n 8888 -m 8889

• You should now be able to mount this in the usual way from the specified client:

mount -o vers=3,soft server:/afs/tcreech.com /mnt/unfstest

How well does it work?

Works:

1. Accessible to Linux (half-hearted yay…)
2. Wrote this page via NFS-exported AFS

Doesn’t works:

1. running “file” on a bunch of ISOs (server allegedly stops responding)
2. tar xf tmux-2.0.tar.gz; IO errors

I am sad.

Using sshfs

OSs which support sshfs in a reasonable capacity which also do not have stable OpenAFS clients:

• FreeBSD (via fuse)
• NetBSD (via puffs)
• DragonFlyBSD? (via puffs supposedly, but I have not tested)
• plan9 sorta maybe (via ssh and remote u9fs)