If you use a computer in a computer cluster workstation your UNIX home directory is in AFS, not on the machine you happen to be logged into. AFS thinks of network-accessible disk space as a collection of volumes, which are contained, easy to manage, quota controlled chunks of data. It doesn't matter what AFS server your volume is on: regardless of where it is physically located, your volume will appear in a consistent place in the AFS file hierarchy. That place is:
Where "y" and "o" are the first two letters of your login SUNet ID. For example, /afs/ir/users/j/d/jdoe. Knowing this -- that your Unix account is actually located in AFS disk space, not on the computer you're logged into -- can sometimes help you figure out why you can't log in.
Understanding Login Errors
Very occasionally, either the hardware your AFS volume is located on fails, or the machine from which you are trying to access AFS can't see the file system. Below are some diagnostics to tell which of these conditions have occurred. Neither of them means that your data has been lost because, even in the worst case, your volume is backed up every night.
Regardless of whether you can't access AFS because the machine you are using can't see it, or because the AFS server that holds your volume is down, you'll probably get the same mesage. You'll get a note when you try to login that says your directory "/afs/ir/users/u/s/username" can not be found, and that the system is logging you in with a home directory of "/". You won't be able to access your files or your email if this happens. However, it does not mean that your account has been deleted or that your files are permanently lost.
- Determining if Your Server is Down
The first thing you should do is try to access your user volume from a different machine. If you can get to your volume from a different machine, please file a HelpSU ticket saying that there's a problem with the AFS client on the machine you first tried to log into.
If you still can't get in, your AFS server may be having problems. The first thing you should do is figure out what AFS server you're on. Use this command:
vos examine user.<username>
The last line of what's returned will look like:
server afssvr18.Stanford.EDU partition /vicepb RW Site
Which means, in this case, that your user volume would be on "afssvr18". To find out if any servers are down, type:
If everything is running normally, you will get back the message "All servers are running." Otherwise, you should get a list of which servers are currently unreachable by the machine you've logged into.
Please file a HelpSU ticket with all of this information.