Helpdesk : AFS
These are frequently asked about AFS, that might help you
resolve your problem. If you cannot find an answer to your
question here, or in the
guided tours, then use the
and we will try to assist you as soon as possible.
Why can't I access the AFS filesystem?
Usually you authenticate yourself when you login to a PDC machine.
The only exception is when you login from a machine in another
Kerberos realm (site where Kerberos is used) that is "known" by the
As a side effect of this authentication you will get what is called a
ticket and an AFS token. The kerberos ticket is used
(automatically, you dont have to do anything) to request services
like the right to rlogin to another machine without password, the
right to retrieve mail from the mail server, etc. The AFS token is
needed to get access to the file system. In some circumstances these
functions don't seem to work. Let's examine some common problems:
- You cannot read/write files in your home directory anymore
This is typically caused by tokens expiring and it is necessary
to renew them. This is done with the command kauth.
- No write access after rlogin to another PDC machine
This happens because rlogin doesn't propagate tickets or tokens
to the remote machine. Assume your keyboard is connected to
a machine called `workplace' and our machine called strindberg.
You should first give yourself a ticket on the machine you want to
rlogin to (strindberg in this case) like this
and then get AFS tokens on the remote machine like this
- workplace>kauth -h strindberg.pdc.kth.se
You can list your tickets and tokens with the commands
- strindberg> klist
- strindberg> tokens
Can I authenticate to AFS at PDC from another site?
Yes, but it isn't automatic. Please get in touch
with us is this is of interest to you. Note that this is of interest
only if the other site has AFS installed. Some do, but most don't,
because AFS usually costs money, however...
Note that you do not need to have AFS installed at your site to use the computers at
How do I extend tickets or tokens for my batch job?
If you run Easy the tokens for AFS are copied out
of the kernel, where they are stored, and saved into
a file at submit time . You can not extend
the lifetime of the tickets/tokens of a job when it is
You can read about how to create tickets with long lifetimes at
the Kerberos Guided Tour.
If you couldn't find your problem listed above, you can fill out this
describing your problem in detail, and we will try to address it as soon as possible.
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