[15489] in athena10
Re: Debathena Fails to load AFS kernel modules
daemon@ATHENA.MIT.EDU (Benjamin Kaduk)
Wed Feb 28 22:02:29 2018
Date: Wed, 28 Feb 2018 21:01:50 -0600
From: Benjamin Kaduk <kaduk@mit.edu>
To: Anne Collin <acollin@mit.edu>
Cc: debathena <debathena@mit.edu>
Message-ID: <20180301030149.GO50954@kduck.kaduk.org>
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Hi Anne,
I'm not 100% sure I'm understanding the description, but it sounds
like the user's Kerberos and AFS credentials (ticket and token,
respectively) are expiring overnight, and then the desktop
environment is unable to read or write some of its files in the
user's home directory. Depending on the details of the situation,
it may make sense to use a local user account instead of the
Athena account for this sort of long-running job, or use a script to
periodically renew these credentials, or set up the job to run in a
minimal (non-GUI) session with its own credentials, or some number
of other options.
The simplest renewal script would be something like
# This kinit prompts for a password
kinit -l1d -r7d
/bin/sh -c 'while true; do kinit -R; sleep 1; aklog; sleep 3600; done'
but there are of course many variations possible, especially if it
is desired to have some form of advance notice before the 7-day
renewal timer runs out. The current Kerberos and AFS credentials
can be listed using the `klist` and `tokens` commands, respectively.
Hope this helps,
Ben
On Wed, Feb 28, 2018 at 02:37:30PM -0500, Anne Collin wrote:
> Hi again Ben,
>
> I have a somewhat related question; is there a way to prevent the login of a user to time-out on our machine? What happens is that I check in the morning results that have been running during the night, but I’m being told that my authentification expired, and then when I try to do something the screen freezes. The only solution I have is to do a manual reboot, which I’m sure is not great for the system. I didn’t manage to find anything online in the Debathena docs about this.
>
> Best,
> Anne
>
> > On 28 Feb 2018, at 10:15, Anne Collin <acollin@mit.edu> wrote:
> >
> > Hi Ben,
> >
> > Thanks a lot for tracking this down! I ended up reinstalling Ubuntu and Debathena from scratch and openAFS now works, but I wasn’t sure if I could upgrade to 16.04 as it didn’t seem to be supported by Debathena. So your answer is useful in that 1) now I know that I can and 2) I was afraid it would happen again.
> >
> > It’s true that it started getting messed up after upgrades that were suggested around the time of the « spectre » publicity.
> >
> > Best,
> > Anne
> >
> >> Am 27.02.2018 um 21:16 schrieb Benjamin Kaduk <kaduk@mit.edu>:
> >>
> >> [re-adding debathena@mit.edu to the cc list]
> >>
> >> Hi Anne,
> >>
> >> Thanks for the data. It looks like you're running the Ubuntu
> >> "hardware enablement" kernel with the 14.04.5 release, as opposed to
> >> the older linux kernel series that shipped with the original 14.04
> >> release. With some help from another developer, we spotted a
> >> potential issue with this setup, in that the kernel you're running
> >> is compiled using a compiler feature called "retpoline", that was
> >> introduced as a partial mitgiation for the "spectre" vulnerabilities
> >> that have been in the news recently. This changes the contract for
> >> interactions between kernel modules such as the one from OpenAFS,
> >> and the main kernel, so that the kernel module in question would
> >> need to use the same compiler as the main kernel. Unfortunately,
> >> the updated compiler does not appear to be readily available on your
> >> system, and so (if our hypothesis is right), the mismatch would
> >> prevent openafs from working.
> >>
> >> We could get one more data point to try to confirm if this is the
> >> case, via:
> >>
> >> sudo dmesg | grep openafs
> >>
> >> In terms of possible workarounds, if you do not actually need the
> >> "nardware enablement" kernel for the particular hardware in
> >> question, you could try to downgrade to an older kernel; otherwise,
> >> the simplest solution might be to upgrade the machine to a newer
> >> Ubuntu release (e.g., 16.04 "Xenial", the source of the "hardware
> >> enablement" kernel; the requisite compiler looks to be present on
> >> Xenial systems).
> >>
> >> This is all pretty complicated and confusing, so please ask for
> >> clarification as needed.
> >>
> >> -Ben
> >>
> >>> On Mon, Feb 26, 2018 at 04:07:46PM -0500, Anne Collin wrote:
> >>> Sorry, the actual response to “lsb_release -a” is
> >>>
> >>> “No LSB modules are available.
> >>> Distributor ID: Ubuntu
> >>> Description: Ubuntu 14.04.5 LTS
> >>> Release: 14.04
> >>> Codename: trusty”
> >>>
> >>> Anne
> >>>
> >>>> On 26 Feb 2018, at 14:31, Anne Collin <acollin@mit.edu> wrote:
> >>>>
> >>>> Hi Ben,
> >>>>
> >>>> Thanks for the quick response, I'm attaching the screenshot of the terminal.
> >>>>
> >>>>
> >>>> ________________________________________
> >>>> De : Benjamin Kaduk [kaduk@mit.edu]
> >>>> Envoyé : lundi 26 février 2018 13:53
> >>>> À : Anne Collin
> >>>> Cc : debathena
> >>>> Objet : Re: Debathena Fails to load AFS kernel modules
> >>>>
> >>>> Hi Anne,
> >>>>
> >>>>> On Mon, Feb 26, 2018 at 01:50:03PM -0500, Anne Collin wrote:
> >>>>> Hi,
> >>>>>
> >>>>> For some reason I am not able to access AFS MIT user accounts (not just mine, several MIT students’) on our lab Debathena machine (used to work fine until last week). I logged with the local admin account, and tried to troubleshoot with these instructions http://kb.mit.edu/confluence/display/istcontrib/Troubleshooting+Debathena+installation <https://master.mailbutler.io/redirect/90F34E00-60F7-403B-BBCB-CAD61795EB13>, but when I try to restart openafs-client, I get the error
> >>>>> “Starting AFS services:modprobe: ERROR: could not insert ‘opens’: Exec format error
> >>>>>
> >>>>> Failed to load AFS kernel module, not starting AFS”
> >>>>>
> >>>>> Do you have any advice on what I should do? I’m even ready to reinstall Debathena, but I didn’t find any documentation online on how to do that.
> >>>>
> >>>> The OpenAFS packages used by Debathena are maintained as part of
> >>>> Debian and Ubuntu, so in general issues seen with them may also be
> >>>> present on non-Debathena machines. To help us understand what's
> >>>> going on, could you provide the output of the following commands?
> >>>>
> >>>> uname -a
> >>>>
> >>>> lsb_release -a
> >>>>
> >>>> dpkg-query -W openafs-client
> >>>>
> >>>> Thanks,
> >>>>
> >>>> Ben
> >>>> <Screenshot from 2018-02-26 14:30:25.png>
> >>>
> >>
> >>
> >>
>
