On Wed, 2010-06-23 at 11:32 -0700, Chris Quenelle wrote:
> Thanks for your time guys!
>
> It turns out it's not a general bug. I was just applying
> a pessimistic interpretation without checking.
>
> After more testing, it turns out it's just problem
> on one machine, for two mount points under one
> host alias.
>
> I'm interested in knowing more about how I could
> debug the situation without just rebooting and
> hoping it doesn't happen again.
>
> Here's my scenario:
>
> I have three exported filesystems.
> I can use three host aliases to refer to my own machine.
> (carabas, carabas.sfbay, carabas.sfbay.sun.com)
>
> /etc/hosts says:
> [IP addr] carabas.sfbay.sun.com carabas
>
>
> All filesystems work under all /net/foo aliases
> except two of them hang when accessed via one
> of the host aliases.
Are you sure the address lookup is returning what you think it does?
What's in /etc/host.conf?
>
> % showmount -e localhost
> Export list for localhost:
> /export/home3 *
> /export/home2 *
> /export/home1 *
>
>
> % df -kl
> Filesystem 1K-blocks Used Available Use% Mounted on
> /dev/sda2 69575344 3408900 66166444 5% /
> udev 8222568 148 8222420 1% /dev
> /dev/sdb1 71671728 26507132 45164596 37% /export/home1
> /dev/sdc1 71671728 8545196 63126532 12% /export/home2
> /dev/sdd1 71671728 5375672 66296056 8% /export/home3
> /export/home1 71671728 26507128 45164600 37%
> /net/carabas/export/home1
> /export/home2 71671728 8545196 63126532 12%
> /net/carabas.sfbay/export/home2
> /export/home1 71671728 26507128 45164600 37%
> /net/carabas.sfbay/export/home1
> /export/home3 71671728 5375672 66296056 8%
> /net/carabas.sfbay/export/home3
> /export/home1 71671728 26507128 45164600 37%
> /net/carabas.sfbay.sun.com/export/home1
> /export/home2 71671728 8545196 63126532 12%
> /net/carabas.sfbay.sun.com/export/home2
> /export/home3 71671728 5375672 66296056 8%
> /net/carabas.sfbay.sun.com/export/home3
>
>
> % strace ls /net/carabas/export/home2
> ...
> ...
> mmap(NULL, 217016, PROT_READ, MAP_SHARED, 4, 0) = 0x2b2388370000
> close(4) = 0
> close(3) = 0
> open("/net/carabas/export/home2", O_RDONLY|O_NONBLOCK|O_DIRECTORY <unfinished
> ...>
What does a ps listing give you when it is blocked?
Any mount.nfs processes?
That's sign that automount thinks that the mount isn't local and is
probably trying to mount from a possibly non-existent ip address.
>
> I hit ctrl-C when the ls command hangs. Above is the tail of the strace
> output.
> It doesn't tell you much, the interesting stuff happens in the automounter.
>
> Is there a error log file for the automounter that is enabled by default?
> Is there an easy recipe for restarting the automounter with debugging output
> on?
You need to ensure that debug logging is being recorded in syslog.
Ensure you are sending daemon.* somewhere.
Then
automount -l debug /net
will start the debug logging and
automount -l err /net
will set it back to no logging.
That is depending on the version of autofs you are using.
If you don't see this option in the automount(8) man page you don't have
this option and all you can do is enable debug logging in the
configuration.
Ian
_______________________________________________
autofs mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/autofs
