[SOLVED] NFSv4: "Device is busy"

hermes · 2012-10-20 21:27:47

This is a weird issue, because it happened just today, having been using nfs for years, and because it is triggered by trying to access the "root" filesystem on the server (the one with fsid=0).
I use autofs client side. This is the /etc/exports from my server:

/srv/nfs4		192.168.1.0/24(rw,fsid=0,sync,no_subtree_check,no_root_squash)
/srv/nfs4/storage	192.168.1.0/24(rw,sync,no_subtree_check,no_root_squash)

"storage" gets correctly mounted, since I can access all of its subdirectories without any problems, but here's what happens if I issue a simple ls:

$ ls /net/myhost/srv/nfs4/storage
ls: cannot access /net/myhost/srv/nfs4/storage: Device or resource busy
storage

After that, the nfs server, which is up and reachable via ssh, isn't accessible anymore, no matter what I try to do.

$ fuser /net/myhost/srv/nfs4/storage
Cannot stat /net/myhost/srv/nfs4/storage: Device or resource busy

$ lsof /net/myhost/srv/nfs4/storage
lsof: status error on /net/myhost/srv/nfs4/storage: Device or resource busy

$ umount -f /net/myhost/srv/nfs4/storage
umount.nfs: /net/myhost/srv/nfs4/storage: device is busy

Very inexpressive messages...
I can't do anything: unmounting, unloading modules... Reboot hangs, so I have to force it.

There must be something I'm missing, but I'm out of clues.

Last edited by hermes (2012-10-23 08:52:06)

teletrabi · 2012-10-21 09:42:47

I had the same issue yesterday when following the guide from wiki: https://wiki.archlinux.org/index.php/Au … ork_mounts
So /srv/nfs4 gets mounted well - but the drive is busy, when you try to mount it for the 2nd time with /srv/nfs4/storage.

I resolved it temporarily by deleting "/srv/nfs4" from /etc/exports and setting fsid=0 to "/srv/nfs4/storage".

hermes · 2012-10-21 10:43:59

I followed the Gentoo wiki and it's working. If it proves to be reliable over time, I'll mark the thread as solved.

hermes · 2012-10-23 08:51:44

Ok, it looks like it was an autofs problem and. Like I said, the Gentoo wiki has been very helpful and in my simple setup the instructions there provided solved the issue. Since I haven't had any problems in a couple of days, I'll mark the thread as solved.

lgbr · 2012-10-25 21:23:25

I had the 'device or resource is busy' issue as well. In my case, I didn't have 'fsid=0' in the exportfs for either directory, and I fixed it by adding 'fsid=0' to the subdirectory.

Arch Linux

#1 2012-10-20 21:27:47

[SOLVED] NFSv4: "Device is busy"

#2 2012-10-21 09:42:47

Re: [SOLVED] NFSv4: "Device is busy"

#3 2012-10-21 10:43:59

Re: [SOLVED] NFSv4: "Device is busy"

#4 2012-10-23 08:51:44

Re: [SOLVED] NFSv4: "Device is busy"

#5 2012-10-25 21:23:25

Re: [SOLVED] NFSv4: "Device is busy"

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