No NFS4 mount with kernel 5.11

[pixel24]

Hi@all,

Our home is on an NFS4 server. I am currently testing a few things with LM 20.2.
If I start LM 20.2 with kernel 5.4, I can mount the Home without any problems.

Code: Select all

mount -t nfs4 -o sec=krb5i srv01.gehr.local:/home /home

If I start the kernel 5.11, the same command leads to an error.

Code: Select all

root@pc002:~# mount -vvvv -t nfs4 -o sec=krb5i srv01.gehr.local:/home /home
mount.nfs4: timeout set for Wed Jul 14 12:51:08 2021
mount.nfs4: trying text-based options 'sec=krb5i,vers=4.2,addr=192.168.24.5,clientaddr=192.168.24.93'
mount.nfs4: mount(2): Permission denied
mount.nfs4: access denied by server while mounting srv01.gehr.local:/home

What could be the problem?

with best
pixel24

[pixel24]

I think I have a first clue. It seems to be the Kerberos ticket. Start:

Same machine
Same user

and display the Kerberos tickets, they are different. Depending on whether I start Kernel 5.4 or 5.11

Code: Select all

++ Kernel 5.4 ++

g.kopf@pc002:~$ klist
Ticketzwischenspeicher: FILE:/tmp/krb5cc_1049601150_k9TQia
Standard-Principal: g.kopf@GEHR.LOCAL

Valid starting       Expires              Service principal
14.07.2021 14:34:07  15.07.2021 00:34:07  krbtgt/GEHR.LOCAL@GEHR.LOCAL
	erneuern bis 15.07.2021 14:34:07
14.07.2021 14:34:09  15.07.2021 00:34:07  nfs/srv01.gehr.local@
	erneuern bis 15.07.2021 14:34:07
14.07.2021 14:34:09  15.07.2021 00:34:07  nfs/srv01.gehr.local@GEHR.LOCAL
	erneuern bis 15.07.2021 14:34:07


++ Kernel 5.11 ++

g.kopf@pc002:~$ klist
Ticketzwischenspeicher: FILE:/tmp/krb5cc_1049601150_IfoJUm
Standard-Principal: g.kopf@GEHR.LOCAL

Valid starting       Expires              Service principal
14.07.2021 14:36:21  15.07.2021 00:36:21  krbtgt/GEHR.LOCAL@GEHR.LOCAL
	erneuern bis 15.07.2021 14:36:21

[AndyMH]

Which explains why I couldn't see anything wrong with your fstab entry. When I mount my NAS using NFS I was using vers=3 in my options.

[rene]

When I earlier googled this I hit on https://bugs.debian.org/cgi-bin/bugrepo ... bug=979764 which is probably the relevant one. It's seemingly due to Debian (-derivatives) using an old version of rpc.gssd and there seems to be some sort of resolution in there but one seemingly involving Samba (why, oh, why) so I decided that you might be better of waiting for a different, possible first-hand experience as a reply. But see if that report's worth anything to you I guess.

[Moonstone Man]

I think I have a first clue. It seems to be the Kerberos ticket.

The link posted by rene and your statement that your "home is on an NFS4 server" begs the question of why you need kerberos on a home system. If you really must have the later kernel then I think your only choice is to remove kerberos. Other than that, using the lower version kernel and waiting to see if it gets fixed is about it.

[AndyMH]

then I think your only choice is to remove kerberos.

Which is why, when I connected with NFS, I used vers=3 to avoid kerberos.

[rene]

Don't need to use Kerberos with NFSv4 either. I.e., simple type "nfs" between two Mint 20 systems will use NFSv4 fully automagically and with from a user standpoint no difference from NFSv3. Kerberos is something you have to explicitly set up and with such not being fully trivial I believe we may assume OP has/had a reason for it.

[pixel24]

I will have a look at the bug report. The server (Univention) is not at home but in the company. NFS3 or without Kerberos is not an option.

[Moonstone Man]

The server (Univention) is not at home but in the company. NFS3 or without Kerberos is not an option.

That makes sense.

[Moonstone Man]

then I think your only choice is to remove kerberos.

Which is why, when I connected with NFS, I used vers=3 to avoid kerberos.

Odd. I run nfs4 and don't use kerberos.