LinuxQuestions.org - NFS killing me, (can't read superblock)

- Linux - Networking (https://www.linuxquestions.org/questions/linux-networking-3/)

- - NFS killing me, (can't read superblock) (https://www.linuxquestions.org/questions/linux-networking-3/nfs-killing-me-cant-read-superblock-330597/)

NFS killing me, (can't read superblock)

Hey guys,

Problem

i don't know why, but NFS suddenly stop working yesterday night, i wanted to unmount my shared USB HDD so i stoped manually nfs-kernel-server, and portmap, after i plug it (even after server-client restarting) i keep getting the message

Code:

wael@nasreddine:~$ sudo mount /media/WAEL_FAT/

mount: 192.168.3.2:/media/WAEL_FAT: can't read superblock

wael@nasreddine:~$ sudo mount -t nfs 192.168.3.2:/ /media/SERVER/

mount: 192.168.3.2:/: can't read superblock

Information
client:

Code:

wael@nasreddine:~$ rpcinfo -p 192.168.3.2

  program vers proto  port

    100000    2  tcp    111  portmapper

    100000    2  udp    111  portmapper

    100003    2  udp  2049  nfs

    100003    3  udp  2049  nfs

    100003    4  udp  2049  nfs

    100003    2  tcp  2049  nfs

    100003    3  tcp  2049  nfs

    100003    4  tcp  2049  nfs

    100021    1  udp  32770  nlockmgr

    100021    3  udp  32770  nlockmgr

    100021    4  udp  32770  nlockmgr

    100021    1  tcp  32768  nlockmgr

    100021    3  tcp  32768  nlockmgr

    100021    4  tcp  32768  nlockmgr

    100005    1  udp    865  mountd

    100005    1  tcp    868  mountd

    100005    2  udp    865  mountd

    100005    2  tcp    868  mountd

    100005    3  udp    865  mountd

    100005    3  tcp    868  mountd

    100024    1  udp    603  status

    100024    1  tcp    606  status

wael@nasreddine:~$

wael@nasreddine:~$ ps -edf |grep po

daemon    6543    1  0 13:51 ?        00:00:00 /sbin/portmap

wael@nasreddine:~$ cat /etc/fstab

192.168.3.2:/media/WAEL_FAT    /media/WAEL_FAT nfs    rw,hard,intr,noauto    0      0

192.168.3.2:/  /media/SERVER  nfs    rw,hard,noauto  0      0

192.168.3.2:/media/REDOUANE    /media/REDOUANE nfs    rw,hard,intr,noauto    0      0

wael@nasreddine:~$ showmount -e 192.168.3.2

Export list for 192.168.3.2:

/              192.168.2.0/255.255.255.0,192.168.1.0/255.255.255.0

/media/REDOUANE 192.168.2.0/255.255.255.0,192.168.1.0/255.255.255.0

/media/WAEL_FAT 192.168.1.0/255.255.255.0,server.local,192.168.2.0/255.255.255.0

server:

Code:

server:/etc# cat /etc/exports

/      192.168.1.0/255.255.255.0(rw,sync) 192.168.2.0/255.255.255.0(rw,sync)



/media/WAEL_FAT 192.168.1.0/255.255.255.0(rw,sync) 192.168.2.0/255.255.255.0(rw,sync)



/media/REDOUANE 192.168.1.0/255.255.255.0(rw,sync) 192.168.2.0/255.255.255.0(rw,sync)

server:/etc# cat hosts.allow

portmap: 192.168.2.0/255.255.255.0 192.168.1.0/255.255.255.0

mountd: 192.168.2.0/255.255.255.0 192.168.1.0/255.255.255.0

rquotad: 192.168.2.0/255.255.255.0 192.168.1.0/255.255.255.0

statd: 192.168.2.0/255.255.255.0 192.168.1.0/255.255.255.0

server:/etc# cat hosts.deny

portmap: ALL

mountd: ALL

rquotad: ALL

statd: ALL

server:/etc# cat fstab

### adding external Hard disks

/dev/sda2      /media/WAEL_FAT vfat    defaults,auto,uid=1000,gid=1000,iocharset=utf8  0      0

server:/etc# ls /media/WAEL_FAT/

AuthorizationForm.doc  ClickHere.exe  ClickHere.ini  CRAZY FROG Axel F .wma  gdiplus.dll  mmc  Redouane_merci wael  server.zip  wael  yvon

Question
what's going on, i tried almost everything, i can't get into the HDD using NFS :o

Thanks in advance

Did you stop NFS before umounting your USB thumbdrive?

I found out that if, for some reason, my server umounts a drive before stopping NFS, things go to hell real quick. I have to umount the drives on the NFS clients, then stop the NFS service on the server, then umount the drives on the server, then reverse the process. If I don't, my computer gets very angry, very quickly.

indeed i forget to unmount it from the client before, but i did stop NFS server, samba Server and unmount the HDD to unplug it safely,
but i didn't unmount it from the client before
so any suggestions please???

The only suggestion I can offer is to kill NFS on both machines, then mount the drive on your server, start the nfs server apps, then start the nfs client apps on your client computer, then try to mount the drive.

If that doesn't work, you can always try *shudder* a reboot as a last resort to kill anything that's lurking.

oh i reboot serval times both server and client
and also i apt-get remove --purge nfs-kernel-server pormap nfs-common and then apt-get install nfs-kernel-server portmap nfs-common on both server and client (client without the nfs-kernel-server package) serval times
same result :'(

Well, I'm out of ideas then. :( All that stuff always works for me.

So consider this a type of bump.

Well i wuld suggest you to stop all the nfs services then reconfigure your file do all the stuff you did in the past and then again restart the service.

Also this looks weird but I have seen this times that if you get such messages in GUI switch to command mode you wont get them and vice versa

it's realy killing me because as i mentioned in the first post, i tried everything, reconfigure, reboot, reinstall, of course not formatting yet,
it happened to me once before but i was preparing the server for a format and distribution change (from ubuntu to debian) so i didn't get deep in it, after a format it worked but i can't format the server each time it stops working, i have sites on ther server can't turn it off whenever i want
so a help is really appreciated, i'll take above advices and i'll proceed now to try to re-reconfigure and re-reinstall to see if any difference

thx for reply guys

is it normal that a FAT HDD cannot be scanned via fsck??

Code:

server:~# fsck /dev/sdb

fsck 1.37 (21-Mar-2005)

e2fsck 1.37 (21-Mar-2005)

Couldn't find ext2 superblock, trying backup blocks...

fsck.ext2: Bad magic number in super-block while trying to open /dev/sdb



The superblock could not be read or does not describe a correct ext2

filesystem.  If the device is valid and it really contains an ext2

filesystem (and not swap or ufs or something else), then the superblock

is corrupt, and you might try running e2fsck with an alternate superblock:

    e2fsck -b 8193 <device>

Code:

server:~# e2fsck -b 8193 /dev/sdb

e2fsck 1.37 (21-Mar-2005)

e2fsck: Bad magic number in super-block while trying to open /dev/sdb



The superblock could not be read or does not describe a correct ext2

filesystem.  If the device is valid and it really contains an ext2

filesystem (and not swap or ufs or something else), then the superblock

is corrupt, and you might try running e2fsck with an alternate superblock:

    e2fsck -b 8193 <device>

Have u given an entry for the device to auto mount if yes remove it or see the fstab file whether it has an entry or not

yes, it has default so it will be auto mounted
/dev/sdb2 /media/WAEL_FAT vfat defaults,auto,uid=1000,gid=1000,iocharset=utf8 0 0

remove that it will be solved

i tried it didn't work, i'll try to reboot both server and client and retry

nope it didn't work :(