/etc/fstab overwritten Please help to recover

sagar666 · 08-31-2015, 08:15 AM

Hi,

By mistakenly i overwritten /etc/fstab like below

echo "bigfoot:/t6_dump /t6_dump nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0" > /etc/fstab

instead of using >> i have used it > It has 50 servers all got overwritten with above entry and i don't have backup.

[root@vncin47 etc]# cat /proc/mounts
rootfs / rootfs rw 0 0
/dev/root / ext3 rw,data=ordered 0 0
/dev /dev tmpfs rw 0 0
/proc /proc proc rw 0 0
/sys /sys sysfs rw 0 0
/proc/bus/usb /proc/bus/usb usbfs rw 0 0
devpts /dev/pts devpts rw 0 0
/dev/sda1 /boot ext3 rw,data=ordered 0 0
tmpfs /dev/shm tmpfs rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw 0 0
bigfoot:/ecad /ecad nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd1 /pd1 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd3 /pd3 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd5 /pd5 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd6 /pd6 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd8 /pd8 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/dv3 /dv3 nfs rw,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
asteroid:/dv4 /dv4 nfs rw,vers=3,rsize=65536,wsize=65536,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=asteroid 0 0
asteroid:/dv5 /dv5 nfs rw,vers=3,rsize=65536,wsize=65536,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=asteroid 0 0
bigfoot:/dv6 /dv6 nfs rw,vers=3,rsize=65536,wsize=65536,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
/etc/auto.misc /misc autofs rw,fd=6,pgrp=2822,timeout=300,minproto=5,maxproto=5,indirect 0 0
-hosts /net autofs rw,fd=12,pgrp=2822,timeout=300,minproto=5,maxproto=5,indirect 0 0
auto.home /home autofs rw,fd=18,pgrp=2822,timeout=60,minproto=5,maxproto=5,indirect 0 0
10.193.182.150:/hw_home/murali /home/murali nfs rw,vers=3,rsize=1048576,wsize=1048576,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0
bigfoot:/pd7 /pd7 nfs ro,sync,vers=3,rsize=262144,wsize=262144,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=bigfoot 0 0

I got nfs share mount point info and but i did not get system mount point info

If any one server reboots it wont boot. Is there any way i can restore before server reboot? Please help. Immediate help is highly appreciated.

wildwizard · 08-31-2015, 08:43 AM

First "cat /proc/mounts > /etc/fstab"

It wont be pretty but it should let it boot, actually it will have an incorrect / partition as yours is showing /dev/root (fix it manually)

You'll have to clean it up from that depending on your distro's startup files some of those mounts will be done directly.

sagar666 · 08-31-2015, 08:50 AM

Thanks for the quick help and its RHEL 5.7. Please help me how exactly need to be modify for root filesystem.

blkid shows
/dev/sr0: LABEL="RHEL/5.7 x86_64 DVD" TYPE="iso9660"
/dev/sda5: LABEL="/share" UUID="4f1dbed0-3ab9-4ec1-b6e7-3db6a1974e30" TYPE="ext3"
/dev/sda3: LABEL="SWAP-sda3" TYPE="swap"
/dev/sda2: LABEL="/" UUID="76635581-564e-42b3-a596-2d0d46d1fb13" TYPE="ext3"
/dev/sda1: LABEL="/boot" UUID="097e37c6-0113-441f-8c5e-3abcdcc5fcf5" TYPE="ext3"

/dev/sda2: LABEL="/" UUID="76635581-564e-42b3-a596-2d0d46d1fb13" TYPE="ext3" is root right?

michaelk · 08-31-2015, 08:53 AM

Post the output of the command
/sbin/blkid

sagar666 · 08-31-2015, 08:59 AM

blkid shows
/dev/sr0: LABEL="RHEL/5.7 x86_64 DVD" TYPE="iso9660"
/dev/sda5: LABEL="/share" UUID="4f1dbed0-3ab9-4ec1-b6e7-3db6a1974e30" TYPE="ext3"
/dev/sda3: LABEL="SWAP-sda3" TYPE="swap"
/dev/sda2: LABEL="/" UUID="76635581-564e-42b3-a596-2d0d46d1fb13" TYPE="ext3"
/dev/sda1: LABEL="/boot" UUID="097e37c6-0113-441f-8c5e-3abcdcc5fcf5" TYPE="ext3"

michaelk · 08-31-2015, 09:22 AM

No backups?

I would save the output of /proc/mounts to a file but not /etc/fstab. I do not see the /share mounted but you can add it. I can not guarantee it matches the original minus the nfs mounts but should boot...

Code:

LABEL=/                 /                       ext3    rw                      0 0 
LABEL=/boot             /boot                   ext3    rw,data=ordered         0 0 
/LABEL=SWAP-sda3        swap                    swap    defaults                0 0
tmpfs                   /dev/shm                tmpfs   defaults                0 0
devpts                  /dev/pts                devpts  defaults                0 0
sysfs                   /sys                    sysfs   defaults                0 0
proc                    /proc                   proc    defaults                0 0

sagar666 · 08-31-2015, 10:17 AM

thanks a lot michaelk and No backup,

I have changed to /etc/fstab/ like below. anything wrong in below file or I need to put format like above you mentioned?

/dev/mapper/VolGroup00-LogVol00 / ext3 rw 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
devpts /dev/pts devpts rw,gid=5,mode=620 0 0
/dev/sda1 /boot ext3 rw 0 0
tmpfs /dev/shm tmpfs rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw 0 0
bigfoot:/ecad /ecad nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/pd1 /pd1 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/pd3 /pd3 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/pd5 /pd5 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/pd6 /pd6 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/pd8 /pd8 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/dv3 /dv3 nfs rw,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
asteroid:/dv4 /dv4 nfs rw,tcp,nfsvers=3,rsize=65536,wsize=65536 0 0
asteroid:/dv5 /dv5 nfs rw,tcp,nfsvers=3,rsize=65536,wsize=65536 0 0
bigfoot:/dv6 /dv6 nfs rw,tcp,nfsvers=3,rsize=65536,wsize=65536 0 0
bigfoot:/pd7 /pd7 nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0
bigfoot:/t6_dump /t6_dump nfs ro,sync,tcp,nfsvers=3,rsize=262144,wsize=262144 0 0

Thanks

michaelk · 08-31-2015, 10:51 AM

Yes, you did not include swap and your / does not belong to a LVM. Those values are the defaults so it should not matter.

Does not go in fstab.
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw 0 0

sagar666 · 08-31-2015, 12:58 PM

Hi Michael,

So you are telling i have not added swap and root partition in fstab file? and none sunrpc isnot need in fstab Right?

michaelk · 08-31-2015, 01:08 PM

Yes, what you posted for your root partition is not correct.

Code:

LABEL=/  /    ext3    rw      0 0

sagar666 · 09-08-2015, 05:34 AM

Hi Michaelk,

One my server shows blkid like below

/dev/sr0: LABEL="RHEL/5.7 x86_64 DVD" TYPE="iso9660"
/dev/sda3: LABEL="/share1" UUID="c991154f-fa69-4340-914f-3e114950a136" TYPE="ext3"
/dev/sda2: LABEL="SWAP-sda2" TYPE="swap"
/dev/sda1: LABEL="/1" UUID="542a5bd7-3057-43c4-96a7-668f2d34c6c2" TYPE="ext3"

For above blkid i need to write /etc/fstab for root like below?

LABEL=/1 / ext3 rw 0 0

why it is showing like /1?

Also boot partition not showing why in blkid output?

michaelk · 09-08-2015, 08:51 AM

Tell us what you did?

It appears that you reinstalled along side the original. You can't have multiple partitions with the same label so the installer adds a 1. And during the install process you did not select a boot partition.

sagar666 · 09-08-2015, 09:11 AM

Hi Michaelk,

As i said earlier i overwrite the fstab entry in almost 50 server. Today i tried correct fstab entry as you suggested earlier but when do blkid its showing like below and i wondered why boot file system not showing when i do blkid

/dev/sr0: LABEL="RHEL/5.7 x86_64 DVD" TYPE="iso9660"
/dev/sda3: LABEL="/share1" UUID="c991154f-fa69-4340-914f-3e114950a136" TYPE="ext3"
/dev/sda2: LABEL="SWAP-sda2" TYPE="swap"
/dev/sda1: LABEL="/1" UUID="542a5bd7-3057-43c4-96a7-668f2d34c6c2" TYPE="ext3"

I have not reinstalled any thing and same behavior in few more machines.

michaelk · 09-08-2015, 09:20 AM

Sorry you did mention 50 servers. About all I can say is the installations are not identical and these servers do not have a separate boot partition.

sagar666 · 09-08-2015, 09:42 AM

So without boot partition system will boot? I guess root and boot partition are mandatory Right?