Hi,

Recently I have edited the file /etc/fstab and did something stupid.
At first it looked like this :

/dev/mapper/server--vg-root / ext4 errors=remount-ro 0 1
/dev/mapper/server--vg-home /home ext4 defaults 0 2
/dev/mapper/server--vg-tmp /tmp ext4 defaults 0 2
/dev/mapper/server--vg-var /var ext4 defaults 0 2

Then in /etc/fstab I did this change (3rd line, var -> home)

/dev/mapper/server--vg-root / ext4 errors=remount-ro 0 1
/dev/mapper/server--vg-home /home ext4 defaults 0 2
/dev/mapper/server--vg-tmp /home ext4 defaults 0 2
/dev/mapper/server--vg-var /var ext4 defaults 0 2

and did a reboot. The system did not like it so I switched back to original setup. After a reboot the system was unable to find the /home directory on my server.

Is there a possibility to recover those files? Nothing has be written since the reboot.

Thanks a lot for your help!

As root, show us

and probably additionally:

Hi,

So below are the results of the commands. I also realized I might be unclear, sorry : I see the /home directory, it is just empty and the home directories of users are not there anymore. The /home is empty.
Thanks for your help.

$ sudo ls -ld /home :

drwxr-xr-x 7 root root 4096 Dec 6 15:48 /home


$ ls -l /home :

total 0
srwxr-xr-x 1 root root 0 Dec 6 15:44 sddm-auth31d0020d-968a-4789-b759-9130a41c229d


$ df -h /home

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/server--vg-home 21T 28K 20T 1% /home


$ mount :


sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=528125368k,nr_inodes=132031342,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=105629276k,mode=755)
/dev/mapper/server--vg-root on / type ext4 (rw,relatime,errors=remount-ro,stripe=256)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
mqueue on /dev/mqueue type mqueue (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=43,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=166317)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
/dev/nvme1n1p1 on /scratch1 type ext4 (rw,relatime)
/dev/nvme0n1p1 on /scratch0 type ext4 (rw,relatime)
/dev/sda2 on /boot type ext2 (rw,relatime,stripe=1024)
/dev/mapper/server--vg-var on /var type ext4 (rw,relatime,stripe=256)
/dev/sda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro)
/dev/mapper/server--vg-tmp on /tmp type ext4 (rw,relatime,stripe=256)
tmpfs on /run/user/114 type tmpfs (rw,nosuid,nodev,relatime,size=105629272k,mode=700,uid=114,gid=120)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,relatime)
tmpfs on /run/user/1002 type tmpfs (rw,nosuid,nodev,relatime,size=105629272k,mode=700,uid=1002,gid=1002)
/dev/mapper/server--vg-home on /home type ext4 (rw,relatime,stripe=256)

it looks like the partition is ok, available and mounted. But the content is lost. I guess you made something else too.

I think it is all I did. But as I explained I changed

/dev/mapper/server--vg-tmp /tmp ext4 defaults 0 2

to

/dev/mapper/server--vg-tmp /home ext4 defaults 0 2

then I did a reboot and then came back to the original step.

So what happened during this step? Since /home was already existing, I guess this is when the lost of data happened.
Another point : after the first reboot, I was able to login by ssh keys (so the homes where still there I guess). After the second reboot, I add to enter my password and I got the message '/home/monlogin' is not accessible.

Nothing bad should have happened because of that alone. See this SE question and this LQ thread.

The only plausible explanation I have is that what you actually did was the direct opposite of what you described.

I.e. instead of
you did home -> tmp
In that case, /dev/mapper/server--vg-home which was thought of as /tmp by the system could indeed get cleaned on reboot.

Thanks for your reply.

No, I am sure I did not swap the two entries.
But I actually remember something else (sorry for remembering only now, I did not do this last step myself :/ ). At the end, because of a wrong copy paste the file /etc/fstab became (3rd line has changed)

/dev/mapper/server--vg-root / ext4 errors=remount-ro 0 1
/dev/mapper/server--vg-home /home ext4 defaults 0 2
/dev/mapper/server--vg-tmp /tmp2 ext4 defaults 0 2
/dev/mapper/server--vg-var /var ext4 defaults 0 2

but tmp2 did not exist ...
So the server was not able to reboot (it was trying to find the partition) and a manual reboot was necessary. It was after that step that the homes disappeared.

the facts: /home (and /tmp2) will not be deleted magically by any tool, any software.
/tmp can be deleted automatically during boot, that may depend on your OS/configuration.
So either you executed a command yourself (to clean that filesystem) or was handled as /tmp.
Anyway, you may try to use a recovery tool to look for your lost files (for example: https://likegeeks.com/recover-deleted-files-on-linux/)