Moving /var, /home to separate partition

Question

I am attempting to move some folders (such as /var and /home) to a separate partition after reading this guide:

3.2.1 Choose an intelligent partition scheme

I was able to move one folder successfully following thisguide.

However, it doesn't seem to work for multiple folders, and all my folders are dumped into the partition without proper folders.

I would like to mount /var, /home, and /tmp onto the separate partition; can someone guide me on this?

Answer 1

1. First you need some unallocated space to create the partitions for each mountpoint (/var, /home, /tmp). Use Gparted for this.

2. Then you need to create the filesystems for those partitions (can be done with Gparted too) or use:

mkfs.ext4 /dev/sdaX

for example to create a new ext4 filesystem on the /dev/sdaX device (replace /dev/sdaX with your own device)

3. Mount the new filesystem under /mnt

mkdir /mnt/var        
mount /dev/sdaX /mnt/var

4. Go to single-user mode so that there is no rw activity on the directory during the process

init 1

5. Enter your root password.

6. Backup data in var only (not the /var directory itself)

cd /var
cp -ax * /mnt/var

7. Rename the /var directory after your data has been transferred successfully.

cd /
mv var var.old

8. Make the new var directory

mkdir var

9. Unmount the new partition.

umount /dev/sdaX

10. Remount it as /var

mount /dev/sdaX /var

11. Edit /etc/fstab file to include the new partition, with /var being the mount point, so that it will be automatically mounted at boot.

/dev/sdaX       /var     ext4    defaults    0 0

12. Repeat steps 1-11 for /home and /tmp.

13. Finally return to multitasking mode.

init 5

Answer 2

If you want to use them all on the same partition you can either use LVM or three simple bind mounts.

To create a bind based solution you

1. create a partition with a filesystem
2. go to rescue mode (single user still needs some of the folders)
3. mount it as /mnt/data

4. Move all folders you want to move. Using cp and mv dir dir.old might be safer, but since I did this after install it did not matter to me.

   mv /home /mnt/data/
   mv /var  /mnt/data/
   

5. create appropriate bind mount entries in fstab, for example I have

   UUID=01234567-89abc-def0-1234-567890abcde /mnt/data         ext4          noatime,nodiratime,relatime                           0       0
   
   # Binds
   /mnt/data/opt                             /opt              none          bind                                                  0       0
   /mnt/data/home                            /home             none          bind                                                  0       0
   /mnt/data/usr                             /usr              none          bind                                                  0       0
   

6. reboot

Answer 3

I'd personally either go with @Fabian's bind-mount solution or use symlinks:

1. create /etc/fstab entry for the new partition (use blkid to get the right UUID for your new partition and don't forget to mkdir /mnt/data):

   UUID=01234567-89abc-def0-1234-567890abcde  /mnt/data  ext4  defaults  0 0
   

2. Use mount -a or something similar to mount the new partition

3. move the original folders to your new partition:

   mv /var /mnt/data/
   mv /home /mnt/data/
   # ... (you get the point)
   

4. Create symlinks

   ln -s /mnt/data/var /var
   ln -s /mnt/data/home /home
   # ...
   

Although the bind-mount method is probably the best practice solution I kind of prefer this one because you don't end up with unnecessarily long df and mount partition lists.

Answer 4

In addition to the procedure given cioby23, I also had to do:

  restorecon -R /var

in order for sshd to start.

Answer 5

mounting your /var directory on a different partition. Let’s get started by attaching a new LVM, partitioning, and creating a desired file system.

Create a LVM Using New Disk: /dev/sdb

# pvcreate /dev/sdb
# vgcreate  vg_var /dev/sdb
# vgdisplay
# df -Th
# lvcreate -n lv_var -l +<PE Free Size>
# mkfs.xfs /dev/mapper/vg_var-lv_var
# lsblk

Create a new mount point and mount your new partition:

 # mkdir /mnt/var
 # mount /dev/mapper/vg_var-lv_var  /mnt/var/

Start Sync /var to the new temporary mounted partition

# rsync -aqxP /var/* /mnt/var  

Unmount the temporary Partition after a successful sync

# umount  /dev/mapper/vg_var-lv_var /mnt/var/
# lsblk

Edit your /etc/fstab to include a new partition and choose a relevant file system:

/dev/mapper/vg_var-lv_var  /var                 xfs     defaults        0 0

Reboot your system and you are done. Confirm that everything is working correctly and optionally remove the old var directory by booting to some Live Linux system etc.

Answer 6

Is there a way to skip the unmounting of var ( running processes)? Under new Debian versions even root in init 1 mode is denied access to renaming var into var.old when process is running (in log/journaling for example).

You could create a varnew partition following all of Stephen's steps, then

following the edits mentioned in Stephen Rauch's solution in etc/fstab:

add stephen's line (before!) the previous line where var was mentioned

/dev/sdaX /var ext4 defaults 0 0

then change the old name in the old line in fstab from var to varnew, for example:

yourPhysicalVolumeGroup-VG-var /var

would becomes

yourPhysicalVolumeGroup-VG-var /varnew

and this would be implemented upon your system restart without affecting on-going processes in /var at the time of the editing.

then in normal or init 5 mode, sudo rm -R var would be possible.