NOTE: You will need to be logged in as root via a ssh shell to your server.
Running fdisk -l will output all physical hard drives connected to your server.
You're looking for names such as /dev/sda and /dev/sdb
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
Disk /dev/sdb: 500.1 GB, 500107862016 bytes
You can verify which drive is already mounted by typing the following command.
You should see one or more /dev/sdax partitions mounted currently.
/dev/sda3 on / type ext3 (rw,errors=remount-ro)
Using these two commands make note of your old drive (which wont show up under mount yet)
and make note of the largest linux partition that is partitioned as type 83 (ext3 filesystem.)
In the following example fdisk -l will output the partitions from your old drive (sdb)
Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 60000255 29999104 83 Linux
/dev/sdb2 60002304 71999487 5998592 82 Linux swap / Solaris
/dev/sdb3 72001536 976773119 452385792 83 Linux
You don't need the boot partition (noted by the boot flag) or your swap partition (virtual ram).
/dev/sdb3 is your linux filesystem that you want to mount to recover your files.
To mount your drive issue the following commands:
NOTE: (make sure to use the corresponding drive name in the following commands /dev/sdax or /dev/sdbx where x is the partition of your linux filesystem from the old drive)
First make a directory to mount the drive into.
Then mount the old drive into that directory.
mount /dev/sdb3 /mnt/olddrive
Provided their were no errors output your old drive is now mounted and you can browse to that directory and begin copying files as necessary.
To un-mount the old drive issue the following commands.
Note: If you reboot your server, the old drive will not be mounted automatically and you will have to mount it again using this process. Posted in