Mounting to Hard Drives to one Mount Point

goldennuggets · 03-29-2020, 07:05 AM

I was wondering if the following is possible?

Hard drive one mounted to /home/
This hard drive starts to fill up.

Hard drive two also (somehow) mounted to /home/

Is this a possibility? If so, how?
If it's not, why isn't it a possibility? I'm not asking to be snarky, I'd truly like to know and understand.

syg00 · 03-29-2020, 07:18 AM

No.
When you mount the second (larger) drive to /home, the previous mount (and all the files there-in) is hidden under the later mount. A better option is to mount the second disk at a subdirectory - say /home/videos or somesuch. You still have the same issue, but probably more manageable - just move the old videos out of the way first, and later reload them back.

berndbausch · 03-29-2020, 07:21 AM

You can mount as many disks as you like to /home, but the most recent mount will hide all the others rather than merging the storage space. Why? It has been the semantics of mount since the inception of UNIX.

If you want to extend a filesystem over several disks, use RAID or a volume manager (LVM is built-in). A union mount may also help.

goldennuggets · 03-29-2020, 07:21 AM

Quote:

Originally Posted by syg00

No.
When you mount the second (larger) drive to /home, the previous mount (and all the files there-in) is hidden under the later mount. A better option is to mount the second disk at a subdirectory - say /home/videos or somesuch. You still have the same issue, but probably more manageable - just move the old videos out of the way first, and later reload them back.

Thanks! Much appreciated. That makes perfect sense and I thank you too, for a reasonable alternative solution!

goldennuggets · 03-29-2020, 07:25 AM

Never knew about union mounts before. Interesting read. Thank you.