Forum Discussion

Luminary

Mar 26, 2019

Choice of file system for external backup hard disk

Hi, I have used my ReayNAS 314 for a few years and run the latest OS on it. Regularly I make backup on an external HD of the important part of what is stored on the NAS. I have two external bac...

StephenB

Guru - Experienced User

Mar 26, 2019

janpeter1 wrote:

I consider now to make the full backup from scratch on the EXT3 disk and I consider to swith to BTRFS here too. I am just curious what you would recommend. Is BTRFS "stable" enough to use for both my backup? Other reasons to actually continue with EXT3?

I think it's stable enough (and if it weren't then you shouldn't use it for either backup). The main thing is that you want to be able to access the files using something other than the NAS. If you have a linux PC, then you should install btrfs, and make sure you can read both back up drives. If you don't have a linux PC, then you should be using NTFS.

janpeter1 wrote:

Is it good too divde the backup in parts so that the NAS can "rest" for some time or it is just to run it all.

I think it's fine to just run it all. Also, if you are making incremental backups, then it's a good idea to occasionally make a full one (just to make sure there are no underlying disk errors).

Hopchen

Prodigy

Mar 26, 2019

I use BTRFS on my USB devices. I like that because I can snapshot by data on the USBs. It is fantastic for backup versioning, for example.

StephenB
Guru - Experienced User
Mar 26, 2019
Hopchen wrote:

I use BTRFS on my USB devices. I like that because I can snapshot by data on the USBs. It is fantastic for backup versioning, for example.

I assume you are doing that yourself (from ssh), since the built-in backup jobs don't have that facility. Is that correct?
- Hopchen
  Prodigy
  Mar 26, 2019
  Yup that is correct. I wish that was a feature in the NAS admin panel. I have a cronjob that does this for me :)
  - janpeter1
    Luminary
    Mar 27, 2019
    Thanks for the comments but I like to sharpen my questions.
    
    The reason for me to make both external HD to be BTRFS is that I "imagine" that since the NAS is on BTRFS then if backup is also on BTRFS then I get a slightly higher degree of safety of data integrity, compared to having the external HD as EXT3 (or EXT4)
    
    The drawback is you put all eggs in the same basket, so to speak. But I guess by now BTRFS on ReadyNAS has matured and I have had no problems these years I have used it. But I have not tested it much though.
    
    So is here a gain in data integrity by having the external HD in BTRFS, however small? Or there is too many other sources of corruption anyway so it does not matter. After all I have an ordinary NAS and not the one with special RAM-memory to protext agains data corruption there.
    
    What do you think?