USB Drives are bad... but?

[gdaniel]

Hi, Im planning to make my nas and upgrade from an old Asustor one.

The system would be based on Thinkcentre M710q i5 7thgen, 8gb ram, main purpose Nextcloud + Plex (direct play) + torrent.

Main plan, internal SATA for boot, m2 ssd for application/plugins and 2 usb drives mounted for nextcloud (probably mirror) and 3rd for plex.

For nextcloud my plan was to use 2 usb drives as mirrored and an extra for plex + torrent. For nextcloud I would also rsync the data to my Asustor nas for offsite backup.

But after this I just read USB drives are not recommended and i have no ecc ram too.

If I use mirror on the 2 USB drives, then if one of them disconnects (bad connection) would it be reconnect and basicly everything continues as the other drive is still there? Or I could loose all my data becase something gets corrupted? (i have backup on my asustor but staying on the truenas instance)

Also ECC ram, my pc running currently for year without any problem constantly, basicly never had any issue with ram on truenas i would only get like a system restart if one of the rams would start going bad no? Already existing data should be safe right?

Im a simle home user, I don't need nasa and google security but I want to know before I spend this little money that one little usb disconnect would not corrupt all my truenas data if I use mirroring ( or should I use daily snapshot instead? I can live with one day data loss as images would be still on my phone with auto sync).


Thanks in advance!

 

[sretalla]

Using USB permanently as a connection method for pool/data disks is going to end in controller failure at some point... just a question of when and if it fails in a way which could risk your data or not (clearly mirrors help, but the risk is there nonetheless).

Designing it to run like this from the outset is in my opinion foolish. If you value your data, don't do it like that.

ECC RAM isn't a "requirement" and using non-ECC RAM doesn't inherently risk trashing all your data at any moment, but you need to ask the question in the context of "why am I using ZFS at all?"... if your answer is because you care about the data and data integrity is an important factor (maybe not as critical in some cases where an occasional bit-flip won't kill the entire file/library/database or whatever), then ECC would be something you would want.

Using USB drives is planning for early and frequent failure of your pool disks (at least the controllers via which they attach). Failures risk something... maybe just the controller needing replacement, but maybe messing up the data inflight at some point.

The choice is yours, but take it from somebody who has experience with using USB enclosures and ZFS (in my early days with FreeNAS)... it's not worth the trouble.

Maybe you would be happier with OMV/UNRAID/Xpenology if that's the only hardware you're prepared to go with.