RAID 1 backups.. better to get different drives?

[Tom B]

I'm planning on using two 1tb SSDs for backup purposes in RAID 1. I want to use SSDs because I want a silent solution as backups will be taken automatically overnight while I'm trying to sleep.

My question is, am I better using different brands? The OCD in me says I should get two identical drives, but the pragmatist in me asks: "Are two identical drives with identical data being written to them more likely to fail at the same time?" as the purpose here is backup, I wonder whether it would be better to get two different brands/models as they'd be less likely to fail at the same time?

Any performance overhead caused by mismatched drives is irrelevant here as they're just for backup and reliability is the important factor here.

 

[Tom B]

Isn't the entire point of RAID 1 to have duplicated data?

edit: I'll be using git or rsnapshot to manage versioning of the data so deletion isn't really the problem, I just want the data written to both drives in case one fails.

 

[Tom B]

Yes, but duplicated data isn't the same thing as a backup

Corruption may get duplicated between drives, viruses may get duplicated between drives, and deleted/overwritten files get duplicated between drives.

Perhaps I should have explained what I'm doing. I want to back up my desktop to another computer in my flat and I want to protect the backup server from drive failure. My /home directory is tracked via git and i'm going to push all changes to the file server nightly in a cronjob. Perhaps you're right, I'll manually push changes to both drives. (I may change this to use rsnapshot as it's probably a bit more suitable than git)