Me and my friend were discussing this the other day about how he said RAID is no longer needed. He said it was due to how big SSDs have gotten and that apparently you can replace sectors within them if a problem occurs which is why having an array is not needed.
I replied with the fact that arrays allow for redundancy that create a faster uptime if there are issues and drive needs to be replaced. And depending on what you are doing, that is more valuable than just doing the new thing. Especially because RAID allows redundancy that can replicate lost data if needed depending on the configuration.
What do you all think?
Suppose you’re hit by a ransomware attack and all the data on your NAS gets encrypted. Your RAID “backup” is just as inaccessible as everything else. So it’s not a backup. A true backup would let you recover from the ransomware attack once you have identified and removed the malware that allowed the attack.
I really, really liked @[email protected]’s answer, because even as I was reading it, I was thinking of things that they could have said—but didn’t—which would have been easily rebutted. Those things fell into two basic categories: malware, and environmental effects.
As I understand it, malware is an issue with any online backup system, whether that’s a RAID or just a second external hard drive. So I don’t really think it works as an answer to why RAIDs specifically don’t qualify as backup.
A well thought out and implemented backup system, along with a good security setup is how you deal with malware. If backups won’t protect you from malware then you’re doing backups wrong. A proper backup implementation keeps a series of full backups plus incremental backups based on those full ones. So say your data doesn’t change very often, then you might do a full backup once a month and incremental ones twice a week. You keep 6 months of the combinations of full & incrementals, you don’t just overwrite the backups with new ones.
If you’re doing backups like that and you suffer a malware attack then you have the ability to recover data as far as 6 months ago. The chances you don’t discover malware encrypting your data for 6+ months is tiny. If you’re really paranoid then you also test recovering files from random backups on a regular basis.
My employer has detected and blocked multiple malware attacks using a combination of the above practices plus device management software that can detect unusual NAS activity and block suspect devices on our networks. Each time our security team was able to identify the encrypted files and restore over 99% from backups.