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?
I do recall google apparently stopped using raid in some data centres, but it was because they had whole-machine redundancy.
RAID is probably redundant for some of the uses it used to have, like optimising read performance by using many drives (SSD is fast) and honestly I suspect that SSDs are probably more reliable as they don’t have a bunch of platters and bearings and screaming rotational speeds.
So if you needed it for a base level of reliability, an SSD on its own may have exceeded that.
I suspect there are still uses for drive redundancy in some high availability setups… although your friend might be right. If the likelihood of drive failure is lower than other parts in the machine and you need high redundancy for availability it might make more sense to replicate the whole machine rather than the drives.
It’s possible redundancy specifically for the drives was an artifact of unreliable drives back in the day 🤔 they might have a point! I think it’s likely still useful at times though.
I’d rather hotswap a drive than set up a new server, even if it’s a less likely scenario.