So here I was, thinking I’d switch my 2+2+1TB RAID1 to a 2+2+2TB RAID5, instead of a 2+2+4TB RAID1, and still end up with the same amount of usable space. After reading threads like these, I’m hesitating. For me, most of the data would be either backed up remotely or easily replacable, so any “real” problems I’d run into could, worst case, be solved by wiping the array and starting over. Still a hassle, of course.
I’m also wondering what scrub times are like for a <10TB array consisting of at most 4 drives. I keep hearing that it’s much worse than RAID1, but I’d be open to input about smaller arrays like mine (I don’t consider 3 or 4 2TB drives “a lot” - I’ve seen folks with way, way more) that are basically a home NAS / media storage / Nextcloud instance.
If switching to RAID5 is not discouraged as much as it used to be, I’m also wondering what the best order of things would be. Clear up some space, remove the 1TB (and rebalance, I suppose), add the 2TB and convert to RAID5 in one go? Or are there better, quicker ways?
Edit: let’s add some more info, in case it’s relevant. My system is a HP Gen8 microserver (the Celeron-powered one) with 6GB of RAM. Currently, a scrub of the RAID1 takes about 3.5 hours. Data is a mix of backup files, websites, and movie stuff, so both smaller and larger files. The system is mostly used by just me. Anything else in terms of usage that might be relevant?
Edit 2: Possibly related - it is of course possible to use RAID1 for metadata rather than another level, and in coming kernel versions it seems like multi-copy RAID1 will be a thing, too, as well as increased performance. Maybe I should start out with going for that newer kernel, first…