It make no sense today for me anymore…I found more downside than real use of my RAID5 array.
My setup: 5 disks of 22TB in Raid 5
- Data Organising is estimated to 20 days!
- Rebuild time of RAID5 is unknown never had to do (yet) :-)
- Disks never sleep in BTFRS, power cost is here 0.30 per kWh
- Constant noise of 5 disk clicking instead of only one or two when using
- Do I need 80TB of continuous stiorage? Not really with 2700 movies= 12TB, 8000 TVShow episode= 14TB, most is still in h264 few in h265 and really really few in AV1 (fantastic by the way)
- I dont care about Media, and rebuild everything on a 10GB Fiber most of it automatically. Most of my private stuff is on 3-2-1 encrypted anyway
- High availability is not a topic, I’m alone using this box. And even, my Homelab is best effort not 24/7
I have another NAS full SSD, with 8 SSD but I hate the nature of RAID in SSD: they die unexpected most of the time. I prefer to lose 4TB then put 30TB at risks if 2 or more SSD decide to stop working
So maybe duplicating on another disk in a mirror (rsync) is maybe better for me
RAID5 has been dead in commercial contexts for around 10 years. Reason is the resilver time is just too long. Now mostly you either use striped mirrors or do redundancy on the software level.
How is rebuilding an xx TB mirrored disk faster than rebuilding an xx TB disk that’s part of a RAID? Since most modern NASes use software RAID, it’s only a matter of tweaking a few parameters to speed up the rebuild process.
Rebuilding parity requires processing power. Copying a mirror does not.
There’s also the fact that the rebuild stresses the drives, increasing the chance of a cascade failure, where the resulting rebuild after a drive failure, reveals other drive failures.
It all results in management overhead, which having to “just tweak some parameters” makes worse, not better.
In comparison to simple mirroring and backing up offsite, RAID is a headache.
The redundancy it provides is better achieved in other ways, and the storage pooling it provides is better achieved in other ways.
That shouldn’t be an issue with any NAS bought in the past decade.
You can tweak the parameters so the rebuild is being done slower. Also, mirroring a disk stresses the (remaining) disk as well. (But to be fair, if that one fails, you’ll still be able to access the data from the other mirror-pair(s).)
I’m not seeing that. Tweaking parameters is not necessary unless you want to change the default behaviour. Default behaviour is fine in most cases.
Speak for yourself. I rather enjoy the added storage capacity.