Upgrading Raid 5 to larger disks
I have a 6x 4TB Raid 5 array in 2x OWC Thunderbay 4's. I've used 14TB of the 20TB available. Figure I shouldn't go over 15TB (75%), correct? Drives have about 17k hrs, HGST enterprise class.
So I'm thinking to 'upgrade' the array to 6TB or 8TB drives sometime in the near future. Prefer to keep Raid 5 for its speed.
I don't have enough drive bays to just add a second 6 drive array and transfer. What's the best practice?
Clone each drive one at a time with CCC? Or just replace drives one at a time and let it 'rebuild'?? I guess I could just use my individual backup drives (non-raid) to move the data.
Second question - I've just read that I should 'Validate' my array in Softraid regularly. I didn't realize and have run it for 6 years and never validated. Kind of scared to do so now if it means it'll need to rewrite tons of data. Any advice?
27" 5k iMac late-2014
2x OWC Thunderbay 4
6x 4TB Raid 5
I think 85% is OK on a volume. (I don't know what the optimal limit is on APFS, I guess users will find out over time!)
Validate is safe. All it does is check adn update any parity blocks. There will probably be no updates until the last 20% or so of the volume. Validate does not touch your data.
Disk Warrior is the best way to protect your volume against volume directory damage, if you want to run a maintenance app.
To your question:
You can replace one disk at a time. Use "remove disk", then initialize and "Add disk". When all 4 are replaced, you can "resize volume" to expand the volume size, and use the additional space available.