btrfs drive replacement

Dust0741@lemmy.world to Selfhosted@lemmy.world – 29 points –

Referencing: https://lemmy.world/post/17588348

I want to make a NAS with a 500GB boot drive and 2x16TB HDDs. Based on my previous post, btrfs is a good option. It also looks easy to get started. My plan for the NAS would be to purchase several 16TB drives, and only use 2 of them.

My first question is about different drives. Could I purchase two different brand drives and use them with btrfs? (I assume yes)

2nd question: how does the replacement process go? Like if drive A died, so I remove it, and put a brand new replacement in. What do I have to do with btrfs to get the raid 1 back going? Any links or guides would be amazing.

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My first question is about different drives. Could I purchase two different brand drives and use them with btrfs? (I assume yes)

You can.

2nd question: how does the replacement process go? Like if drive A died, so I remove it, and put a brand new replacement in. What do I have to do with btrfs to get the raid 1 back going? Any links or guides would be amazing.

Depends on what NAS/Software you have. If your NAS supports hot-swaps you can just pull out the defective drive and plug in another. Otherwise you'll have to shut it down, swap the drive and turn it back on.

If you have already have the spare drive ready and you have slots availible, you can run a "hot spare". This way you can even start the raid rebuild if you're not physically near your NAS (like when a drive fails while you're on holiday or sm).

Hm okay. I was thinking of using Debian and likely a 4 bay case.

So the process for a dead HDD: Power off. Pull out dead drive and replace. Power on. Now what? Does Debian/a specific motherboard support auto rebuilding the raid 1? Or what are the commands to rebuild?

Btrfs has it's own build-in raid. From what I understand you should mount the filesystem with -o degraded and then use btrfs replace to switch to the new drive. I've never had to do that myself yet though.

I'm using Synology/DMS and there you have a pretty neat GUI that lists newly detected drives and let's you assign them to your storage pool and rebuild the raid. I'd expect it to be quite similar on software like TrueNAS Rockstor.