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.
This is a good guide: https://wiki.tnonline.net/w/Btrfs/Replacing_a_disk
Usually you want to replace drives before they fail (SMART monitoring will give you ample warning in most cases). The it is better to have an additional free SATA port to turn the failing raid temporarily into a three-way raid and use the btrfs built-in function to replace the disk in situ.
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.
Could I purchase two different brand drives and use them with btrfs?
I don’t quite remember the source for this, but I believe I read some time ago that it’s actually a good thing to have separate drives. The reasoning is, if you buy two identical drives (at the same time), the likelyhood of both drives failing around the same time is severely higher.
This is then amplified by the fact that rebuilding a RAID puts a lot of strain on the non-dead drive, so if ie. drive 1 dies and drive 2 is about to die, the strain you put on drive 2 in order to rebuild your RAID onto drive 3 might kill drive 2 before you even finish rebuilding your RAID.
Again, this is just from my memory, it might be worth doing some more research on.
if you buy two identical drives (at the same time), the likelyhood of both drives failing around the same time is severely higher.
I need sources, this sounds extremely unlikely. That’s basically 2 "independent” probabilities.
The reasoning is that drives are produced and shipped in batches and if you order multiple at onces there is a higher chance you’ll get drives from the same batch. If that batch had some fault during production or it was damaged during shipping, all your drives might be affected.
I don’t have a source, but it’s something multiple expirenced people have mentioned to me.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
| Fewer Letters | More Letters |
|---|---|
| NAS | Network-Attached Storage |
| RAID | Redundant Array of Independent Disks for mass storage |
| SATA | Serial AT Attachment interface for mass storage |
| SSD | Solid State Drive mass storage |
| ZFS | Solaris/Linux filesystem focusing on data integrity |
5 acronyms in this thread; the most compressed thread commented on today has 9 acronyms.
[Thread #873 for this sub, first seen 16th Jul 2024, 15:35] [FAQ] [Full list] [Contact] [Source code]
Just if somebody else needs this for ZFS: https://blog.juhefa.de/posts/zfs-replace-disk/
