I’m looking at different options for getting a NAS/RAID array system that is tolerant to not just hard drive failures but also to hardware/firmware and board failures. I’ve utilized a RAID array in the past that was built into the motherboard, which resulted in the motherboard failing and me having to ebay another one to get the RAID array back up and running. Then I bought a NAS 2 bay drive that was only compatible with drives up to 1.5TB. I’ve also used external drives for backup since I’ve been burned by hardware/firmware/software issues related to RAID arrays. Are there are any PCI RAID cards, NAS boxes or software RAID or other options where the hard drives would still be readable by other RAID cards if the boards failed? Maybe a software RAID solution? Any thoughts would be appreciated.

  • mea_rah@lemmy.worldEnglish
    1·
    1 year ago

    The author is upset that btrfs RAID arrays don’t function as he anticipated. However, btrfs isn’t ZFS or mdadm; it’s its own system and should be understood as such.

    I’d say it’s quite reasonable critique, because RAID1 is kind of industry standard. I can’t think of any other RAID (HW or SW) that would do RAID1 in this way. If btrfs decided to call their implementation raid1 while it really isn’t raid1 in some major way, it was very bad idea. I don’t agree it’s documentation issue, it’s really bad name choice. ZFS has raidz that does something similar to btrfs raid1 and the name does not lead to confusion. RAID1 system should never lead to decreased reliability with increasing number of drives.

    The author points out that btrfs won’t auto-mount an array if a drive fails, while ZFS will. This is actually a protective measure. By not auto-mounting, it minimizes the risk of further drive failures, prioritizing data preservation.

    RAID is uptime preserving mechanism. If anyone uses RAID for data preservation purposes, they are setting themselves for a nasty surprise. RAID system that does not mount in reduced redundancy situation is very bad design. It effectively sacrifices usability of RAID to serve other purpose that RAID system does not really need nor should be used for.

    He attempts ZFS recovery methods on btrfs and is surprised when they don’t work.

    I felt that way as well, but I think they raised one important point - there was no indication that the array was still in reduced redundancy state after their “attempt at recovery”. ZFS is very clear about the state of array at every step. Same for other RAID systems including some HW based ones. Every single one I’ve used were very clear about the fact that array isn’t fully redundant.

    In summary, the article’s author seems primarily upset that btrfs isn’t a ZFS clone.

    FWIW I didn’t have that impression. I have experience with multiple RAID controllers and multiple SW RAID systems and his points would be valid with any of those.

    Anyways thank you for your reply. It’s not the answer I was hoping for and I don’t agree with your views on some of these issues. But it gives me pretty good idea of the current state of the filesystem.