Comment by zelcon
5 days ago
You need to buy the same exact drive with the same capacity and speed. Your raidz vdev be as small and as slow as your smallest and slowest drive.
btrfs and the new bcachefs can do RAID with mixed drives, but I can’t trust either of them with my data yet.
It doesn't have to be the same exact drive. Mixing drives from different manufacturers (with the same capacity) is often used to prevent correlated failure. ZFS is not using the whole disk, so different disks can be mixed, because the disk often have varying capacity.
You can run raid-z across partitions to utilize the full drive just like synology does with their “hybrid raid” - you just shouldn’t.
> You need to buy the same exact drive
AFAIK you can add larger and faster drives, you will just not get any benefits from it.
You can get read speed benefits with faster drives, but your writes will be limited by your slowest.
Just have backups. I used btrfs and zfs for different purposes. Never had any lost data or downtime with btrfs since 2016. I only use raid 0 and raid 1 and compression. Btrfs does not havr a hungry ram requirement.
Neither does zfs, that’s a widely repeated red herring from people trying to do dedup in the very early days, and people who misunderstood how it used ram to do caching.
Tbh the idea of keeping backups defeats the purpose of using RAIDZ (especially RAIDZ3). I don’t want to buy an LTO drive, so if I backup, it’s either buying more HDDs or S3 Glacier ($$$). I like RAIDZ so I don’t have to buy so many drives. I guess it protects you if your house burns down, but how many people do offsite backups for their personal files? And dormant, unpowered HDDs die a lot faster than live, powered HDDs.
Yes, seriously handling your data is expensive. I am talking about buying new hardrives.
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