Whats a better choice?

[jason4207]

A friend of mine is saying unraid is a terrible way to go cause when you loose a drive there's a huge chance of me loosing all my data, is there right? He mentioned to use ZFS instead with raidz and possibly do a raidz2 set up, what do you guys think about this?

No experience w/ ZFS/raidz2, but I've never heard anything about a "huge chance of losing all data" on unRAID. That's the whole idea behind unRAID; that the data is stored just like it would be if it was on a single disk except that there is added parity protection using an additional disk. If you lose 1 or even 2 or more drives all the rest of the drives still have all their data, and parity can be rebuilt using that data. The data isn't stripped so it doesn't go away w/ array failure like in RAID5/6.

You can take 2 or more drives out of an unRAID array, and put them in the closet. You can then rebuild parity based on the data still present (this will get rid of the parity info on the 2+ removed drives). 1yr down the road you can take those 2+ drives out of the closet and add them back to the array. You can then rebuild parity again to restore parity protection on all drives. All the data on those drives you removed will still be there.

If your friend has a source for his info then I'd like to read it.

This guide looks very similar to how mdraid is setup. But they do mention the "array" was only able to get 20MB/s throughput but this could be caused by the checksumming.

unRAID gets ~20MB/s writes w/o a cache disk (might be faster now, but that's what it was a couple years ago), but w/ a cache disk it gets write speeds equal to a single drive; ~100MB/s.