Stupid spell check I meant to write, one parity disk (not enough for my data as I'd like at least two disks or even more as the spindle count increased). The lack of bitrot protection means that it does not provide checksumming for data to ensure it's accuracy like ZFS, btrfs, refs, or other snapshot RAID solutions like SnapRAID or FlexRAID. If you'd like to read more, take a look at this article.Still only one part disk and no built-in bitrot protection
what does that mean?
Does it use KVM or XEN? there were beta saying it uses XEN since it has GPU passthrough which is great.
Surely btrfs protects against bitrot?no built-in bitrot protection.
It does, and it's certainly better than ReiserFS or XFS. Also, a COW filesystem can prevent corruption of unsynced data. But, btrfs is still limited in it's recovery ability in UnRAID because it's a filesystem applied to each individual disk vs. a typical btrfs array. Unless you enable multiple copies per disk, btrfs can detect the error, but not always repair it. That's why having bitrot protection at the array level is a bit more helpful to actually repair the corruption.Surely btrfs protects against bitrot?
So...then UnRAID does support bitrot protection, as you can use btrfs as the file system. Of course, xfs is the other option, reiserfs is now depreciated in v6.It does, and it's certainly better than ReiserFS or XFS. Also, a COW filesystem can prevent corruption of unsynced data. But, btrfs is still limited in it's recovery ability in UnRAID because it's a filesystem applied to each individual disk vs. a typical btrfs array. Unless you enable multiple copies per disk, btrfs can detect the error, but not always repair it. That's why having bitrot protection at the array level is a bit more helpful to actually repair the corruption.
UnRAID applies the filesystem to individual disks, and as result, and will not provide the ability to recover from bitrot, only report that it found it. So, it doesn't take full advantage of the bitrot protection that btrfs provides (since it can detect, but not repair the error). As a sidenote, I also wonder how many UnRAID users with btrfs backed disks actually schedule scrubs for their data disks. Finally, since UnRAID uses realtime parity calculations, corruption could could be transferred to the parity disk before being detected by an individual disk scrub thus preventing the user to restore a previous, uncorrupted version of the file.So...then UnRAID does support bitrot protection, as you can use btrfs as the file system. Of course, xfs is the other option, reiserfs is now depreciated in v6.
I think, you can have bitrot protectio for single drive on btrfs without manually run scrubbingUsing btrfs in single-disk mode will not give you bitrot protection - you basically get bitrot detection. Theoretically UnRAID could use the detection provided by btrfs to then do a rebuild/repair using its own parity data, but I suspect they are not doing that. You would probably have to manually (or with a scheduled job) run btrfs scrubs on each drive to monitor for bitrot, and if any files are found corrupt then delete them and allow UnRAID to rebuild them from its parity.
You are absolutely correct. As I wrote above, if you you enable multiple copies per disk, you can recover data from bitrot. But, this makes duplicate copies on the individual disk and halves the disk space available per disk. Also, I would bet that almost no one using UnRAID + btrfs is doing this.I think, you can have bitrot protectio for single drive on btrfs without manually run scrubbing
run this when creating btrfs partition or a whole disk: mkfs.btrfs -d dup -m dup -M <device>
Probably can get away without the dual Xeon E5's then .Ok, that's pretty cool... the videos. Now I'll have to build a dual-head web-browsing machine.
I won't touch unRAID.I am still hunting for the binary for v6 ... seems like they don't really care about GPL violations much.
... it is inside the installed directory, which requires agreeing to the EULA... and its not the entire source, even though the entire sources uses GPL libraries ... interesting.