Comment by quantummkv
6 years ago
> There are no (stable) alternatives. BTRFS certainly not, as it's "under heavy development"¹ (since... forever).
Unless you are living in 2012 on a RHEL/CENTOS 6/7 machine, btrfs has been stable for way too long. I have been using btrfs as the sole filesystem on my laptop in standard mode, on my desktop as RAID0 and my NAS as RAID1 for more that two years. I have experienced absolutely zero data loss. Infact, btrfs recovered my laptop and desktop from broken package updates many times.
You might have had some issues when you tried btrfs on distros like RHEL that did not backport the patches to their stable versions because they don't support btrfs commercially. Try something like openSUSE that backports btrfs patches to stable versions or use something like arch.
> That's true, however, the amount is breakage is no different from any other out-of-tree module, and it unlikely to happen with a patch version of a working kernel (in fact, it happen with the 5.0 release).
This is a filesystem that we are talking. In no circumstances will any self respecting sysadmin use a file system that has even a small change of breaking with a system update.
I also used btrfs not too long ago in RAID1. I had a disk failure and voila, the array would be read-only from now on and I would have to recreate it from scratch and copy data over. I even utilized the different data recovery methods (at some point the array would not be mountable no matter what) and in the end that resulted in around 5% of the data being corrupt. I won't rule out my own stupidity in the recovery steps, but after this and the two other times when my RAID1 array went read-only _again_ I just can't trust btrfs for anything other than single device DUP mode operation.
Meanwhile ZFS has survived disk failures, removing 2 disks from an 8 disk RAIDZ3 array and then putting them back, random SATA interface connection issues that were resolved by reseating the HDD, and will probably survive anything else that I throw at it.
I believe he's referring to the raid 5/6 issues
RAID 5/6 issue is the write hole, which is common to all software RAID 5/6 implementations. If it is a problem for you, use either BBU or UPS.
RAIZ/Z2 avoids the issue by having slightly different semantics. That's why it is Z/Z2, not 5/6.