Unfortunately i have been subject to a disk failure. After trying to delete the disk, and being unable to delete it, i asked on the BTRFS mailing list. Here i was pointed to a couple of patches which will detect I/O errors and allow switching to a redundant disk.
As i already had a crash on another PC on friday using btrfs, where i unmounted the disks shut down and replaced the disk. Even though it was RAID 5 i was unable to recover any data, fortunately it was all temporary data. So i wiped the disks.
How can i make sure this doesn’t happen again? As recompiling the kernel would require a reboot, and then i might as well remove the disk and fail it that way.
Does rockstor use patches or just the default kernel and modules if i were to recompile.