W dniu 20.07.2024 o 16:47, Mateusz Jończyk pisze: > Hello, > > In my laptop, I used to have two RAID1 arrays on top of NVMe and SATA SSD > drives: /dev/md0 for /boot (not partitioned), /dev/md1 for remaining data (LUKS > + LVM + ext4). For performance, I have marked the RAID component device for > /dev/md1 on the SATA SSD drive write-mostly, which "means that the 'md' driver > will avoid reading from these devices if at all possible" (man mdadm). > > Recently, the NVMe drive started having problems (PCI AER errors and the > controller disappearing), so I removed it from the arrays and wiped it. > However, I have reseated the drive in the M.2 socket and this apparently fixed > it (verified with tests). > > $ cat /proc/mdstat > Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] > md1 : active raid1 sdb5[1](W) > 471727104 blocks super 1.2 [2/1] [_U] > bitmap: 4/4 pages [16KB], 65536KB chunk > > md2 : active (auto-read-only) raid1 sdb6[3](W) sda1[2] > 3142656 blocks super 1.2 [2/2] [UU] > bitmap: 0/1 pages [0KB], 65536KB chunk > > md0 : active raid1 sdb4[3] > 2094080 blocks super 1.2 [2/1] [_U] > > unused devices: <none> > > (md2 was used just for testing, ignore it). > > Today, I have tried to add the drive back to the arrays by using a script that > executed in quick succession: > > mdadm /dev/md0 --add --readwrite /dev/nvme0n1p2 > mdadm /dev/md1 --add --readwrite /dev/nvme0n1p3 > > This was on Linux 6.10.0, patched with my previous patch: > > https://lore.kernel.org/linux-raid/20240711202316.10775-1-mat.jonczyk@xxxxx/ > > (which fixed a regression in the kernel and allows it to start /dev/md1 with a > single drive in write-mostly mode). > In the background, I was running "rdiff-backup --compare" that was comparing > data between my array contents and a backup attached via USB. > > This, however resulted in mayhem - I was unable to start any program with an > input-output error, etc. I used SysRQ + C to save a kernel log: > Hello, It is possible that my second SSD has some problems and high read activity during RAID resync triggered it. Reads from that drive are now very slow (between 10 - 30 MB/s) and this suggests that something is not OK. Greetings, Mateusz
