Hi Miroslaw, I finally got around to trying this out. I reproduced on:
Focal with 5.4.0-200-generic Jammy with 5.15.0-122-generic Noble with 6.8.0-49-generic Plucky with 6.12.0-3-generic They all behave the same, and they all behave as you report in the bug report. I will note that every dmesg will report that the underlying disk is offline: [ 108.055848] I/O error, dev sda, sector 2048 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.056279] Buffer I/O error on dev dm-0, logical block 0, lost async page write [ 108.056612] Buffer I/O error on dev dm-0, logical block 1, lost async page write [ 108.056996] Buffer I/O error on dev dm-0, logical block 2, lost async page write [ 108.057335] Buffer I/O error on dev dm-0, logical block 3, lost async page write [ 108.057694] Buffer I/O error on dev dm-0, logical block 4, lost async page write [ 108.058013] Buffer I/O error on dev dm-0, logical block 5, lost async page write [ 108.058342] Buffer I/O error on dev dm-0, logical block 6, lost async page write [ 108.058703] Buffer I/O error on dev dm-0, logical block 7, lost async page write [ 108.059023] Buffer I/O error on dev dm-0, logical block 8, lost async page write [ 108.059359] Buffer I/O error on dev dm-0, logical block 9, lost async page write [ 108.060034] I/O error, dev sda, sector 2304 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.060549] I/O error, dev sda, sector 2560 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.061012] I/O error, dev sda, sector 2816 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.061465] I/O error, dev sda, sector 3072 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.061908] I/O error, dev sda, sector 3328 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.062318] I/O error, dev sda, sector 3584 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.062744] I/O error, dev sda, sector 3840 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.063188] I/O error, dev sda, sector 4096 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 [ 108.063616] I/O error, dev sda, sector 4352 op 0x1:(WRITE) flags 0x104000 phys_seg 32 prio class 0 Its just that dd succeeds, and exits 0. A bit frustrating I suppose. Since this affects the very latest mainline, we should probably ask upstream about it. Will you write to the upstream device mapper maintainers? Thanks, Matthew -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2084979 Title: Device Mapper accepts writes even when the underlying devices are dead (offline or transport-offline) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2084979/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs