I constructed a 1-copy mirror with the following commands: # pvcreate --metadatasize 192k /dev/sdcn /dev/sdfj /dev/sdfa Physical volume "/dev/sdcn" successfully created Physical volume "/dev/sdfj" successfully created Physical volume "/dev/sdfa" successfully created # vgcreate vg /dev/sdcn /dev/sdfj /dev/sdfa Volume group "vg" successfully created # lvcreate -L 32g -m 1 -n lv vg Logical volume "lv" created The status showed: # lvs -a -o +devices LV VG Attr LSize Origin Snap% Move Log Copy% Convert Devices lv vg mwi-a- 32.00G lv_mlog 29.72 lv_mimage_0(0),lv_mimage_1(0) [lv_mimage_0] vg Iwi-ao 32.00G /dev/sdcn(0) [lv_mimage_1] vg Iwi-ao 32.00G /dev/sdfj(0) [lv_mlog] vg lwi-ao 4.00M /dev/sdfa(0) Then I forced /dev/sdfj to fail (removing the unit from the FC SAN), and the state of the mirror went to: # lvs /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv vg -wi-a- 32.00G At this point I know I can do: # vgreduce -a vg /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error Physical volume "/dev/sdcn" still in use Removed "/dev/sdfa" from volume group "vg" But I run into two problems: (1) I'd like to be able to live without the constant errors about /dev/sdfj, and tried: # pvremove -f /dev/sdfj /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error No physical volume label read from /dev/sdfj /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error Labels on physical volume "/dev/sdfj" successfully wiped but that didn't stop it. and: (2) I'd like to be able to recreate the 1-copy mirror from the currently linear volume, but can't (easily): # pvcreate --metadatasize 192k /dev/sdp Physical volume "/dev/sdp" successfully created # vgextend vg /dev/sdp ... errors from sdfj omitted... Volume group "vg" successfully extended # vgs /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error VG #PV #LV #SN Attr VSize VFree vg 2 1 0 wz--n- 542.67G 510.67G # lvconvert -m 1 /dev/vg/lv /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error Insufficient suitable allocatable extents for logical volume : 8192 more required Unable to allocate extents for mirror(s). I can use the alloc anywhere options, but I'm at a loss as to why that's needed: # lvconvert -m1 --alloc anywhere /dev/vg/lv /dev/sdfj: read failed after 0 of 2048 at 0: Input/output error /dev/vg/lv: Converted: 1.3% /dev/vg/lv: Converted: 2.6% /dev/vg/lv: Converted: 3.8% ... Any pointers on how to remove /dev/sdfj from the scan (other than, I guess, updated /etc/lvm.conf to filter it out) or an explanation as to why the 'alloc anywhere' is needed for the lvconvert would be muchly appreciated. Alan D. Brunelle Hewlett-Packard -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
