Partitions on `sd` devices are not getting detected in RHEL6/7 after reboot when multipathd is used
Issue
- When we create partition on multipath device, partitions on underlying
sddevices are seen missing. -
Partitions on
/dev/sddevices are not getting detected after reboot. -
Multipath devices:
mpathc (36000d310000065000000000000001f0f) dm-0 COMPELNT,Compellent Vol
size=1.0G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='service-time 0' prio=1 status=active
|- 0:0:5:2 sdf 8:80 active ready running
|- 0:0:6:2 sdg 8:96 active ready running
|- 7:0:4:2 sdl 8:176 active ready running
`- 7:0:6:2 sdm 8:192 active ready running
- Multipath device links:
lrwxrwxrwx. 1 0 0 10 Feb 13 16:21 dm-name-mpathc -> ../../dm-0
lrwxrwxrwx. 1 0 0 10 Feb 13 16:21 dm-name-mpathc1 -> ../../dm-1
- Underlying multipath devices:
# cat proc/partitions |egrep "sdf|sdg|sdl|sdm"
8 80 1048576 sdf
8 96 1048576 sdg
8 176 1048576 sdl
8 192 1048576 sdm
- Device list in
/devdirectory:
# less sos_commands/block/ls_-lanR_.dev |egrep "sdf|sdg|sdl|sdm"
brw-rw----. 1 0 6 8, 80 Feb 13 16:21 sdf
brw-rw----. 1 0 6 8, 96 Feb 13 16:21 sdg
brw-rw----. 1 0 6 8, 176 Feb 13 16:21 sdl
brw-rw----. 1 0 6 8, 192 Feb 13 16:21 sdm
lrwxrwxrwx. 1 0 0 6 Feb 13 16:21 8:176 -> ../sdl
lrwxrwxrwx. 1 0 0 6 Feb 13 16:21 8:192 -> ../sdm
lrwxrwxrwx. 1 0 0 6 Feb 13 16:21 8:80 -> ../sdf
lrwxrwxrwx. 1 0 0 6 Feb 13 16:21 8:96 -> ../sdg
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 scsi-36000d310000065000000000000001f0f -> ../../sdm
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 wwn-0x6000d310000065000000000000001f0f -> ../../sdf
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 pci-0000:41:00.0-fc-0x5000d31000006505-lun-2 -> ../../sdg
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 pci-0000:41:00.0-fc-0x5000d31000006506-lun-2 -> ../../sdf
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 pci-0000:41:00.1-fc-0x5000d31000006507-lun-2 -> ../../sdm
lrwxrwxrwx. 1 0 0 9 Feb 13 16:21 pci-0000:41:00.1-fc-0x5000d31000006508-lun-2 -> ../../sdl
-
However partitions are getting detected as showed in the following command outputs:
fdisk:
# cat sos_commands/block/fdisk_-l_.dev.sdf Disk /dev/sdf: 1073 MB, 1073741824 bytes, 2097152 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 2097152 bytes / 2097152 bytes Disk label type: dos Disk identifier: 0xef3441e5 Device Boot Start End Blocks Id System /dev/sdf1 4096 2097151 1046528 83 Linuxparted:
# cat sos_commands/block/parted_-s_.dev.sdf_print Model: COMPELNT Compellent Vol (scsi) Disk /dev/sdf: 1074MB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 2097kB 1074MB 1072MB primarydmesg:
# sos_commands/kernel/dmesg [ 5.145014] sdg: sdg1 [ 5.145797] sd 0:0:6:2: [sdg] Attached SCSI disk [ 5.151472] sdf: sdf1 [ 5.152291] sd 0:0:5:2: [sdf] Attached SCSI disk [ 7.719176] sd 7:0:4:2: [sdl] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB) [ 7.719620] sd 7:0:4:2: [sdl] Write Protect is off [ 7.719622] sd 7:0:4:2: [sdl] Mode Sense: 8f 00 00 08 [ 7.719735] sd 7:0:4:2: [sdl] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 7.723910] sd 7:0:6:2: [sdm] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB) [ 7.724320] sd 7:0:6:2: [sdm] Write Protect is off [ 7.724322] sd 7:0:6:2: [sdm] Mode Sense: 8f 00 00 08 [ 7.724434] sd 7:0:6:2: [sdm] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 7.734991] sdm: sdm1 [ 7.735803] sd 7:0:6:2: [sdm] Attached SCSI disk [ 7.745098] sdl: sdl1/var/log/messageslogs:
Feb 13 16:21:08 ora5 kernel: sdf: sdf1
Environment
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 6
- DM Multipath
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