One path missing in disk map on multipath device

Showing a particular case:

The disk mpath5 was only showing one path

root@linux:~ # multipath -ll mpath5
mpath5 (350002ac19430374a) dm-17 3PARdata,VV
[size=47G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=1][active]
\_ 2:0:0:1 sdh 8:112 [active][ready]

The disk used by operating system is cciss/c0d0

root@linux:~ # pvs
PV VG Fmt Attr PSize PFree
/dev/cciss/c0d0p3 vg00 lvm2 a– 269.47G 203.28G
/dev/mpath/350002ac19429374a vgapp lvm2 a– 100.00G 0
/dev/mpath/350002ac1942c374a vgapp lvm2 a– 20.00G 0
/dev/mpath/350002ac1942e374a vgapp lvm2 a– 75.00G 0
/dev/mpath/350002ac1942f374a vgapp lvm2 a– 158.00G 0
/dev/mpath/350002ac19430374a vgapp lvm2 a– 47.00G 996.00M
/dev/mpath/350002ac22869374a vgapp lvm2 a– 100.00G 0
/dev/mpath/350002ac2286a374a vgapp lvm2 a– 40.00G 0

Listing the SCSI devices. sda through sdn are used

root@linux:~ # lsscsi
[1:0:0:1] disk 3PARdata VV 3213 /dev/sda
[1:0:0:2] disk 3PARdata VV 3213 /dev/sdb
[1:0:0:3] disk 3PARdata VV 3213 /dev/sdc
[1:0:0:4] disk 3PARdata VV 3213 /dev/sdd
[1:0:0:5] disk 3PARdata VV 3213 /dev/sde
[1:0:0:6] disk 3PARdata VV 3213 /dev/sdf
[1:0:0:7] disk 3PARdata VV 3213 /dev/sdg
[1:0:0:254] enclosu 3PARdata SES 3213 –
[2:0:0:1] disk 3PARdata VV 3213 /dev/sdh
[2:0:0:2] disk 3PARdata VV 3213 /dev/sdi
[2:0:0:3] disk 3PARdata VV 3213 /dev/sdj
[2:0:0:4] disk 3PARdata VV 3213 /dev/sdk
[2:0:0:5] disk 3PARdata VV 3213 /dev/sdl
[2:0:0:6] disk 3PARdata VV 3213 /dev/sdm
[2:0:0:7] disk 3PARdata VV 3213 /dev/sdn
[2:0:0:254] enclosu 3PARdata SES 3213 –

Checking /etc/multipath.conf. sda was being blacklisted. Commented the line

root@linux:~ # grep -v ^# /etc/multipath.conf

blacklist {
devnode “^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*”
devnode “^hd[a-z][[0-9]*]”
devnode “^hd[a-z]”
#devnode “^sda$”
}

defaults {
user_friendly_names yes
}

Running multipath -v3

root@linux:~ # multipath -v3

Checking disk mpath5

root@linux:~ # multipath -ll mpath5
mpath5 (350002ac19430374a) dm-17 3PARdata,VV
[size=47G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=1][active]
\_ 1:0:0:1 sda 8:0 [active][ready]
\_ 2:0:0:1 sdh 8:112 [active][ready]

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