LUN device file names mixed

Question

The following listings are from a Linux RHEL box. I'm a bit confused over the following inconsistencies.

Here we have aliases defined for each LUN in multipath bindings file:

mpath0 36006016071602e0026025fa3eff2e111
mpath1 36006016071602e008cec8699eff2e111
mpath2 36006016071602e00485dffadeff2e111
mpath3 360060160b6502e00e63f011ab359e211

But here we have WWNs and aliases for device file names. Why the mix?

ll /dev/mpath
lrwxrwxrwx 1 root root 8 Sep 25 17:39 36006016071602e0026025fa3eff2e111 -> ../dm-15
lrwxrwxrwx 1 root root 8 Sep 25 17:39 36006016071602e0026025fa3eff2e111p1 -> ../dm-20
lrwxrwxrwx 1 root root 8 Sep 25 17:39 36006016071602e00485dffadeff2e111 -> ../dm-17
lrwxrwxrwx 1 root root 8 Sep 25 17:39 36006016071602e00485dffadeff2e111p1 -> ../dm-18
lrwxrwxrwx 1 root root 8 Sep 25 17:43 mpath1 -> ../dm-16
lrwxrwxrwx 1 root root 8 Sep 25 17:43 mpath1p1 -> ../dm-19
lrwxrwxrwx 1 root root 8 Jan  8 14:50 mpath3 -> ../dm-27

/etc/multipath.conf has nothing defined that would cause this.
service multipathd restart (and start/stop) have been executed.

multipath -ll
mpath2 (36006016071602e00485dffadeff2e111) dm-17 DGC,VRAID
[size=209G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=1][active]
 \_ 1:0:0:2 sdd 8:48  [active][ready]
\_ round-robin 0 [prio=0][enabled]
 \_ 2:0:0:2 sdg 8:96  [active][ready]
mpath1 (36006016071602e008cec8699eff2e111) dm-16 DGC,VRAID
[size=55G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=1][active]
 \_ 1:0:0:1 sdc 8:32  [active][ready]
\_ round-robin 0 [prio=0][enabled]
 \_ 2:0:0:1 sdf 8:80  [active][ready]
mpath0 (36006016071602e0026025fa3eff2e111) dm-15 DGC,VRAID
[size=9.0G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=1][active]
 \_ 2:0:0:0 sde 8:64  [active][ready]
\_ round-robin 0 [prio=0][enabled]
 \_ 1:0:0:0 sdb 8:16  [active][ready]
mpath3 (360060160b6502e00e63f011ab359e211) dm-27 DGC,VRAID
[size=210G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=1][active]
 \_ 2:0:0:3 sdi 8:128 [active][ready]
\_ round-robin 0 [prio=0][enabled]
 \_ 1:0:0:3 sdh 8:112 [active][ready]

Other systems are consistent:

ll /dev/mpath
lrwxrwxrwx 1 root root 8 Dec 26 12:18 3600601601c902e000ef2100e1e3ee211 -> ../dm-15
lrwxrwxrwx 1 root root 8 Dec 26 12:18 36006016033902e007a63bd7820fce111 -> ../dm-14
lrwxrwxrwx 1 root root 8 Dec 26 12:18 36006016033902e00d2bee6bc1ffce111 -> ../dm-13

ll /dev/mpath
lrwxrwxrwx 1 root root 8 Dec 26 18:47 3600601601c902e000ef2100e1e3ee211 -> ../dm-15
lrwxrwxrwx 1 root root 8 Dec 26 18:47 3600601601c902e00160c21202a07e211 -> ../dm-14
lrwxrwxrwx 1 root root 8 Dec 26 18:47 3600601601c902e003eedbf312a07e211 -> ../dm-13

Thanks in advance,
Xavier

Only 2 stanzas listed in multipath.conf: (blacklist {devnode "sda") AND (defaults {user_friendly_names yes}). — XO01, Jan 11 '13 at 06:30
Default location of /var/lib/multipath/bindings. /var is a mountpoint and Red Hat does recommend relocating it to /-- but I doubt this is an issue. — XO01, Jan 11 '13 at 09:50
Do you reboot server or just restart multipath after binding editing? — dchirikov, Jan 11 '13 at 12:01
Ouch! You gave `ll /dev/mpath`, but what is in your `/dev/mapper`? — dchirikov, Jan 12 '13 at 22:04
'/etc/multipath.conf' is not used on any of the other hosts which are not showing these inconsistencies. Also, I listed '/dev/mpath' for 2 other boxes above-- I do not see this behavior on the hundreds of other servers I have. Just wanting to understand this particular difference. '/dev/mpath' looks normal. — XO01, Jan 14 '13 at 17:35

score 0 · Answer 1 · answered Jan 14 '13 at 19:16

0

Default location of /var/lib/multipath/bindings. /var is a mountpoint and Red Hat does recommend relocating it to /-- but I doubt this is an issue. – XO01 Jan 11 at 9:50

Why do you think that? See, e.g., https://bugzilla.redhat.com/show_bug.cgi?id=357331 Can you set the bindings file to e.g. /etc/multipath.bindings (assuming /etc isn't a separate filesystem). Make sure you have http://rhn.redhat.com/errata/RHBA-2008-0337.html installed.

answered Jan 14 '13 at 19:16

Mark Wagner

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I'm familiar with the link. The symptoms of this problem are different (this config be put in place later). I just discovered the problem (posted below). – XO01 Jan 15 '13 at 20:52

XO01 · Answer 2 · 2013-01-15T23:37:18.367

Not knowing the administrative history on this machine, the issue resulted from LUNs being unrepresented from the system in an unclean manner. Rebooting the system was recommended and resolved the issue.

lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e0026025fa3eff2e111 -> ../dm-15
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e0026025fa3eff2e111p1 -> ../dm-21
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e00485dffadeff2e111 -> ../dm-17
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e00485dffadeff2e111p1 -> ../dm-19
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e008cec8699eff2e111 -> ../dm-16
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e008cec8699eff2e111p1 -> ../dm-20
lrwxrwxrwx 1 root root 8 Jan 15 15:44 36006016071602e00966edb05ab5de211 -> ../dm-18

Tanks for the help everyone

LUN device file names mixed

2 Answers2