dm-multipath, multipath-tools on 8.04

Matthew Ernisse mernisse at ub3rgeek.net
Wed Jul 2 14:46:51 UTC 2008


We are looking to migrate a large application at work onto Ubuntu 
server 8.04 but are having troubles getting dm-multipath to function.

The general layout is a fairly standard multipath fiber channel 
setup. 4x NetApp FAS3070c storage arrays in clustered pairs, each with 
1 FC connection to one each of a pair of Cisco 9124 SAN switches. My 
test client is an IBM x330 attached directly to the 9124s with a 
dual-port Qlogic 2312 PCI-X HBA.

This is a fresh install of 8.04, with nothing else on it on a 36G LUN 
exported on one of the clusters. At boot the lun shows up as 
/dev/sd[a-d]. I installed onto /dev/sda from the -server CD.

I am running kernel 2.6.24-19-server and multipath-tools 0.4.8-7ubuntu2.

My multipath.conf at this point (I have tried with no multipath.conf, 
as well as various incarnations of one based on 
/usr/share/doc/multipath-tools/examples/multipath.conf.synthetic):
----
defaults {
	path_checker	tur
}

multipaths {
	multipath {
		wwid		360a98000486e5770584a4a3944577365
		alias		netapp
	}
}

devices {
	device {
		vendor			"NETAPP  "
		product			"LUN "
	}
}
----

multipath -d outputs:
----
create: netapp (360a98000486e5770584a4a3944577365)  NETAPP  ,LUN           
[size=36G][features=0][hwhandler=0]
\_ round-robin 0 [prio=1][undef]
 \_ 1:0:0:0 sda 8:0   [undef][ready]
\_ round-robin 0 [prio=1][undef]
 \_ 1:0:1:0 sdb 8:16  [undef][ready]
\_ round-robin 0 [prio=1][undef]
 \_ 4:0:0:0 sdc 8:32  [undef][ready]
\_ round-robin 0 [prio=1][undef]
 \_ 4:0:1:0 sdd 8:48  [undef][ready]
----

This seems to indicate after some googling that the dm layer is in an 
unknown state. When multipathd starts at boot, the following is emitted 
to the kernel log ringbuffer:

----
[   97.196268] device-mapper: uevent: version 1.0.3
[   97.196360] device-mapper: ioctl: 4.12.0-ioctl (2007-10-02) initialised: dm-devel at redhat.com
[   97.223509] device-mapper: multipath: version 1.0.5 loaded
[   97.688328] device-mapper: multipath round-robin: version 1.0.0 loaded
[   97.697552] device-mapper: table: 254:0: multipath: error getting device
[   97.697620] device-mapper: ioctl: error adding target to table
[   97.701790] device-mapper: table: 254:0: multipath: error getting device
[   97.701866] device-mapper: ioctl: error adding target to table
[   97.705501] device-mapper: table: 254:0: multipath: error getting device
[   97.705587] device-mapper: ioctl: error adding target to table
[   97.709331] device-mapper: table: 254:0: multipath: error getting device
[   97.709402] device-mapper: ioctl: error adding target to table
[   97.726491] device-mapper: table: 254:0: multipath: error getting device
[   97.726562] device-mapper: ioctl: error adding target to table
[   97.732499] device-mapper: table: 254:0: multipath: error getting device
[   97.732572] device-mapper: ioctl: error adding target to table
[   97.743522] device-mapper: table: 254:0: multipath: error getting device
[   97.743598] device-mapper: ioctl: error adding target to table
[   97.761402] device-mapper: table: 254:0: multipath: error getting device
[   97.761480] device-mapper: ioctl: error adding target to table
[   97.773240] device-mapper: table: 254:0: multipath: error getting device
[   97.773309] device-mapper: ioctl: error adding target to table
[   97.836975] device-mapper: table: 254:0: multipath: error getting device
[   97.837052] device-mapper: ioctl: error adding target to table
[   97.848610] device-mapper: table: 254:0: multipath: error getting device
[   97.848684] device-mapper: ioctl: error adding target to table
[   97.859221] device-mapper: table: 254:0: multipath: error getting device
[   97.859292] device-mapper: ioctl: error adding target to table
[   97.874788] device-mapper: table: 254:0: multipath: error getting device
[   97.874860] device-mapper: ioctl: error adding target to table
[   97.968836] device-mapper: table: 254:0: multipath: error getting device
[   97.968852] device-mapper: ioctl: error adding target to table
[   97.992795] device-mapper: table: 254:0: multipath: error getting device
[   97.992810] device-mapper: ioctl: error adding target to table
[   98.011870] device-mapper: table: 254:0: multipath: error getting device
[   98.011937] device-mapper: ioctl: error adding target to table
[   98.037471] device-mapper: table: 254:0: multipath: error getting device
[   98.037539] device-mapper: ioctl: error adding target to table
----

If I try to load the multipath map manually (eg: sudo multipath -v2) 
the program emits no output, but more lines like above (the table: and 
ioctl: lines) are output to the kernel log.

multipath -ll outputs nothing, there are no device-mapper devices 
registered to the system (no nodes in /dev/mapper other than control, 
nothing listed in dmsetup list)

The only mention of this kind of error that I find is for something 
back in Dapper/Feisty era telling to remove evms. This system has never 
had evms installed on it.

I would be thrilled at any assistance anyone could offer, there isn't 
much google could offer about dm-multipath on ubuntu, or dm-multipath 
in general. It seems to just work for most people.

I am currently trying to replicate this issue on Debian 4.0 (etch).

-- 
Matthew Ernisse
E-Mail: mernisse at ub3rgeek.net
Web: http://www.ub3rgeek.net/                   PGP Key ID: 0x9C4C5013
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