* Multipath and SAN Fabric failover
@ 2006-09-07 17:39 John Little
2006-09-07 18:09 ` Bernd Zeimetz
0 siblings, 1 reply; 3+ messages in thread
From: John Little @ 2006-09-07 17:39 UTC (permalink / raw)
To: dm-devel
Hi all,
I am trying to setup our server so that we have fabric failover from
the san. However my file sytem comes up read-only when I pull a cable
for testing.
I am using the following:
SLES 10
multipath-tools-0.4.6-25.8
q-logic 2342 dual port hba
emc cx600 san
(4) McData DS-24 switches (2 for fabric a and 2 for fabric b)
I have one port from the hba plugged into fabric a and the other
plugged into fabric b.
multipath -v2 -d before failover gives the following:
xen2:~ # multipath -v2 -d
create: SSEAGATE_ST973401LSUN72G0910FQL9_3LB0FQL9SEAGATE,ST973401LSUN72G
[size=68G][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][undef]
\_ 0:2:0:0 sda 8:0 [undef][ready]
SSEAGATE_ST973401LSUN72G0910FPHE_3LB0FPHESEAGATE,ST973401LSUN72G
[size=68G][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][undef]
\_ 0:3:1:0 sdb 8:16 [active][ready]
capsprod (360060160f06109004352b218eb51da11) DGC,RAID 5
[size=50G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=1][undef]
\_ 1:0:0:0 sdc 8:32 [active][ready]
\_ round-robin 0 [prio=1][undef]
\_ 1:0:1:0 sde 8:64 [active][ready]
360060160f0610900ea604e9d2412db11DGC,RAID 5
[size=58G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=2][undef]
\_ 1:0:0:1 sdd 8:48 [active][ready]
\_ 1:0:1:1 sdf 8:80 [active][ready]
capsprod (360060160f06109004352b218eb51da11) DGC,RAID 5
[size=50G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=1][undef]
\_ 1:0:0:0 sdc 8:32 [undef][ready]
\_ round-robin 0 [prio=1][undef]
\_ 1:0:1:0 sde 8:64 [undef][ready]
360060160f0610900ea604e9d2412db11DGC,RAID 5
[size=58G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=2][undef]
\_ 1:0:0:1 sdd 8:48 [undef][ready]
\_ 1:0:1:1 sdf 8:80 [undef][ready]
The disc that I'm using for test has the alias capsprod.
When I pull the cable from fabric a multipath -v2 -d gives:
xen2:~ # multipath -v2 -d
sdc: checker msg is "emc_clariion_checker: query command indicates
error"
error calling out /sbin/scsi_id -g -u -s /block/sdc
sdd: checker msg is "emc_clariion_checker: query command indicates
error"
error calling out /sbin/scsi_id -g -u -s /block/sdd
sde: checker msg is "emc_clariion_checker: query command indicates
error"
error calling out /sbin/scsi_id -g -u -s /block/sde
sdf: checker msg is "emc_clariion_checker: query command indicates
error"
error calling out /sbin/scsi_id -g -u -s /block/sdf
create: SSEAGATE_ST973401LSUN72G0910FQL9_3LB0FQL9SEAGATE,ST973401LSUN72G
[size=68G][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][undef]
\_ 0:2:0:0 sda 8:0 [undef][ready]
SSEAGATE_ST973401LSUN72G0910FPHE_3LB0FPHESEAGATE,ST973401LSUN72G
[size=68G][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][undef]
\_ 0:3:1:0 sdb 8:16 [active][ready]
sdc: checker msg is "emc_clariion_checker: query command indicates
error"
sde: checker msg is "emc_clariion_checker: query command indicates
error"
capsprod (360060160f06109004352b218eb51da11) DGC,RAID 5
[size=50G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:0:0 sdc 8:32 [failed][faulty]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:1:0 sde 8:64 [failed][faulty]
sdd: checker msg is "emc_clariion_checker: query command indicates
error"
sdf: checker msg is "emc_clariion_checker: query command indicates
error"
360060160f0610900ea604e9d2412db11DGC,RAID 5
[size=58G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:0:1 sdd 8:48 [failed][faulty]
\_ 1:0:1:1 sdf 8:80 [failed][faulty]
sdc: checker msg is "emc_clariion_checker: query command indicates
error"
sde: checker msg is "emc_clariion_checker: query command indicates
error"
capsprod (360060160f06109004352b218eb51da11) DGC,RAID 5
[size=50G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:0:0 sdc 8:32 [undef][faulty]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:1:0 sde 8:64 [undef][faulty]
sdd: checker msg is "emc_clariion_checker: query command indicates
error"
sdf: checker msg is "emc_clariion_checker: query command indicates
error"
360060160f0610900ea604e9d2412db11DGC,RAID 5
[size=58G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=0][undef]
\_ 1:0:0:1 sdd 8:48 [undef][faulty]
\_ 1:0:1:1 sdf 8:80 [undef][faulty]
/etc/multipath.conf has the following entries:
xen2:~ # grep -v "#" /etc/multipath.conf
defaults {
udev_dir /dev
polling_interval 10
selector "round-robin 0"
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout /bin/true
failback immediate
}
devnode_blacklist {
device {
vendor SEAGATE
product ST973401LSUN72G
}
}
multipaths {
multipath {
wwid 360060160f06109004352b218eb51da11
alias capsprod
path_grouping_policy failover
path_checker readsector0
path_selector "round-robin 0"
failback immediate
}
}
Can someone point me in the right direction to get this resolved?
Best regards,
John Little, Network Systems
Hendricks Regional Health
http://hendrickshospital.org
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Multipath and SAN Fabric failover
2006-09-07 17:39 Multipath and SAN Fabric failover John Little
@ 2006-09-07 18:09 ` Bernd Zeimetz
0 siblings, 0 replies; 3+ messages in thread
From: Bernd Zeimetz @ 2006-09-07 18:09 UTC (permalink / raw)
To: device-mapper development
Heya,
I think you should just try an empty multipath.conf, only put the
blacklist in. The EMC CX needs pp_emc as prio callout for example. The
defaults within multipath should just work.
Also make sure your failovermode and arraycommpath are both set to 1. A
few hints are mentioned on
http://christophe.varoqui.free.fr/wiki/wakka.php?wiki=TestedEnvironments
Please fill in if you find something that's missing there.
Best regards,
Bernd Zeimetz
John Little wrote:
> Hi all,
>
> I am trying to setup our server so that we have fabric failover from
> the san. However my file sytem comes up read-only when I pull a cable
> for testing.
>
> I am using the following:
> SLES 10
> multipath-tools-0.4.6-25.8
> q-logic 2342 dual port hba
> emc cx600 san
> (4) McData DS-24 switches (2 for fabric a and 2 for fabric b)
>
>
>
> /etc/multipath.conf has the following entries:
>
> xen2:~ # grep -v "#" /etc/multipath.conf
> defaults {
> udev_dir /dev
> polling_interval 10
> selector "round-robin 0"
> getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
> prio_callout /bin/true
> failback immediate
> }
> devnode_blacklist {
> device {
> vendor SEAGATE
> product ST973401LSUN72G
> }
> }
> multipaths {
> multipath {
> wwid 360060160f06109004352b218eb51da11
> alias capsprod
> path_grouping_policy failover
> path_checker readsector0
> path_selector "round-robin 0"
> failback immediate
> }
> }
>
> Can someone point me in the right direction to get this resolved?
>
> Best regards,
> John Little, Network Systems
> Hendricks Regional Health
> http://hendrickshospital.org
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Multipath and SAN Fabric failover
@ 2006-09-08 15:32 John Little
0 siblings, 0 replies; 3+ messages in thread
From: John Little @ 2006-09-08 15:32 UTC (permalink / raw)
To: dm-devel
Hi Bernd
I commented out everything including the blacklist in the multipath.conf as you suggested. When I unplug the fc cable from fabric a the filesystem goes into read only mode. multipath -v2 -d shows the same errors previously noted. After rebooting I unplugged the fc cable from fabric b. The file system properly stays in read\write mode.
Just to make sure that I've covered everything I partitioned the disk as /dev/sdc and then used lvm2 command: pvcreate /dev/disk/by-name/capsprod-part1 to initialize and use the partition with lvm.
I found the following error in dmesg:
device-mapper: 4.5.0-ioctl (2005-10-04) initialised: dm-devel@redhat.com
dm-netlink version 0.0.2 loaded
device-mapper: dm-multipath version 1.0.4 loaded
device-mapper: dm-round-robin version 1.0.0 loaded
device-mapper: dm-multipath: error getting device<====error
device-mapper: error adding target to table<====error
device-mapper: dm-emc version 0.0.3 loaded
device-mapper: dm-emc: long trespass command will be send
device-mapper: dm-emc: honor reservation bit will not be set (default)
device-mapper: dm-emc: long trespass command will be send
device-mapper: dm-emc: emc_pg_init: sending switch-over command
device-mapper: dm-emc: honor reservation bit will not be set (default)
device-mapper: dm-emc: emc_pg_init: sending switch-over command
Can you give me an idea of what else to check? I'm nowhere near an expert on this subject as just about everything I've learned has been from reading this list.
A couple of questions come to mind:
Is the lun not properly trespassing from fabric a to fabric b?
Where does the directive [features=1 queue_if_no_path] come from when
running multipath -v2 -d? Could this be the problem?
Thanks,
John
>Heya,
>I think you should just try an empty multipath.conf, only put the blacklist in. The EMC CX needs pp_emc as prio callout for example. The defaults within >multipath should just work. Also make sure your failovermode and arraycommpath are both set to 1. A few hints are mentioned on >http://christophe.varoqui.free.fr/wiki/wakka.php?wiki=TestedEnvironments
>Please fill in if you find something that's missing there.
>Best regards,
>Bernd Zeimetz
>>John Little wrote:
>> Hi all,
>> I am trying to setup our server so that we have fabric failover from
>> the san. However my file sytem comes up read-only when I pull a cable
>> for testing.
>> I am using the following:
>> SLES 10
>> multipath-tools-0.4.6-25.8
>> q-logic 2342 dual port hba
>> emc cx600 san
>> (4) McData DS-24 switches (2 for fabric a and 2 for fabric b)
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-09-08 15:32 UTC | newest]
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2006-09-07 17:39 Multipath and SAN Fabric failover John Little
2006-09-07 18:09 ` Bernd Zeimetz
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2006-09-08 15:32 John Little
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