2009/7/9 Win Htin <[email protected]>:
> Thanks Krzysztof . I modified my /etc/multipath.conf file as per your
> suggestion/example but after the reboot the server goes into single
> user mode. Careful examination points to the fact that I forgot to
> delete the line ` wwid "*" ` in the blacklist definition. Need to
> fix that problem and get back with the final outcome.
>
> Cheers,
> Win
Did you resolve this?
I have never been able to get SAN-boot multi-path working on IBM
DS4000 storage. Even _with_ RDAC.
>
>> The preffered path means, that it's not entirely an Active/Active
>> configuration.
>> You probably have LUNs on both controllers - and - system can see LUNs
>> thru both of them, but only one path (controller) is ready to be active
>> and send/receive data.
>>
>> Before RHEL 5 you should use IBM RDAC driver (configuration was simple).
>> Now RDAC implementation is in device-multipathing.
>>
>> You should see the the
>> /usr/share/doc/device-mapper-multipath-0.4.7/multipath.conf.defaults and
>> look for device configuration:
>>
>> device {
>> vendor "IBM"
>> product "1722-600"
>> [...]
>> }
>>
>>
>> We currently use:
>>
>> device {
>> # for DS4700
>> vendor "IBM"
>> product "1722-600"
>> prio_callout "/sbin/mpath_prio_rdac /dev/%n"
>> features "1 queue_if_no_path"
>> hardware_handler "1 rdac"
>> failback immediate
>> rr_weight uniform
>> no_path_retry 300
>> path_checker rdac
>> }
>>
>> With defaults:
>>
>> defaults {
>> udev_dir /dev
>> getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
>> path_checker rdac
>> rr_min_io 1000
>> max_fds 8192
>> user_friendly_names yes
>> }
>>
>> The preffered path is changed by a array if there is no way to use the
>> chosen prefferd path. RHEL is choosing the right path with the priorities
>> (prio_callout "/sbin/mpath_prio_rdac /dev/%n").
>>
>> BTW:
>> You can have all active paths on DS8xxx but not on DS4xxx series.
>>
>> Best Regards
>> Krzysztof Mazurek
>>
>>
>> [email protected] -- zapisano w dniu 2009-07-08 14:32:55:
>>
>>> Win Htin <[email protected]>
>>> Wysłane przez: [email protected]
>>>
>>> 2009-07-08 14:32
>>>
>>> Odpowiedz użytkownikowi
>>> "Red Hat Enterprise Linux 5 \(Tikanga\) discussion mailing-list"
>>> <[email protected]>
>>>
>>> Do
>>>
>>> [email protected]
>>>
>>> DW
>>>
>>> Temat
>>>
>>> [rhelv5-list] Dynamic Multipathing boot disks - Part 2
>>>
>>> Hi folks,
>>>
>>> Thanks to Tom's help, I have Dynamic Multipathing up and running for
>>> my boot disks.
>>>
>>> My next question is, how can I configure the boot disk to stay on the
>>> controller that I specify? Currently, the Storage Array (IBM DS4700,
>>> Active/Active controllers) starts complaining the logical drive is not
>>> on preferred path (controller A). If I change the preferred path back
>>> to controller A, it immediately goes back to controller B. For the
>>> other servers, I have modified QLogic driver installed kernels and
>>> assign preferred paths through qlremote/SanSurfer combo.
>>>
>>> Your help is much appreciated. TIA.
>>>
>>> Cheers,
>>> Win
>>>
>>> _______________________________________________
>>> rhelv5-list mailing list
>>> [email protected]
>>> https://www.redhat.com/mailman/listinfo/rhelv5-list
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