On Sat, Aug 1, 2009 at 12:00 PM, <[email protected]> wrote:
> ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 31 Jul 2009 23:37:10 -0400 > From: Vanco Backup <[email protected]> > Subject: Re: [rhelv5-list] Re:Dynamic Multipathing boot disks - Part 2 > To: "Red Hat Enterprise Linux 5 (Tikanga) discussion mailing-list" > <[email protected]> > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=ISO-8859-2 > > 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. I never had issues with SAN booting IBM blade servers from either DS3400 or DS4700 arrays. I'm using QLogic HBAs. Used to customize the FC paths through QLogic's "qlremote" application and rebuild custom kernel. Was testing DM-pathing to get away from the custom kernel approach. What particular problems do you have? Cheers, Win >>> 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 _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
