[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [dm-devel] Multipathing using device mapper howto?

Bruen, Mark wrote:

I'm just beginning to look at device mapper to multipath SAN luns. I've been searching for some time and can't find a simple reference on how to create the multipathed devices from the same luns presented to two or more HBA paths. Is there a source for that information?

dm-devel mailing list
dm-devel redhat com

I don't know of any external sources, but the quick and dirty way is to first fdisk your /dev/sd devices, and then edit your /etc/multipath.conf file and comment out hte lines

devnode_blacklist {
       devnode "*"

and then uncomment out the lines

defaults {
       multipath_tool  "/sbin/multipath -v0"
       udev_dir        /dev
       polling_interval 10
       default_selector        "round-robin 0"
       default_path_grouping_policy    multibus
       default_getuid_callout  "/sbin/scsi_id -g -u -s /block/%n"
       default_prio_callout    "/bin/true"
       default_features        "0"
       rr_wmin_io              100
       failback                immediate

Then reboot, and it should work. You're devices should show up in /dev/dm-#, then all you want to do is do a kpartx -a on /dev/dm-# and it will create a new /dev/dm-#+1 for the partitions (ie if my disk was /dev/dm-0 and i had one partition, and i ran kpartx -a i would get /dev/dm-1. its equivalent of /dev/sda and /dev/sda1). Thank you,


Josef Whiter, RHCE
Global Support Services
Red Hat, Inc.
919-754-3700 x44429

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]