Re: device mapper / multipath

[Adarsh <adarshanto@xxxxxxxxx>]

Hello,

Please note that when I remove a LUN, I will follow the "Clean Device Removal"

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Online_Storage_Reconfiguration_Guide/removing_devices.html

However, sometimes people won't  follow those steps.

I want to handle such scenarios gracefully.

regards,

Adarsh.

On 27 April 2012 12:58, Adarsh <adarshanto@xxxxxxxxx> wrote:

Hello,

I am trying to setup a RH Linux multipath setup with 256 LUNs.

I am facing an issue.

After deleting a LUN, I am invoking "multipath" command to immediately update the MPIO database.

However, it takes 30-40 minutes mostly.

Kindly advice how I can reduce the time taken to a few minutes at the max.

Also, how often does multipathd update the MPIO database.

Basically, I am trying to remove the stale LUN as soon as possible from the database (say 5-8 seconds)

Is there any way to ensure/force that.

Any help will be really appreciated.

regards,

Adarsh.

Setup:

=====

RHEL 5.6 (Linux x336-207-59 2.6.18-238.9.1.el5)

Multipath tools: 0.4.7

multipath.conf:

============

defaults {

        user_friendly_names     no

        max_fds                max

        queue_without_daemon   no

        pg_prio_calc           avg

        flush_on_last_del      yes

}

blacklist {

        wwid                   SIBM-ESXSMAW3073NC_FDAR9P6402P4G

        wwid                   SIBM-ESXSMAW3073NC_FDAR9P6402PU9

        devnode                "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"

        devnode                "^hd[a-z]"

        devnode                "^cciss.*"

}

devices {

        device {

                vendor "NETAPP"

                product "LUN"

                getuid_callout "/sbin/scsi_id -g -u -s /block/%n"

                prio_callout "/sbin/mpath_prio_alua /dev/%n"

                hardware_handler "0"

                failback immediate

                flush_on_last_del yes

        }

}

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