How could I force minor number allocation for SAN on linux?

I've got a cluster both attached to a SAN (using multipath on linux), using RAW devices for ORACLE.

When each box boot they pick开发者_JS百科 up differant minor number (I guess it's first come first serve), seems to be random allocation, not sure I need to find a way to force it. (Used to love my solaris box...). Therefore ORACLE is using minor number and failover will just mean loosing all the data!

How could I force minor number allocation for SAN on linux?

You can set up user_friendly_names yes stanza in your multipath.conf file and enumerate all multipath devices on both nodes of your Oracle cluster:

multipaths {
        multipath {
                # LUN 123 on your array
                alias   ora01
                wwid    36006abcdefabcdef0123456789abcdef1
        }
}

Give to Oracle ASM the paths to customized names of your disks (/dev/mapper/ora01 in this example) and both cluster nodes will see the same disk with very same name.

wwid begins with 3 followed by WWN of your SAN disk (refer to documentation of your SAN vendor how to get these numbers...)