case-sensitivity and UUID of disks w.r.t. multipath.conf

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Hi,

I am running RHEL 7.3 (x86-64) as follows:

[root@archx524lm1 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.3 (Maipo)

[root@archx524lm1 ~]# uname -a
Linux archx524lm1 3.10.0-514.6.1.el7.x86_64 #1 SMP Sat Dec 10 11:15:38 EST 2016 x86_64 x86_64 x86_64 GNU/Linux

The qn is : whatever uuid one plugs in the multipath section of multipath.conf (to define alias), is it case-sensitive ?

For e.g., my storage provides the UUID as 600507680C82025B0000000000000144
which when mapped to RHEL 7.3 host as 3600507680c82025b0000000000000144 // Note lower-case

If I plug-in the following stanza in /etc/multipath.conf

multipaths {
multipath {
wwid 3600507680C82025B0000000000000144
alias MY_VOL_1
}
}
// This does NOT generate /dev/mapper/MY_VOL_1 but generates default name /dev/mapper/mpath

Then if I regenerate the map via "multipath -v 4", it does NOT apply the defined alias MY_VOL_1 for the LUN. But if I change the wwid to lower-case "C" and "B" in wwid, then "multipath -v 4" followed by "mulipath -ll" does list the defined alias as expected.

multipaths {
multipath {
wwid 3600507680c82025b0000000000000144
alias MY_VOL_1
}
}
// This will generate /dev/mapper/MY_VOL_1 device name as expected

So should we convert the upper-case letters provided for LUN from by our storage to lower-case before I plug them into /etc/multipath.conf for generating alias on RHEL 7.3 host ?

Will appreciate your feedback.

Thanks,
Dharmesh.

DK

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