mikebounds
11 years agoLevel 6
udid_mismatch using RHEL5u5 SF6.1 on Virtual Box
For a lab enviroment for testing on my laptop, I have used Virtual Box with RHEL 5.5 with SFHA6.1 and I have shared a disk by creating a disk of "fixed size" and setting type to "Shareable", but I get udid_mismatch as the udid seems to be host (not device) specific:
Host a:
[root@r55v61a ~]# vxdisk list sdc | egrep "guid|udid" guid: {1ac21a9c-a550-11e3-a7fd-30ba236498b6} udid: VBOX%5FHARDDISK%5FOTHER%5FDISKS%5Fr55v61a.localdomain%5F%2Fdev%2Fsdc
Host b:
[root@r55v61b ~]# vxdisk list sdc | egrep "guid|udid" flags: online ready private autoconfig udid_mismatch clone_disk guid: {1ac21a9c-a550-11e3-a7fd-30ba236498b6} udid: VBOX%5FHARDDISK%5FOTHER%5FDISKS%5Fr55v61b.localdomain%5F%2Fdev%2Fsdc
So here you can see that the udid is different between the hosts as it contains the hostname (and device path /dev/sdc which could be different too).
It is the same disk as you can see the guid is the the same and the uuid is the same in the .vbox config file and if I create a diskgroup on one node then I am able to see the diskgroup and mount and write to the filesystem on both nodes.
As I understand, "vxdisk list" is showing me the udid in the Device Discovery Layer and SF writes this udid to the private region and so if for exampe I run "vxdisk updateudid" on one node, then udid_mismatch is fixed on that node, but then of course the other node gets the udid_mismatch.
Note it is the hostname in the udid, NOT the virtual machine name and so if I change the hostname of the server so that both nodes are the same, then this fixes the issue which is sort of a workaround as VCS uses /etc/VRTSvcs/sysname, not the hostname, but having duplicate hostnames may cause other issues.
Looking at http://www.symantec.com/business/support/index?page=content&id=TECH196717, this says:
The UDID is a tuple( 4 field) consisting of : VendorId , Product ID, Cabinet Serial number , Lun Serial Number
So it would seem the Cabinet Serial number is resolving to the hostname and the Lun Serial Number is resolving to the O/S device path.
Vbox seems to emulate all disks, local AND shared to be in a single enclosue within the host (i.e internal disks), so I guess this is why the issue is arising as Vbox is reporting a single shared disk is contained in both hosts (and sometimes reporting a different Lun Serial Number if the device path for the disk is not the same on each host, which occurs if you have a different number of disks on each system or the controllers are not discovered in the same order).
I had a look on VMWare workstation and this does the same - it seems to emulate all disks, local AND shared to be in a single enclosue within the host
Does anyone know how to work-a-round this?
Thanks
Mike