Get Local Disk WWID for Oracle ASM drive identification.

James9103

I am one of the VMWare ESXI users trying to migrate to another virtualization solution (XCP-ng Noob). One of my test cases is seeing if XCP-ng can support an Oracle Database running with GRID / Oracle Restart / ASM. When defining the ASM volumes I use the scsi_id command like /usr/lib/udev/scsi_id -g -u -d /dev/xvda2 to identify the WWID to add to the /etc/udev/rules.d/99-asm.rules file.

I dont see any options to define disks stored on the local disk store as SCSI nor does the /usr/lib/udev/scsi_id -g -u -d /dev/xvda2 return any values.

Has anyone found a solution to getting the WWID or any other method that works in the 99-asm.rules file using XCP-ng and local storage virtual disks?

I am using XCP-ng 8.2.1, XCP-ng Center 20.04.01, and Xen Orchestra Community Edition.

olivierlambert

Doc updated at https://docs.xcp-ng.org/vms/#disk-wwid

olivierlambert

Hi! And welcome

This thing rings a bell somehow, have we discussed that in the past @stormi or @yann ?

James9103

@olivierlambert, Thank you for the welcome. I am immediately impressed to see a response from a CEO and Co-Founder so quickly.

I do hope that XCP-ng has a solution for getting WWIDs. If it is not an option I would be curios if it is on your development radar and when you would estimate having this feature included in future releases. Thank you @stormi and @yann for any additional information you might have about compatibility with Oracle Database's with the Grid/ASM infrastructure.

James9103

@olivierlambert @stormi @yann just checking again to see if there is any information on current or future plans to provide a WWID for disks. Our University is exploring alternative options to VMWare for our virtual server infostructure and our Banner Student Information System which uses an Oracle database is one of our critical servers. I am the Database Administrator for that system so that is why I am doing testing now to see if XCP-ng is a viable option. So far, other than this WWID issue, XCP-ng seems to provide what we need. In VMWare they did not support WWIDs out of the box either. You had to do some extra configuration which is outlined in this article (https://access.redhat.com/solutions/93943) setting the following parameter: disk.EnableUUID = "TRUE". If you could get back with me I would appreciate it. Thanks.

olivierlambert

@dthenot can you take a look when you are around?

dthenot

@James9103 Hello, sorry for the delayed answer.

scsi_id would not work on /dev/xvdX devices since those are not SCSI based.
They are xen-blkfront devices using the blkif protocol.

It took me a bit of time to answer since I don't know about Oracle ASM.
From what I can read from ASM documentation, you only need stable identifier for disks.
Could you use some other kind of unique identifier?

Another thing is that there no current way to obtain a unique identifier for xen-blkfront devices, but that we could try to do something about.
I will be looking a bit more about on it.

James9103

@dthenot I assume that I should be able to use some other disk identification provided there is an executable that would generate a unique code for each disk partition given a /dev/xvdX parameter.
Based on the udev/rules.d/99-asm.rules PROGRAM syntax of PROGRAM=="/usr/lib/udev/scsi_id -g -u -d /dev/$parent".

I would be willing to try it if you could generate a unique identifier for the xen-blkfront devices.

Thanks for you assistance.

Timo

Hi,
the following blog post helped me to get Oracle Restart and ASM working:

"For persistent device naming, we can configure ASMLIB or set udev rules. We need to use a partition UUID (not a filesystem UUID) in udev rules"

https://alexzy.blogspot.com/2018/02/configuring-disk-devices-manually-for.html

James9103

@Timo Thank you so much for this information. I was able to use the the ID_PART_ENTRY_UUID or ID_PART_ENTRY_NAME variables in my /etc/udev/rules.d/99-asm.rules files and it seems to be working on my test database server.

@dthenot, @olivierlambert, @stormi, @yann. This issue has been resolved using the information @Timo provided. Thanks again for your assistance and VMWare alternative.

James...

olivierlambert

Thanks to you, both @Timo for a working solution and @James9103 for your feedback

Probably worth documenting that somewhere, any idea where @stormi or @dthenot ?

stormi

Likely in https://docs.xcp-ng.org/vms/

olivierlambert

Doc updated at https://docs.xcp-ng.org/vms/#disk-wwid

James9103

@olivierlambert Thank you. That should be helpful for future installs and for others with a similar situation.

olivierlambert

Indeed!