Why not just change references from /dev/disk/by-uuid to /dev/disk/by-path, such as in /etc/fstab and /boot/zipl/config ? Wouldn't that be easier in the long run?
Thanks, Sam -----Original Message----- From: Linux on 390 Port <[email protected]> On Behalf Of Aria Bamdad Sent: Friday, October 8, 2021 12:09 To: [email protected] Subject: Re: Warning if upgrading SLES12 to SLES15 SP3 Quoting Mark Post <[email protected]>: > On 10/8/21 2:10 PM, Alan Altmark wrote: >> The UUID only needs to be unique within a virtual server. I think >> the trick here is to use a cloning guest that links to the disk you >> want to clone so that the UUID is never duplicated within the owning >> guest. The cloning guest will have two copies, but it will never use >> those disks itself. >> >> This avoids having to assign new UUIDs. > > Perhaps, but it's still a good idea to make each clone unique. If you > ever need to link to another guest's disks, then duplicate UUIDs are > going to cause problems. And really, adding: > > tune2fs -U $(uuidgen) /dev/dasd?? > > to your cloning script is pretty straightforward. > I clone my disks using falashcopy so outside of linux. This would mean that after flashcopy, I would need to mount the disks on a utility linux server and change the UUID of each disk using tune2fs. That's fine and can be done. > I would also recommend not using chzdev when cloning disks and > manipulating them. Instead, use chccwdev, which doesn't cause any udev > rules to be written to deleted. The chzdev and lszdev commands are > really nice commands, but they are also more capable, and hence > complex, than what is needed during cloning. Use chzdev/lszdev for "normal" > system administration tasks where you actually want those udev rules > to be written/deleted. > > Yes, that would likely avoid all of the problems. However, in my case, I was in Yast and figured I will just activate a DASD using Yast menu. SLES12 Yast would call chccwdev but later versions and SLES15 now call chzdev. Had chzdev issued a message that the disk I am trying to activate has a UUID that conflicts with an existing disk that is currently activated, the entire problem would have been avoided. Instead it allows you to activate the disk. To make matters worse, while you are in Yast still, you no longer can deactivate the disk you just activated a second ago. Why? Because chzdev complains and yast will not continue. If we had the same complaint during activation of the disk, problem would have been avoided. Mark, your suggestion of using chccwdev is the right one. We can use chccwdev to online the device, mount it, fix the uuid and unmount/offline the device. Thanks, Aria > Mark Post > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO > LINUX-390 or visit > https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww2. > marist.edu%2Fhtbin%2Fwlvindex%3FLINUX-390&data=04%7C01%7CSam.Cohen > %40LRS.COM%7Cc99ab9efc4f144d5ebaa08d98a8f568c%7C62af9ccc42164ae2a1d306 > 614c59c315%7C1%7C0%7C637693170518903788%7CUnknown%7CTWFpbGZsb3d8eyJWIj > oiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&am > p;sdata=zc6faPNuqKiwmvWNxcGYwydyagoJWC4%2FXerg%2FEhP4FY%3D&reserve > d=0 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww2.marist.edu%2Fhtbin%2Fwlvindex%3FLINUX-390&data=04%7C01%7CSam.Cohen%40LRS.COM%7Cc99ab9efc4f144d5ebaa08d98a8f568c%7C62af9ccc42164ae2a1d306614c59c315%7C1%7C0%7C637693170518903788%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=zc6faPNuqKiwmvWNxcGYwydyagoJWC4%2FXerg%2FEhP4FY%3D&reserved=0 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
