Adding space to Logical Volume Group by expanding the underlying physical disks?
Greetings! We run a TSM server on a virtual RHEL6 system hosted by z/VM. The TSM databases are stored on a logical volume group that's getting close to running out of space. An obvious solution would be to add more DASD to the LVG. But because we're also running low on device numbers I've been tasked with exploring the possibility of expanding the physical drives currently used by the LVG. I've been studying a message thread from June of last year titled "Extending a DASD partition" which seems to suggest that this approach is possible. The approach I'm thinking of is to * Allocate a single new drive much larger than the existing LVG physical drives. * Copy physical drive #1 to the new drive. * Redefine drive #1 to be larger * Copy physical drive #2 to the expanded drive #1 * Repeat with drives #3 through #n * Delete drive #n With this approach we only need to allocate one additional device number, and only for a limited period of time. Does this approach sound reasonable? There's one issue that I can think of, though: I'll be starting out with a set of devices allocated to the LVG: /dev/dasdc through /dev/dasdj. When I'm finished, I'll have dasdd through dasdk. It's not clear to me where the assignment of devices to the LVG is kept and whether it could easily be hand-edited. I'm open to any comments or suggestions you folks might have! Eric -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Adding space to Logical Volume Group by expanding the underlying physical disks?
Eric, I am a SuSe person, but I would consider using the pvmove command to copy physical volumes around. The lvm physical volumes would not have to be the same size. That is, you can copy directly from a smaller lvm physical volume to a larger lvm physical volume and would not have to expand it. (Eliminates step 3 from your process). Ron Foster Baldor Electric Company 5711 R S Boreham Jr Street Fort Smith, AR 72901 Phone:479-648-5865 Fax:479-646-5440 Email: ron.fos...@baldor.abb.com IM Address:rfos...@baldor.com www.baldor.com From: Linux on 390 Port [LINUX-390@VM.MARIST.EDU] on behalf of Eric Chevalier [et...@tulsagrammer.com] Sent: Friday, June 21, 2013 10:34 AM To: LINUX-390@VM.MARIST.EDU Subject: Adding space to Logical Volume Group by expanding the underlying physical disks? Greetings! We run a TSM server on a virtual RHEL6 system hosted by z/VM. The TSM databases are stored on a logical volume group that's getting close to running out of space. An obvious solution would be to add more DASD to the LVG. But because we're also running low on device numbers I've been tasked with exploring the possibility of expanding the physical drives currently used by the LVG. I've been studying a message thread from June of last year titled "Extending a DASD partition" which seems to suggest that this approach is possible. The approach I'm thinking of is to * Allocate a single new drive much larger than the existing LVG physical drives. * Copy physical drive #1 to the new drive. * Redefine drive #1 to be larger * Copy physical drive #2 to the expanded drive #1 * Repeat with drives #3 through #n * Delete drive #n With this approach we only need to allocate one additional device number, and only for a limited period of time. Does this approach sound reasonable? There's one issue that I can think of, though: I'll be starting out with a set of devices allocated to the LVG: /dev/dasdc through /dev/dasdj. When I'm finished, I'll have dasdd through dasdk. It's not clear to me where the assignment of devices to the LVG is kept and whether it could easily be hand-edited. I'm open to any comments or suggestions you folks might have! Eric -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Adding space to Logical Volume Group by expanding the underlying physical disks?
Ron, Thank you very much for that suggestion. It looks like it might be exactly what I want! I'm assuming I still need to "fdasd" to perform the intial format of the new drive, then just pvmove? If the answer is "yes", you've just made my day! Eric On 6/21/13 11:03 AM, Ron Foster wrote: Eric, I am a SuSe person, but I would consider using the pvmove command to copy physical volumes around. The lvm physical volumes would not have to be the same size. That is, you can copy directly from a smaller lvm physical volume to a larger lvm physical volume and would not have to expand it. (Eliminates step 3 from your process). Ron Foster -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Adding space to Logical Volume Group by expanding the underlying physical disks?
dasdfmt to format the dasd. fdasd to partition it pvmove to move the data. Yes it have done this and it has worked. One caveat, sometimes you cannot move the entire physical volume with one command. You have to move it a logical volume at a time. But we can cross that bridge when you get there. Ron Foster Baldor Electric Company 5711 R S Boreham Jr Street Fort Smith, AR 72901 Phone:479-648-5865 Fax:479-646-5440 Email: ron.fos...@baldor.abb.com IM Address:rfos...@baldor.com www.baldor.com From: Linux on 390 Port [LINUX-390@VM.MARIST.EDU] on behalf of Eric Chevalier [et...@tulsagrammer.com] Sent: Friday, June 21, 2013 11:19 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: Adding space to Logical Volume Group by expanding the underlying physical disks? Ron, Thank you very much for that suggestion. It looks like it might be exactly what I want! I'm assuming I still need to "fdasd" to perform the intial format of the new drive, then just pvmove? If the answer is "yes", you've just made my day! Eric On 6/21/13 11:03 AM, Ron Foster wrote: > Eric, > > I am a SuSe person, but I would consider using the pvmove command to copy > physical volumes around. The lvm physical volumes would not have to be the > same size. That is, you can copy directly from a smaller lvm physical volume > to a larger lvm physical volume and would not have to expand it. (Eliminates > step 3 from your process). > > Ron Foster -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Adding space to Logical Volume Group by expanding the underlying physical disks?
On 21 June 2013 17:34, Eric Chevalier wrote: > Greetings! > > We run a TSM server on a virtual RHEL6 system hosted by z/VM. The TSM > databases are stored on a logical volume group that's getting close to > running out of space. An obvious solution would be to add more DASD to > the LVG. But because we're also running low on device numbers I've been > tasked with exploring the possibility of expanding the physical drives > currently used by the LVG. I've been studying a message thread from June > of last year titled "Extending a DASD partition" which seems to suggest > that this approach is possible. The approach I'm thinking of is to > What do you mean with "running low on device numbers" ? You should at least be able to get 64 devices from the eckd driver (and I think he can pick another major number after that). You don't sound near to that yet. By far the easiest is to add a couple of physical volumes to the volume group and extend the logical volumes (if you have striped, you can still do that as long as you add the right number of PV's). Rob -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
