On Tue, 07 Oct 2014, lee wrote: > Don Armstrong <d...@debian.org> writes: > > Doesn't matter. It just has to be a block device that you can add as > > a physical volume to the volume group. > > Isn't a logical volume of a volume group "just" a block device? The > VMs have their LVs as block devices just fine.
Sure. > > This is actually one of the many reasons why lvm is awesome. You can > > migrate whole servers from one set of drives to another with no > > downtime by using vgextend/pvmove/vgreduce. > > Provided that you have free space on your disks? You're swapping drives, so presumably one whole set of drives is empty. > Besides the swap partition, the only block device I have available is > a LVM logical volume which belongs to a different VG than the VG I > want to backup LVs of. > > The logical path would be to add the free LV from the other VG to the > VG that has LVs which I want to make snapshots of in order to back > them up because that's the only available block device. On Tue, 07 Oct 2014, lee wrote: > Can I merge multiple volume groups into one? Yes, using vgmerge, assuming one of the VG is inactivated. > I don't want to move LVs from one device to another. Is it possible to > reduce a VG by some amount which is in between the beginning and the > end of the VG (i. e. by the space which is now assigned to a LV)? > Isn't there a command like 'lvcopy' or 'lvbackup' or 'vgcopy' or > 'vgbackup'? It's called dd. > The VG is like this: [...] Lets back up here. What is the output of sudo pvs; sudo lvs; sudo vgs; ? Do I understand you correctly that you want to snapshot a logical volume, but currently don't have the space on the volume group that your logical volume is on? > It's very well possible that this VG doesn't reside on a partition but > on the device itself. How would I convert that into two partitions > without losing data? Volume groups don't reside on partitions or devices. They encompass physical volumes which do. You can't change the underlying partitioning scheme under a physical volume which is in use, but if you have enough space, you can migrate things out to make a phsyical volume unused. > That should be easily possible because the LVs can reside where they > are, and their container is the only thing that changes. Once they are > merged, I should be able to move any LV to any device which is part of > the VG. > > I wouldn't need to move any of the VGs because the VG resulting from the > merge would have free space so that I could finally make snapshots. > When I'm done with the snapshots, I could split the VG again. > > Is that possible? > > > -- > Hallowed are the Debians! > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: https://lists.debian.org/87vbnwg2w1....@yun.yagibdah.de > -- Don Armstrong http://www.donarmstrong.com This message brought to you by weapons of mass destruction related program activities, and the letter G. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20141007004855.ge14...@rzlab.ucr.edu
