I want to try using LVM snapshots for backups. I'm working on an older CentOS 5 box, but I'm not sure if I can do it. From what I read, it seems like I need extra space on the physical disk in which to create a new volume. Is that the case? To me, from looking at the LVM command output, it looks like everything is full... It isn't, there is 13 GB free on the root filesystem, but I don't think that matters. This is my current state:
[root@server ~]# pvdisplay /dev/cdrom: open failed: No medium found --- Physical volume --- PV Name /dev/hda2 VG Name VolGroup00 PV Size 19.89 GB / not usable 19.49 MB Allocatable yes (but full) PE Size (KByte) 32768 Total PE 636 Free PE 0 Allocated PE 636 PV UUID O6N2b1-RxMe-gnEz-5Nkr-A7pA-AzLe-n2Qwy0 [root@server ~]# lvdisplay /dev/cdrom: open failed: No medium found --- Logical volume --- LV Name /dev/VolGroup00/LogVol00 VG Name VolGroup00 LV UUID PxmE7L-5B6b-Bvnp-zuca-SaiG-b20A-dDM4qq LV Write Access read/write LV Status available # open 1 LV Size 17.91 GB Current LE 573 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Name /dev/VolGroup00/LogVol01 VG Name VolGroup00 LV UUID uGP3Jz-pPJW-KLet-YZHC-5Uzn-8jT3-4GHPX7 LV Write Access read/write LV Status available # open 1 LV Size 1.97 GB Current LE 63 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 [root@server ~]# vgdisplay /dev/cdrom: open failed: No medium found --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 19.88 GB PE Size 32.00 MB Total PE 636 Alloc PE / Size 636 / 19.88 GB Free PE / Size 0 / 0 VG UUID vSc34e-sbP3-lwaj-PF9p-921E-3oP8-vkwJIz
Maybe I can shrink my / volume, then create a new one, then snapshot onto the new one? Is that the only way (without messing with hardware)?