I am planning to increase the disk space on my desktop system. It is running CentOS 5.9 w/XEN. I have two 160Gig 2.5" laptop (2.5") SATA drives in two slots of a 4-slot hot swap bay configured like this:
Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System /dev/sda1 * 1 125 1004031 fd Linux raid autodetect /dev/sda2 126 19457 155284290 fd Linux raid autodetect
Disk /dev/sdb: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System /dev/sdb1 * 1 125 1004031 fd Linux raid autodetect /dev/sdb2 126 19457 155284290 fd Linux raid autodetect
sauron.deepsoft.com% cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[1] sda1[0] 1003904 blocks [2/2] [UU]
md1 : active raid1 sdb2[1] sda2[0] 155284224 blocks [2/2] [UU]
unused devices: <none>
That is I have two RAID1 arrays: a small (1Gig) one mounted as /boot and a larger 148Gig one that is a LVM Volume Group (which contains a pile of file systems, some for DOM0 and some that are for other VMs). What I plan on doing is getting a pair of 320Gig 2.5" (laptop) SATA disks and fail over the existing disks to this new pair. I believe I can then 'grow' the second RAID array to be like ~300Gig. My question is: what happens to the LVM Volume Group? Will it grow when the RAID array grows? Or should I leave /dev/md1 its current size and create a new RAID array and add this as a second PV and grow the Volume Group that way? The documentation is not clear as to what happens -- the VG is marked 'resisable'.
sauron.deepsoft.com% sudo pvdisplay --- Physical volume --- PV Name /dev/md1 VG Name sauron PV Size 148.09 GB / not usable 768.00 KB Allocatable yes PE Size (KByte) 4096 Total PE 37911 Free PE 204 Allocated PE 37707 PV UUID ttB15B-3eWx-4ioj-TUvm-lAPM-z9rD-Prumee
sauron.deepsoft.com% sudo vgdisplay --- Volume group --- VG Name sauron System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 65 VG Access read/write VG Status resizable MAX LV 0 Cur LV 17 Open LV 12 Max PV 0 Cur PV 1 Act PV 1 VG Size 148.09 GB PE Size 4.00 MB Total PE 37911 Alloc PE / Size 37707 / 147.29 GB Free PE / Size 204 / 816.00 MB VG UUID qG8gCf-3vou-7dp2-Ar0B-p8jz-eXZF-3vOONr