On Wed, Oct 15, 2008 at 09:52:03AM -0700, Craig White wrote:
I have done the pgcreate and tested lvcreate but wonder about 'setphysicalextentsize' because in the man page, it states, "The default of 4 MB leads to a maximum logical volume size of around 256GB" which makes me think that if I want one volume when this is all done, I have to increase that value.
The man page for "vgcreate" says "there is a limit of 65534 extents in each logical volume" but only for *lvm1* format. lvm2 format doesn't have such restrictions.
I used default values for my 4Tbyte array (5*1Tbyte disk in a md raid5) under CentOS 4.
% fdisk -l /dev/md3
Disk /dev/md3: 4000.8 GB, 4000808697856 bytes 2 heads, 4 sectors/track, 976759936 cylinders Units = cylinders of 8 * 512 = 4096 bytes
% pvdisplay /dev/md3 --- Physical volume --- PV Name /dev/md3 VG Name Raid5 PV Size 3.64 TB / not usable 320.00 KB Allocatable yes (but full) PE Size (KByte) 4096 Total PE 953867 Free PE 0 Allocated PE 953867 PV UUID NngvXK-4tqJ-xNtG-UnDL-Rin0-RHIl-xZ2wzI
% vgdisplay Raid5 --- Volume group --- VG Name Raid5 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 1 Act PV 1 VG Size 3.64 TB PE Size 4.00 MB Total PE 953867 Alloc PE / Size 953867 / 3.64 TB Free PE / Size 0 / 0 VG UUID mKSI0h-26i7-5LK5-vwpX-GY3a-Bjiv-xX4q8n
% lvdisplay Raid5/Media --- Logical volume --- LV Name /dev/Raid5/Media VG Name Raid5 LV UUID c8x4Ip-R1wq-n9An-NM6B-IuBs-U61L-kfVgAU LV Write Access read/write LV Status available # open 1 LV Size 3.64 TB Current LE 953867 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:5
Does this make sense?
Try using "pvcreate", "vgcreate" and "lvcreate" with no special options and see what happens. It worked for me!
The default in CentOS should be lvm2; you can see that's what was created on mine by the "Format" line in the vgdisplay output.
Format lvm2