questions about LVM on RAID1 array
I've been setting up LVM on top of a RAID1 array.
So I mkraid to create /dev/md0, and then I pvcreate, vgcreate and
lvcreate using /dev/md0 as the physical device to stack on top of.
Having done all that, I then create an ext2 fs on the lv I've created.
All seems to work fine ... however ... pvdisplay shows me something I
really didn't expect ...
--- Physical volume ---
PV Name /dev/hdd
VG Name backup_volume_group
PV Size 186.30 GB / not usable 0
PE Size (KByte) 4096
Total PE 47694
Free PE 78
Allocated PE 47616
It shows me that the physical volume undelying my lv is /dev/hdd (one of
the two disks that form /dev/md0). Now the question becomes, is it just
a strange accident that it knows this, or is it simply drilling through
the raid and seeing the disks instead of the RAID1 device /dev/md0 ?
Slightly more concerning to me, is that when I cat'd /proc/mdstat before
I created the pv,vg and lv I saw the RAID device and the disks it was
using all shown correctly, however after I stacked on LVM I see this :
Personalities : [raid1] [multipath]
unused devices: <none>
Which worries me that the RAID is getting knocked off by LVM.
What I'm trying to achieve is an LVM underpinned by a RAID1 array. The
reason I need to stack LVM on top is because I will need to extend the
amount of space I have quite soon, and LVM is the easiest way to do
Any help is greatly appreciated,