LVM mirroring in SLES 10

[RonVH]

I am looking to convert an existing LV into a mirrored LV in order to migrate data from one disk to another. I have done this in HP-UX but never tried in Linux. I see there is no option to do lvextend -m1 but have found lvconvert -m1. When attempting that I get a strange error.

# lvconvert -m1 /dev/vgtest_x/lvol1 /dev/dm-21
Not enough PVs with free space available for parallel allocation.
Consider --alloc anywhere if desperate.

# pvs
PV VG Fmt Attr PSize PFree
/dev/cciss/c0d0p2 vg00 lvm2 a- 20.00G 6.40G
/dev/dm-13 vgDGC lvm2 a- 50.34G 50.34G
/dev/dm-16 vgDGC lvm2 a- 50.34G 50.34G
/dev/dm-17 vgDGC lvm2 a- 50.34G 50.34G
/dev/dm-18 vgDGC lvm2 a- 50.34G 50.34G
/dev/dm-19 lvm2 -- 8.43G 8.43G
/dev/dm-20 vgtest_x lvm2 a- 8.43G 8.43G
/dev/dm-21 vgtest_x lvm2 a- 8.43G 8.43G
/dev/dm-22 vgtest_x lvm2 a- 8.43G 2.43G


# SPident
CONCLUSION: System is up-to-date!
found SLE-10-x86_64-SP2