I have some problems with copying LV volumes and determining correct size. For instance, if I want to copy an LV from one machine to another. I dd the LV to a file on the other machine, then dd the file to the new LV. That fails, because a few MB are missing.
source: LV Name /dev/VolGroup01/LogVol01 LV Size 4.62 GB
target: LV Name /dev/xenvm/lvmtest1 LV Size 4.62 GB
Both were created with lvcreate -L 4.62GB, but there's obviously a small rounding or whatever difference. The size of the physical extents seems to be different.
I can determine the size of the output file -rw-r--r-- 1 root root 4966055936 Apr 30 21:19 lvmtest1.img
That is 4849664K which is the smallest size unit that lvcreate accepts. lvcreate -L 4849664K --name lvmtest1 xenvm - and then it fits. But I hope there's a better way to determine the *exact* size?
Kai