Kai Schaetzl
2008-Apr-30 20:43 UTC
[CentOS] determining correct size for LV copy operations
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 -- Kai Sch?tzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com
John R Pierce
2008-Apr-30 20:56 UTC
[CentOS] determining correct size for LV copy operations
Kai Schaetzl wrote:> 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. >I'd probably use dump ... | restore ... to copy it, assuming its an e2fs/e3fs on that logical volume. then the volume sizes are immaterial.