xen-users
Re: [Xen-users] Xen with LVM
IDAGroup - R.W.Muller wrote:
Hi Errol
Errol Neal wrote:
Quoting "IDAGroup - R.W.Muller" <robin@xxxxxxxxxxx>:
Hello Errol, I tried that and get a little weird partition table:
sfdisk -l -uS /dev/vms/centos5_data
Disk /dev/vms/centos5_data: 0 cylinders, 0 heads, 0 sectors/track
Warning: The partition table looks like it was made
for C/H/S=*/255/63 (instead of 0/0/0).
For this listing I'll assume that geometry.
Units = sectors of 512 bytes, counting from 0
Device Boot Start End #sectors Id System
/dev/vms/centos5_data1 * 63 3068414 3068352 83 Linux
/dev/vms/centos5_data2 0 - 0 0 Empty
/dev/vms/centos5_data3 0 - 0 0 Empty
/dev/vms/centos5_data4 0 - 0 0 Empty
I wouldn't worry too much about that. sfdisk is probably just
confused. Since the file doesn't have a ioctl, that would be my guess
Ok I just ignore this partitions :)
Now I just have to find out, how I can get ride of the Empty partitions
and how to use snapshot for backup and I'm getting closer
to a usable result :)
lvcreate -L1G -n vmsnap /dev/vms/centos5_data
Then mount it as above. Keep in mind that for snapshots, all changes
to the live volume are written to the COW table on the snapshot
volume. Make sure you allocate enough space for this.
Ok, that means I need at least douple the hardware space then the size
of the LV, or I'm wrong with this?
....let's say my LV centos5 is 80GB in size, will I need a 160GB
harddrive in this blade server in order to get the snapshot and then
mount and rsync it to another harddrive? ...or what do you recomment
for backup purpose?
Thanks,
Robin
You don't need to allocate the double size of your original LV. As Erol
said, you have just to allocate enough space to contains all changes
made (i.e. writing) on the original partition during the snapshot life.
For example if a snapshot is created à 00:00 am and deleted at 03:00 am,
and there's no activity on the original LV, you don't need that much
space (just to contains syslog writing or things like this). But if
there's extensive usage of your original LV you need to allocate more.
Writing 600MB (downloading, whatever, ...) of data in your original LV
requires snapshots of at least 600MB.
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users
|