[linux-lvm] Newbie to snapshot
Heinz J . Mauelshagen
mauelshagen at sistina.com
Tue May 20 02:36:01 UTC 2003
On Sun, May 18, 2003 at 10:58:23PM +0800, armani wrote:
> Thanks for toby's explainations!
> ==
> Eventually I create a new snapshot of my LV partition.
> But I have another problem with the snapshot of LV.
> That is how much snapshot I could create for my LV partition ?
> As I know some commercial software could create 254 snapshots for one LV
> such as IBM.
>
> So I try to create another snapshot for LV by issuing the following command:
>
> This is my first snapshot for /dev/Vol1/LV1
>
> [root at met root]# lvcreate --size 100M -s -nsnapshot /dev/Vol1/LV1
> lvcreate -- WARNING: the snapshot will be automatically disabled once it
> gets full
> lvcreate -- INFO: using default snapshot chunk size of 64 KB for
> "/dev/Vol1/snapshot"
> lvcreate -- doing automatic backup of "Vol1"
> lvcreate -- logical volume "/dev/Vol1/snapshot" successfully created
>
> I tried to create another snapshot for /dev/Vol1/LV1
>
> [root at met root]# lvcreate --size 100M -s -nsnapshot1 /dev/Vol1/LV1
> lvcreate -- WARNING: the snapshot will be automatically disabled once it
> gets full
> lvcreate -- INFO: using default snapshot chunk size of 64 KB for
> "/dev/Vol1/snapshot1"
> lvcreate -- doing automatic backup of "Vol1"
> lvcreate -- logical volume "/dev/Vol1/snapshot1" successfully created
>
> And how can I estimate the sizes and counts for them ?
lvdisplay /dev/Vol1/snapsh*
> Is there any rules or principles to formalize the procedures ?
There's no tool in the LVM distro for that so far.
You can write a script (Shell, Perl, ...) around lvdisplay to
create alerts when a snapshot runs out of space or extend it automatically.
>
>
> > A snapshot will only capture what you have in the fs at the moment you
> -- snip --
> > -toby
>
> -- Armani Liao
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
--
Regards,
Heinz -- The LVM Guy --
*** Software bugs are stupid.
Nevertheless it needs not so stupid people to solve them ***
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Heinz Mauelshagen Sistina Software Inc.
Senior Consultant/Developer Am Sonnenhang 11
56242 Marienrachdorf
Germany
Mauelshagen at Sistina.com +49 2626 141200
FAX 924446
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