[linux-lvm] Restoring method Snapshot to Orginal Volume

[linux-lvm] Restoring method Snapshot to Orginal Volume

[Antony MARTINEAU]

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Hello,
I am using LVM2 whith XEN
All of my DomU disks are one or more logical volume
For exemple /dev/vg0/lv1

For the moment when i want do a domU backup, i take a snapshot, do an 
image (dd gzip) of the snapshot, delete the snapshot and restor the dd 
image on the original logical volume.
so

Backuping
lvcreate -s -L500M -nlv1.snap /dev/vg0/lv1
dd if=/dev/vg0/lv1.snap bs=16M | gzip | dd of=/lv1.gz bs=16M
lvremove /dev/vg0/lv1.snap

Restoring
gzip -dc /lv1.gz | dd of=/dev/vg0/lv1

This method is very weight and not useful

ideally 
dd if=/dev/vg0/lv1.snap of=/dev/vg0/lv1 should be perfect but it is 
impossible because when restoring snapshot on the original volume, the 
snapshot continue to increase until to become fully and inactive

Is there a solution to deactive the cow (copy and write)for during the 
restoration about snapshot to original volume ?










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[linux-lvm] Restoring method Snapshot to Orginal Volume

[Antony MARTINEAU]

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Hello, 
I am using LVM2 whith XEN 
All of my DomU disks are one or more logical volume 
For exemple /dev/vg0/lv1 

For the moment when i want do a domU backup, i take a snapshot, do an 
image (dd gzip) of the snapshot, delete the snapshot and restor the dd 
image on the original logical volume. 
so 

Backuping 
lvcreate -s -L500M -nlv1.snap /dev/vg0/lv1 
dd if=/dev/vg0/lv1.snap bs=16M | gzip | dd of=/lv1.gz bs=16M 
lvremove /dev/vg0/lv1.snap 

Restoring 
gzip -dc /lv1.gz | dd of=/dev/vg0/lv1 

This method is very weight and not useful 

ideally 
dd if=/dev/vg0/lv1.snap of=/dev/vg0/lv1 should be perfect but it is 
impossible because when restoring snapshot on the original volume, the 
snapshot continue to increase until to become fully and inactive 

Is there a solution to deactive the cow (copy and write)for during the 
restoration about snapshot to original volume ? 




MARTINEAU
Antony 
Service informatique 
Assistant informatique 
LIPPI Management 
La Fouillouse
16440 Mouthiers sur Boheme 
Tel.: 05.45.67.34.35
Courriel: antony.martineau@lippi.fr
http://www.lippi.fr 








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savoir plus cliquer ici

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Re: [linux-lvm] Restoring method Snapshot to Orginal Volume

[Tomasz Chmielewski]

Antony MARTINEAU schrieb:

(...)

> ideally
> dd if=/dev/vg0/lv1.snap of=/dev/vg0/lv1 should be perfect but it is 
> impossible because when restoring snapshot on the original volume, the 
> snapshot continue to increase until to become fully and inactive

Increase your snapshot size then.


> Is there a solution to deactive the cow (copy and write)for during the 
> restoration about snapshot to original volume ?

See the "ANNOUNCE: an experimental implementation of snapshot merging" 
thread.


-- 
Tomasz Chmielewski
http://wpkg.org

Re: [linux-lvm] Restoring method Snapshot to Orginal Volume

[Tomasz Chmielewski]

Antony MARTINEAU schrieb:

(...)

> ideally
> dd if=/dev/vg0/lv1.snap of=/dev/vg0/lv1 should be perfect but it is 
> impossible because when restoring snapshot on the original volume, the 
> snapshot continue to increase until to become fully and inactive

Increase your snapshot size then.


> Is there a solution to deactive the cow (copy and write)for during the 
> restoration about snapshot to original volume ?

See the "ANNOUNCE: an experimental implementation of snapshot merging" 
thread.


-- 
Tomasz Chmielewski
http://wpkg.org