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List:       linux-lvm
Subject:    Re: [linux-lvm] Doubts on Snapshots
From:       Larry Dickson <ldickson () cuttedge ! com>
Date:       2009-02-04 15:14:43
Message-ID: 1c748a490902040714l650f46a3wecc2a8d268456506 () mail ! gmail ! com
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This is a misunderstanding of what snapshot does. To minimize copying, it
makes a special volume containing the OLD versions of only those sectors
CHANGED since the snap was made. Thus, when mated with the original,
continually-being-updated volume, it can reconstruct its state at the time
of the snap. Without the original, it cannot do much.

I think what you want is mirroring or rsync.

Larry Dickson
Cutting Edge Networked Storage

On 2/4/09, Rahul Baheti <rahulbaheti86@gmail.com> wrote:
>
>
>
>
> I have connected a pen drive and make a logical volume from it. then i take
> a snapshot of this logical volume and the snapshot logical volume lies in
> hard disk. After that i plugged out the pen drive. Without pen drive being
> plugged into the system can i recover the data of pen drive using the
> snapshot volume.
>
>
> Waiting for reply
>
> Thanks and Regards
>
> Rahul Baheti
>
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>

[Attachment #5 (text/html)]

<div>This is a misunderstanding of what snapshot does. To minimize copying, it makes \
a special volume containing the OLD versions of only those sectors CHANGED since the \
snap was made. Thus, when mated with the original, continually-being-updated volume, \
it can reconstruct its state at the time of the snap. Without the original, it cannot \
do much.</div>

<div>&nbsp;</div>
<div>I think what you want is mirroring or rsync.</div>
<div>&nbsp;</div>
<div>Larry Dickson</div>
<div>Cutting Edge Networked Storage<br>&nbsp;</div>
<div><span class="gmail_quote">On 2/4/09, <b class="gmail_sendername">Rahul \
Baheti</b> &lt;<a href="mailto:rahulbaheti86@gmail.com">rahulbaheti86@gmail.com</a>&gt; \
wrote:</span> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px \
0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><br> <div class="gmail_quote"><br><br>I \
have connected a pen drive and make a logical volume from it. then i take a snapshot \
of this logical volume and the snapshot logical volume lies in hard disk. After that \
i plugged out the pen drive. Without pen drive being plugged into the system can i \
recover the data of pen drive using the snapshot volume. <br> <br><br>Waiting for \
reply<br><br>Thanks and Regards<br><font color="#888888"><br>Rahul \
Baheti<br><br></font></div><br><br>_______________________________________________<br>linux-lvm \
mailing list<br><a onclick="return top.js.OpenExtLink(window,event,this)" \
href="mailto:linux-lvm@redhat.com">linux-lvm@redhat.com</a><br> <a onclick="return \
top.js.OpenExtLink(window,event,this)" \
href="https://www.redhat.com/mailman/listinfo/linux-lvm" \
target="_blank">https://www.redhat.com/mailman/listinfo/linux-lvm</a><br>read the LVM \
HOW-TO at <a onclick="return top.js.OpenExtLink(window,event,this)" \
href="http://tldp.org/HOWTO/LVM-HOWTO/" \
target="_blank">http://tldp.org/HOWTO/LVM-HOWTO/</a><br> </blockquote></div><br>



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