[linux-lvm] how to copy a snapshot, or restore snapshot without deleting it
Matthew.Davis.2 at team.telstra.com
Thu Jan 17 01:12:36 UTC 2019
What do you mean "it's origin is already gone"?
It is a snapshot of centos/root, which still is there. (I have since modified centos/root)
So the origin is still there.
I think it's because I merged the copy of the snapshot. If I merge the original snapshot, the copy remains and it's origin changes.
That seems to work.
* make snapshot fresh1
* change contents of root
* copy fresh1 to fresh2
* merge fresh1
* root is now restored to how it was originally
* fresh 2 now has origin root
(Although I get a daunting error message every time I create a snapshot, and sometimes I get error messages on merge, but it works most of the time.)
From: Zdenek Kabelac <zkabelac at redhat.com>
Sent: Thursday, 17 January 2019 12:55:59 AM
To: Davis, Matthew; LVM general discussion and development
Subject: Re: how to copy a snapshot, or restore snapshot without deleting it
Dne 16. 01. 19 v 0:03 Davis, Matthew napsal(a):
> Hi Zdenek,
> Here's what I see with `sudo lvs -a`. (My snapshots are actually called `fresh` and `fresh2` not `mySnap`)
> LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
> fresh centos Vwi---tz-k <1.46t pool00
> fresh2 centos Vwi---tz-k <1.46t pool00 fresh
So these both LVs are snapshots (since they were created with s(k)ipped
activation - however 'fresh' LV cannot be merged anymore as it's origin is
But 'lvconvert --merge centos/fresh2' should work - yet you need to
manually drop 'k' flag (via lvchange).
So to have 'working' merge - you have to see something in the 'Origin' field.
If the Origin field is already 'empty' you can't be merging such LV even when
it was originally created as 'snapshot'.
Also note that thin snapshot merging is nothing else then a bit more 'smart'
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