[ale] LVM snapshot backups

[DJ-Pfulio]

Ah ... must have confused LVM snapshots with some other sort, perhaps QCOW2
snapshots?
http://wiki.qemu.org/Documentation/CreateSnapshot  Yep. Sorry.  Different
use-case completely, hence the different results.



On 01/23/2016 02:09 PM, Jim Kinney wrote:
> The new data is written to the ORIGINAL lvm. At that point, the old data is
> written to the snapshot lvm.  The snapshot lvm is initially of zero real
> size, no disk space is used. Only when blocks need to be written to in the
> original lvm are blocks written to in the snapshot. Thus drive space used
> is double the size of the new data: one write to archive the old data in
> the snapshot and a second write to store the new data in the original lvm.
> Its a performance hit but an overall time saver. Think of the snapshot as
> nothing but hard links to physical extents until an extent changes.
> On Jan 23, 2016 12:42 PM, "DJ-Pfulio" <djpfulio at jdpfu.com> wrote:
> 
>> Concerning LVM backups.
>>
>> If all the change data is being written to the snapshot area, how does
>> that get
>> merged back into the main storage and main DB after we are done with
>> backups?
>>
>>
>>
>>
>> On 01/22/2016 02:40 PM, Jim Kinney wrote:
>>> Slide deck is live on ale.org in meeting announcement page.
>>> On Fri, 2016-01-22 at 10:54 -0500, DJ-Pfulio wrote:
>>>> Are there notes, the presentation, and/or video from last night?
>>>> Sounds like the presentation and some notes could really be helpful
>>>> based on the
>>>> comments.
>>>>
>>>> Sorry I missed it!
>> _________________________