Open Stack

On 3 February 2016 at 17:27, Sam Yaple <samuel at yaple.net> wrote:


>
> And here we get to the meat of the matter. Squashing backups is awful in
> object storage. It requires you to pull both backups, merge them, then
> reupload. This also has the downside of casting doubt on a backup since you
> are now modifying data after it has been backed up (though that doubt is
> lessened with proper checksuming/hashing which cinder does it looks like).
> This is the issue Ekko can solve (and has solved over the past 2 years).
> Ekko can do this "squashing" in a non-traditional way, without ever
> modifying content or merging anything. With deletions only. This means we
> do not have to pull two backups, merge, and reupload to delete a backup
> from the chain.
>

I'm sure we've lost most of the audience by this point, but I might as well
reply here as anywhere else...

In the cinder backup case, since the backup is chunked in object store, all
that is required is to reference count the chunks that are required for the
backups you want to keep, get rid of the rest, and re-upload the (very
small) json mapping file. You can either upload over the old json, or
create a new one. Either way, the bulk data does not need to be touched.



-- 
-- 
Duncan Thomas
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