[Dirvish] Updating/overwriting existing images

[Jason Boxman]

On Monday 07 August 2006 21:09, dirvish at GMxTechnologies.com wrote:
<snip>
> Design.  For most customers, there should only be 1 image per day,
> however, if the push to the staging area fails part way through and has
> to re-try/continue, or gets a manual update during the day, we need to
> update the daily snapshot (image).  Hence the desire to update an image,
> not create another one.

Fair enough.

<snip>
> That would make the logic behind the restoration web interface *really*
> ugly.  Most customers are expecting to see a backup view with the
> granularity of 1 day, not random dates and times.  Other customers have
> other levels of granularity, but none of them expect such randomness.
> This is why I have set the default image format in the default.conf for
> each customer. It makes implementation life much easier.

You can set it globally if it's always the same format, then override in 
specific vaults if you were to backup more often than daily.  The same 
applies to any configuration option you can specify in master.conf very 
nearly.

<snip>
> True, I could check for the existence of an image, but that would
> require my parsing the config file myself to determine the date format,
> and if an image *does* exist, that still doesn't help me unless I am
> deleting and replacing, vs any sort of updating or refreshing of the
> existing image.  It just seems to me that dirvish should help
> accommodate either updating an existing image, or rolling an existing
> into a new image with the same name or something.  Much like doing an
> update on a ZIP file just adds in the updates in place.

No, I don't believe it should.

Snapshots are point-in-time.  That it cannot be later updated should be 
considered a feature.  By definition it isn't a backup if it's subject to 
change at anytime.

-- 

Jason Boxman
http://edseek.com/ - Linux and FOSS stuff