delete_later (backup purpose)

dormando dormando at
Fri Feb 1 19:02:07 UTC 2008

sanados wrote:
> as this mailinglist is alive i try to reask my question about delete_later.
> Sorry to post this question twice, but i think it went down the drain as 
> the second question in my email was answered already.
> I see mogilefs not only as a distributed filesystem, replication and 
> loadbalancing mechanism.
> I would also like to use mogilefs as backup.
> My guess is that many firms have to keep copies of files for some time 
> for legal issues.
> I don't to put an extra NAS online to just backup those files.
> The easiest way would be if we could just use delete_later and mogilefs 
> skips the deleting part and marks it as 'delete failed' and writes the 
> files to delte into the table "file_to_delete_later" with a given (or a 
> standard, or a config) value.
> I haven't found any option to make this work with the current release of 
> mogilefs.
> Have i just have to find those switch or does it not exist (yet) ?
> And is this feature on the todo-list?

I've been thinking about something similar... Along the lines of a 
delete_later protocol command which will shovel the fid directly into 
file_to_delete_later with a specified time into the future. This is only 
really useful as an undo though.

There're issues with keeping files in a deleted mode forever... One is 
that the file_to_delete_later table's probably not the best place to 
keep a copy of every deleted row ever.

Also, once it's in there it probably won't be considered by fsck or 
replication to update its replicated links. So as devices die by natural 
causes you'll be losing these files anyway.

It should be pretty easy to add a plugin hook to mogilefs to allow 
delete's to move files into either a separate mogilefs domain (hidden 
from the app! Still controlled by mogilefs!), or journaled to another 
storage device. I think that's more along the lines of what you'd want.


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