Re: [Duplicity-talk] File restore extremely slow

[Nate Eldredge]

On Thu, 27 Aug 2015, Grant wrote:

> Restoring an 85kb file like this took about 30 minutes:
>
> # duplicity --tempdir /root --use-agent --encrypt-key=........
> --sign-key=........ -t 7D --file-to-restore path/to/file.txt
> file:///backups /home/user/file.txt
>
> Would a 1MB file take 11 or so times longer?  Is there any way to speed that up?

In this case it's not related to the size of the data you're restoring, 
but rather the total size of the backup.  Duplicity has to decrypt and 
read through all volumes of the backup (starting with the most recent full 
backup) to find the data for file.txt and all relevant incremental updates 
to it.

So a 1MB or 10MB file would take about the same amount of time as your 
85kb file.  A 100MB file would take just slightly longer, because it may 
take a second or two to write the restored copy of the file itself.  And 
so on.  Restoring your entire backup set would take maybe an hour, or 
less, depending on the relative speed of your disk and CPU.  Try it and 
see!

Some ways you could speed it up, if you expect to frequently have to
restore individual files:

- Split your backup into multiple backup sets (using --include and
--exclude) so that each backup set has less data.

- If you have a relatively small amount of that data changes often, do
full backups more often, so that the total size of the incrementals since
the last full backup will be smaller.

--
Nate Eldredge
address@hidden