[Duplicity-talk] Restoring from Glacier Cold Storage

[ml]

Hello,

I am using duplicity 0.8.14 with the s3 backend to write to a Scaleway C14
Glacier storage (similar to Amazon S3 Glacier). Scaleway provides an
s3-compatible API and this is actually working very well.

I just noticed one glitch: When restoring from an archive in Glacier, it
seems to me that duplicity always processes one chunk after the other and
only unfreezes a chunk immediately before downloading it. What I mean is:
duplicity wants to download vol1.difftar.gpg (which is stored in Glacier)
and needs to unfreeze it. After unfreezing it downloads it and after that
processes vol2.difftar.gpg. And so on. As unfreezing can take multiple
hours that would mean the restore process will get extremely long with
bigger backups.

I would have expected that duplicity starts an unfreeze process for /all/
chunks it needs for the restore at the same time, so they will get
available for download at roughly the same time. Therefore the waiting cost
for unfreezing would have to be "paid" only once.

Is my observation correct or am I misinterpreting something?

Is this the expected behaviour? Actually the Glacier integration would be
quite useless in this case as a restore of a large backup would take
extraordinary amounts of time and to avoid that I would have to manually
unfreeze each file needed for the restore (which is also not easy, since I
don't know which files are really necessary for the restore.


Best regards
Marco