Pruning while other clients are backing up to the same storage

Support
#1

Hey all,

I’m planning a new duplicacy deployment and I’m a little confused about the behavior of prune with multiple clients. I’m planning to have ~5 clients backing up to the same storage on a NAS, but it’s not clear from forum posts or the docs on whether it can cause issues for a client to prune -all if it happens to occur when another client is backing up.

I can attempt to stagger them but obviously it’s impossible to guarantee that jobs won’t happen simultaneously on occasion.

If this could be a problem, how would you suggest I work around it safely?

Thanks!

#2

Duplicacy is fully concurrent, it is designed for this usecase, and will work just fine (as long as you don’t use -exclusive flag).

#3

Thanks! So just to confirm, it’s safe to prune while another client is backing up but unsafe for two clients to prune at the same time?

#4

Both are fine to do concurrently.

Have a look at this paper if you want details on how it works: Duplicacy paper accepted by IEEE Transactions on Cloud Computing

#5

If possible, I would avoid -exhaustive in concurrent situations as well, even non-exclusive. Exhaustive prune may fossilize chunks that were just uploaded (but were not made a part of a snapshot yet). In theory this shouldn’t be an issue as later operations should de-fossilize these chunks, but I am not sure how well this scenario has been tested considering this is a bit of an edge case.