Parallel copies : I don't get it

Discuss new features and functions
Posts: 5
Joined: 25 May 2020

zilog256

Hi there.

I've been a regular user of FFS, which makes my everyday life and my backups so much easier ; I registered/contributed a couple of times, and it's 100% worth it :)

That being said, I'm a bit at a loss when it comes to parallel copies.

=> WHAT IS MY SETUP:

Let's say I have 4 HDDs on my computer : A,B,C,D and an external enclosure with 4 HDD for mirror/backup, named E,F,G,H.

I have a batch job which makes the "obvious" copying : A to E, B to F, C to G, and D to H.

Until now I had a slow USB3 external enclosure : even with single drive copying, the performance was rather miserable (100 Mb/sec, but the drives can do better)

I got my hands on a much better enclosure with USB-C & all bells'n'whistles: I just tried benching them at the same time : they max out!

=> WHAT I WOULD LIKE TO DO:

I'd like to have the copying done IN THE SAME TIME, HDD to HDD, not one after another!

I understand the parallel copying allows fast drives such as SSDs to be read/written to/from multiple sources/dest but that is not what I need.

So OK, what I can do is 4 single JOBS (drive per drive) and launch them at the same time.

But...that can't be it, right?

Thanks!
User avatar
Posts: 3551
Joined: 11 Jun 2019

xCSxXenon

That is the only way. If all pairs are in a single config, it will do them consecutively. Youcan get around it by running a small batch file that runs the four syncs independently. The parallel copy settings doesn't open a separate thread for each pair, but opens them in a queue following the sync list. It is more more network locations that artificially limit a single connection speed.
Posts: 5
Joined: 25 May 2020

zilog256

Hey there, thanks for your answer.

Ultimately I understand that, if only because of the "unique" transfer windows.

I gave it a quick try :

1) created 4 ffs_batch files corresponding to the 4 pairs of source/dest copies

2) I had to do some googling to find how to run PARALLEL commands in cmd :
start "" C:\_FFS\BATCH1.ffs_batch
start "" C:\_FFS\BATCH2.ffs_batch
start "" C:\_FFS\BATCH3.ffs_batch
start "" C:\_FFS\BATCH4.ffs_batch
Seems fine, I'll test this !
User avatar
Posts: 3551
Joined: 11 Jun 2019

xCSxXenon

That's it! If you run into trouble, try expanding the commands to:
start "" "C:\Program Files\FreeFileSync\FreeFileSync.exe" "C:\_FFS\BATCH1.ffs_batch"
Having an absolute path can eliminate possible issues
Posts: 5
Joined: 25 May 2020

zilog256

For now it works fine as is, thanks for your help ! :)