Ubuntu 21.04. FFS very slow to mirror

Posts: 13 · m3110w 26 Jul 2021, 07:16

I'm trying to mirror 1.1 TB of data to an external 2TB USB 3.0 spinning hard drive. Very slow. I've set the value of 6 for parallel operations. The file transfer speed goes to about 200kB/s. VERY slow. How to fix this? How to optimize the number of parallel operations? I read the instructions here https://freefilesync.org/manual.php?topic=performance but when I do a comparison, the parallel copy values don't change and remain 1 and 1. How to optimize the parallel copy values?

What is making FFS so very slow? Is there a bug in Linux?

Have other people had problems with slow transfers in Linux? How did you fix it?

Posts: 4056 · xCSxXenon 26 Jul 2021, 14:36

Parallel operations will not help here. That will only help on artificially bandwidth limited connections, usually to network locations. Transfer speeds largely depend on number of files, how many there are, and storage devices. How many files make up this 1.1TB?

Posts: 13 · m3110w 26 Jul 2021, 15:17

Thanks for the info. Helps me understand the larger context. The 1.1TB consists of about 260,000 files. Many small files and some big video files.

Question: Say I purchase a small ethernet hub or switch and connect my laptop to it with an ethernet cable. The hub or switch has a USB 3.0 port in addition to ethernet ports. Then I connect my external hard drive to the hub or switch. Then I run the FFS sync job to the external drive. Would this setup be faster than directly connecting the external drive to the laptop USB port?

My guess is it will not be faster. But I want to check and make sure. I'm a tech newbie.

Posts: 4056 · xCSxXenon 26 Jul 2021, 15:39

In theory, the direct connection is always fastest.

Posts: 13 · m3110w 26 Jul 2021, 15:48

Ok,thanks. I wonder if they make external hard drives with an ethernet port in addition to a USB port? :-)

Posts: 4056 · xCSxXenon 26 Jul 2021, 15:49

Well I would wager your ethernet port is only 1Gb and is slower than the 5Gb that USB 3.0, now referred to as USB 3.2 Gen1, has. You may want to look into external SSDs instead, but be prepared for the monetary hit

Posts: 13 · m3110w 26 Jul 2021, 16:01

Interesting. I always assumed USB was slower than ethernet. Good to know the real story.

I have a 2TB nvme SSD that I use as an external drive. It's a clone of my main drive using Clonezilla. Only takes 30 minutes for the clone. Nice. Very fast.

If I get another stimulus check I'll get another one. :-)