Extremely slow local backup

MikeBrant     Jun 6 8:46AM 2018 GUI

Hi, I’m running an initial backup from my OS X computer to a local Synology and the transfer speed is incredibly slow (around 7mb/s). Is this a known/unknown issue or is this expected? Thanks a lot!


gchen    Jun 6 8:39PM 2018

Did you mean 7M bits/s? If so, it is a bit slow. You can try to increase the number of threads to 2 or 4, but please also make sure that the network or the NAS disk isn't the bottleneck.


MikeBrant    Jun 7 3:58AM 2018

Sorry I meant MB/s, I always get mixed up with the speeds :) I thought that for local it was better to use one thread?


gchen    Jun 7 1:13PM 2018

7MB/s isn't too bad. The one thread recommendation is for local disks only (not over a network). I don't know for sure if 2 threads would help, but you can try it with a single file like 1GB in size to see if there is any inprovement.


MikeBrant    Jun 7 5:23PM 2018

Thank you for your answer. How comes this isn’t too bad? Is it because of the way backups are split in thousands of files?


gchen    Jun 7 10:13PM 2018

What is the upload speed if you scp a large file to your NAS?


MikeBrant    Jun 9 12:07PM 2018

Ok, i can confirm that the nas is being the bottleneck here. My usual speed is 50MB/s but it looks like the Synology (DS716+) is unable to handle the big number of chunks optimally. Starting a backup on a local USB drive, I get 130MB/s at the beginning and then it gradually decrease to around 30-40MB/s which is acceptable.


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