Backblaze B2 slow upload


Are there any details on the BB issue?

I notice that while Duplicati is really slow (70-80KB/s during file uploads so 50MB chunk files take about 10 minutes each to upload) adding a file manually through the BB web interface is quick, and uploads through other apps (I tested restic) don’t seem to be slowed down so much.

Maybe it’s something to do with the particular calls used by Duplicati being used to put files?


B2 upload speed suddenly plummeting has Backblaze seemingly fixing a network setting at their end, and increasing a Duplicati user’s upload speed by 10 times. They also say people can ask Backblaze support.

While testing on my own slow system yesterday, I raised its upload speed 20 times by reconnecting WiFi, which cleaned up its packet-level behavior quite a bit, and had it uploading at nearly my lines’s upload rate.

Below are before and after graphs, per my earlier comments about using Task Manager to see throughput.


You can see a slow and very uneven upload followed by a download spike which is the verification sample. After disconnecting and reconnecting my PC WiFi connection, the graph looks much faster and smoother:



That reddit thread was actually mine, lol. I was just about to come back in here and report that the issue seems to have been the pipe at Backblaze and appears (from my end) to have just cleared up by itself.


Yes I have also noticed a marked improvement in the past day or so.


B2 uploads working as they should! I put all backup traffic in a lower priority QoS class so that it can consume all my unused upload bandwidth, but not interfere with my regular upload traffic. Backup traffic is shown as green in this chart:

Before Backblaze fixed the issue, I was not maxing out my upstream bandwidth (which is about 20M).


I wish it would max out mine (or closer at least) - i’m still averaging 10 to 15 megabits and my connection is supposed to support 50 up.


Just a quick update to say that this morning yet again (much like last week at around the same time), my speeds suddenly plummeted by a factor of ~20. A 500mb dblock is now taking from a half hour to 80 minutes to upload.

Interestingly now when I try uploading a file directly to B2 via the web GUI, it goes at basically full speed. All while my Duplicati upload is struggling along at maybe 100KB/s.


Another small update - Backblaze support walked me through installing the backblaze CLI tool and asked me to do a CLI file upload. When I did, it ran at approaching 50 megabits - i tested using a copy of one of the duplicati chunks currently in my queue (roughly 500MB), and a file that duplicati is currently taking between a half hour and an hour to upload, took about 1 minute via the CLI. That’s discouraging.