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Cannot work as long as rsnapshot is working


#1

Since some time it occures everytime when rsnapshot is doing a backup for me, that it is almost impossible to work with the machine. The mouse and keyboard is responding very, very slow.
After the backup is finished I can work as before.
I didn’t change anything in the configuration of rsnapshot an the backup-medium is the same as before.

What to do to change this behaviour?

Thx!

Dieter


#2

Seems like the I/O is overun by your backup application which means the I/O scheduler cannot keep up and your system slows down.
There is no simple solution for this. There are some kernel options you could try like switching to the Bfq I/O scheduler. Though that is something I don’t feel comfortable posting here as it is very advanced and might not really fix the issue.


#3

thank you for your quick reply. But what does does the reply mean for me? Go shopping during the backup? :slight_smile:
Is it possible that to change the kernel itself might fix the problem? I’m using
uname -r
5.4.0-4-amd64

Ciao!

Dieter


#4

I don’t think the kernel change would change anything.
Installing iotop to check what happens when the cursor is not moving can help to see which process is eating all the I/O and try to limit rsnapshot maybe can help.
Otherwise you need faster media.


#5

ok, thanks.
I don’t know how to write the output of iotop in a file so I can give you here only some facts of what I have seen:

first line: Kworker with IO> 97% and prio be/4

followed by

rsync IO> between 40 - 80 % and diskread ~30M/s / ~30M/s diskwrite and prio be/4

Does this infos say something?

Dieter


#6

Any Ideas?

Ciao!

Dieter


#7

So that means rsync is really eating your I/O and apparently you have your external SSD connected to a slow connection (USB 2 maybe) as it only has 30M/s
Correct me if I am wrong.

This seems to be the bottleneck and the only thing I can tell you is really to let it run in the foreground in times you don’t need the computer.