[dm-devel] Limit on device bandwidth possible?

[Hauke Laging]

Hello,

I have not found anything about this on the web and in Usenet so I ask 
here:

Is there any way to limit the speed of a block device in software? I 
imagine this would be pretty cool for backups on a stand-alone 
workstation. Today the many disk accesses during the backups slow down my 
system too much. I have been told that the kernel cannot reduce the "I/O 
priority" of a task to handle this effect.

I think it would be a nice solution if an LVM snapshot volume was created 
with an option like "limit throughput to n MB/s (or n% of maximum)". There 
is something similar for network interfaces. It cannot be so difficult. 
Especially when using snapshot volumes you don't have to care from a data 
consistency perspective about the backup taking much longer.


Best regards,

Hauke