Throttle The Disk I/O Rate: Limit disk I/O For rsync Tool

by on July 5, 2008 · 6 comments· LAST UPDATED September 2, 2012

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I run a backup script called /root/ which runs rsync command. However, rsync makes a lots of disk I/O and network I/O. I would like to reduce both disk and network I/O. My server has 10Mbps server connection with 160GB SATA hard disk. How do I reduce disk I/O so that the entire system does not die or become unresponsive?

This is a well known issue. There are two methods to control or throttle the disk and network I/O rate under UNIX / Linux while using the rsync command.

Method # 1: Limit I/O bandwidth

The --bwlimit option limit I/O bandwidth. You need to set bandwidth using KBytes per second. For example, limit I/O banwidth to 10000KB/s (9.7MB/s), enter:
# rsync --delete --numeric-ids --relative --delete-excluded --bwlimit=10000 /path/to/source /path/to/dest/

Method # 2: Take control of I/O bandwidth using ionice utility

The ionice command sets the io scheduling class and priority for a program or script. You can totally control disk i/o. See the following article for detailed examples:

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{ 6 comments… read them below or add one }

1 anonymous December 8, 2011 at 11:00 am



2 anonymous February 7, 2012 at 2:05 am

Check your grammar…. ionice command provide more control as compare to nice command.

should read:

The ‘ionice’ command provide more control as compare to the ‘nice’ command



3 anon March 24, 2013 at 8:55 am

redking… it’s as “compared to” not “as compare” to… check your grammar too if you wanna complain :)


4 asdf@asdf.tld July 25, 2013 at 3:33 pm

@anon, if you’re going to use quotes to illustrate the difference between original and corrective syntax, then you should use the quotes around the same group of words. Let me fix your poor correction to redking.

Should be “as compared to”, not “as compare to”

But then again, redking also missed pluralizing of provides.

Here is the final corrected sentence that both of you screwed up:

The ionice command provides more control as compared to the nice command.

You are welcome.


5 Michael Mounteney August 30, 2012 at 12:52 am

Hilarious ! English as she is spoke.


6 Balu November 19, 2012 at 1:40 pm

Thank you
server load due to rsync was driving me mad


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