[CentOS] High load averages copying USB

[Giovanni Tirloni]

On Thu, Apr 26, 2012 at 10:18 PM, Lists <lists at benjamindsmith.com> wrote:

> On 04/20/2012 05:24 AM, Giovanni Tirloni wrote:
> > On Apr 20, 2012 2:42 AM, "Lists"<lists at benjamindsmith.com>  wrote:
> >> Problem as follows:
> >>
> >> 1) Plug in an external USB drive.
> >>
> >> 2) Mount it anywhere. Doesn't matter how.
> >>
> >> 3) Copy a few GB of data to the drive from a non-USB disk.
> >>
> >> 4) Watch the load average "climb" to 5.x, sometimes 10.x or more. Why?
> >> This on an otherwise unloaded system. Doesn't matter how many cores, how
> >> much RAM, 32/64 bit, etc.
> >>
> >> Why should copying some files to a USB drive cause load averages to
> >> climb so high? (and network monitors to freak out?)
> > It's just a number. Is the system any slower?
> >
> > Linux adds I/O wait time to the load average calculation.
>
> Problem isn't so much actual "speed" but causing network monitors to
> freak out due to "high" load average
> when performing backups. I can make exceptions for servers doing
> backups, but then I don't get notifications when
> the load is legitimately high. I can make exceptions only during backup
> times, but that increases complexity.
>
> Seems silly that load average would climb to 2.x or more copying some
> files on an otherwise lightly loaded server.
>
>
You might be better off monitoring CPU usage instead of load average in
Linux.


-- 
Giovanni