[CentOS] High load averages copying USB

Fri Apr 27 01:18:05 UTC 2012
Lists <lists at benjamindsmith.com>

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.