High load during restore

[Ehsan]

I restored a backup which it's size was 4G,
During the restore , server's load reached 200.
Why the load goes such high during the restore?
What should I do to avoid it?

Any help would be much appreciated.

 

[zEitEr]

Hello,

Is it a VPS? I guess your disk subsystem is very busy there, and that makes slow all other processes... What does top show in the moment of restoring and before it?

 

[Ehsan]

No, It's dedicated with 8G Memory and 4 core cpu, I restored the file again to see what the top is showing,
The system is not busy before and after the restore and average load is about 0.5 ,
This time server's load reached to 370!
The top command shows "gzip -d" as most active process during the high load period.
Doesn't DA support cpuwatch as cPanel does?

 

[zEitEr]

If you want to get help on these forums, you'd better follow the recommendations, and give the output of the top. As without that with the same certainty of a success you can Google. The first 5 lines of top might help us to help you.

 

[Ehsan]

Here is the screenshot from top, atop and htop during the high load:

http://axgig.com/images/56037659577353485506.png
http://axgig.com/images/09288932842246419258.png

Regards

 

[zEitEr]

You've got 85% wa (wa = Waiting for I/O), your HDD is too busy, and that makes slow all the other processes. You might need to check your HDD(s) with smartmontools, and/or replace them.

 

[tincboy]

I've the same issue but during the backup,
I got many clients with more than 25 GB of files,
Doesn't DirectAdmin support something like cpuwatch of cPanel?

 

[zEitEr]

By default no, it does not support anything like cpuwatch. Though all tasks are being done with nice. So you might want to suggest it as feature.

Here I found a script, which can be modified a little to consider current LA and "pause tar`ing"

#!/bin/bash

# Usage:
# slowcmd.sh tar cf ~/backup.tar /usr/src/linux-2.6.25

"$@" &
PID=$!
echo "PID is $PID"
TOGGLE='Resume'
RUN_SECONDS=2
PAUSE_SECONDS=10

function procnumber () {
    echo `ps ax | awk -v var=$1 '{if($1==var){printf("%d", $1)}}'`
}

while [ "$PID" != "" ]; do
    if [ "$TOGGLE" = "Pause" ]; then
	echo "Stopping PID $PID"
	kill -s STOP $PID
	sleep "$PAUSE_SECONDS"
	TOGGLE='Resume'
    else
	echo "Resuming PID $PID"
	kill -s CONT $PID
	sleep "$RUN_SECONDS"
	PID=$(procnumber $PID)
	TOGGLE='Pause'
    fi
done

Anyway on this bases one can try to write a wrapper to tar binary, and use it on directadmin powered server