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amarnathreddy19
Contributor
Contributor

Virtual Machine Disk I/O high read and write

For the past few months, VM has very high disk read and writes. These I/Os are usually in the 20 MB read and 5 MB writes range. The pattern is constant: 2 minute lull followed by a 10 minute I/O burst, usually occurring between 4 AM until noon every day, weekend included. These "runs" are about 8 hours long, and sometimes they can occur between 8AM and 4PM.

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vmroyale
Immortal
Immortal

Hello.

What is the guest OS?

What role, or apps, does this server have (db, mail, f/p, etc)?

Has anything changed lately?

Can users schedule jobs?

Good Luck!

Brian Atkinson | vExpert | VMTN Moderator | Author of "VCP5-DCV VMware Certified Professional-Data Center Virtualization on vSphere 5.5 Study Guide: VCP-550" | @vmroyale | http://vmroyale.com
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AWo
Immortal
Immortal

Virus scan?

Backup?

Defragmentation?

Database scheduled jobs?


AWo

VCP 3 & 4

Author @ vmwire.net

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amarnathreddy19
Contributor
Contributor

OS= windows 2003 standard edition 32 bit

Yes 3 scheduled tasks were set to run.

How to overcome this porblem, appreciate your help

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AWo
Immortal
Immortal

You may want to answer vmroyale's questions and be some more detailed about the three jobs you run. We do not have enough information to help, yet. It can be all but not nothing....


AWo

VCP 3 & 4

Author @ vmwire.net

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amarnathreddy19
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1. abc batch file configured to scheduled tasks, runs at 3:30 am every day starting 4/4/2009 till

goes to 30-60 mins, if it runs beyond 72 mins task will be stopped (i belive that is why Disk very high disk read and

write)

2. xyz batch file configured to shceduled task, runs at 4:AM every day

starting 4/4/2009

3. 123 batch file, this will run at system

startup

and i do not see any other os issues

Thanks in advance

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AWo
Immortal
Immortal

Are you facing any problems? If abc is the job causing high I/O rates, do you consider that as O.K.?

In short words: do you need any further help?


AWo

VCP 3 & 4

Author @ vmwire.net

\[:o]===\[o:]

=Would you like to have this posting as a ringtone on your cell phone?=

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amarnathreddy19
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Are you facing any problems? If abc is the job causing high I/O rates,

do you consider that as O.K.?

if abc is running i dont want o see high I/O rates...is there any settings or tweaking for this.

Thanks in advance

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AWo
Immortal
Immortal

Again, we don't know what abc is doing. If it is a defragmentation for example or any other tasks which included read and writes to disks, a higher I/O is normal. Only you can tell...

But to give an general advice regarding I/O's you should take care that the VMFS parttion and the guest partitions are aligned:

http://www.vmware.com/pdf/Perf_Best_Practices_vSphere4.0.pdf

Search for "align" in this document.

This document explains the background: http://www.vmware.com/pdf/esx3_partition_align.pdf


AWo

VCP 3 & 4

Author @ vmwire.net

\[:o]===\[o:]

=Would you like to have this posting as a ringtone on your cell phone?=

=Send "Posting" to 911 for only $999999,99!=

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amarnathreddy19
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Contributor

I am sure that abc is not related to defragmentation, i belive this is something related to application

i've seen the tasks properties of abc it shows source and destination to copy some files.

and also i've observed that mem usuage is high at the time of running the abc task.

Thanks in advance

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AWo
Immortal
Immortal

i've seen the tasks properties of abc it shows source and destination to copy some files.

and also i've observed that mem usuage is high at the time of running the abc task.

So, increased I/O and higher memory usage sounds normal to me for a job which copies files.


AWo

VCP 3 & 4

Author @ vmwire.net

\[:o]===\[o:]

=Would you like to have this posting as a ringtone on your cell phone?=

=Send "Posting" to 911 for only $999999,99!=

vExpert 2009/10/11 [:o]===[o:] [: ]o=o[ :] = Save forests! rent firewood! =
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