Really bad disk performance

[ans2000]

Hi everyone. I'm new to VMWare, I'm having a really serious case of very poor disk performance and It's getting hard to me to troubleshoot it.

First of all I would like to post some information that may be useful to you.

I'm running VMware ESXi, 4.1.0, 260247. The Server is an HP ProLiant ML 150 G6 - Intel(R) Xeon(R) CPU E5504 @ 2.00GHz - 8GB RAM

I have only 1 VM, Windows SBS 2003 SP2 32bits. Inside the VM we run a custom software with SQL 2005 database. 

Everything worked properly. About 1 month ago I started noticing that our software started to work very slowly at certain hours of the day (One time during the morning and one more in the afternoon).

From vSphere client I could see that the storage system was performing poorly.

Here are some screen shots of the performance charts:

During During peak usage it's impossible to run our software, it gets really slow. The server never hangs, after a while (First it was 10-15 min, now up to1 hour) performance returns back to normal.

I checked for any process that may be causing de disk to perform slow (Antivirus software, backup software, etc.) and nothing is going on during that time.

I will be very grateful of any help you can give me.

If you need additional information please ask.

Kind regards

Andrés

[RvdNieuwendijk]

Hi Andrés,

Welcome to the VMware VMTN Communities.

I moved your question from Community Website Help to VMware ESXi™ 4.

[jdptechnc]

What are you using for storage?  Locally attached disk?  SAN?  NAS?

[ans2000]

Hi, I'm using local attached SCSI Disks 500GB

[a_p_]

Do you use a RAID controller with a battery/flash backed cache module? Ig so, check the battery to see whether this causes the issue. Without a fully charged battery the controller will operate in write-trough mode, which can really slow down disk performance.

André

[maishsk]

Welcome to the forums.

Did you say that it happens at certain times in the day?

Do you have another process running at the same time that requires a high amount of disk I/O?

[ans2000]

I will check this and get back to you.

Thanks,

Andrés

[Josh26]

As soon as you used the words "HP Server" and "Disk Performance", this thread was likely about a lack of RAID cache and battery backup