Comments for VMtoday

Comment on Balloon Driver Problems with SQL by Michael Maher

Michael Maher — Thu, 26 Jan 2012 11:02:03 +0000

Really interesting real world story. Thanks for sharing it.

Comment on Storage Basics – Part VII: Storage Alignment by Superkikim

Superkikim — Thu, 19 Jan 2012 15:40:28 +0000

Thank you for this article, and the references it contains. It’s useful.

It seems that the root cause of misalignement is a forgotten myth. I can’t find any references about it. Plenty of poeple are explaining why we have to align, but nobody talks about why the hell it works that way.

If I undertsand the story correctly, disk manufacturers reserve sector 0 to 63, and file system editors reserve sectors 1 to 64, generating the misalignement issue.

Also, I cannot find information about using extended partition. I was told a long time ago that if you make a single extended partition on a drive containing logical drives, you may not need to align. But I can’t get why as the MBR is present anyway.

Comment on High CPU Ready, Poor Performance by Onder

Onder — Thu, 19 Jan 2012 09:47:11 +0000

Hey,

you forgot 1 thing. The scheduler of ESX 4.0 does not work so effectively with large cu vCPU VMs as it is not putting the vCPUs on the same NUMA node. The vCPUs are spread out equally between pCPUs. So the high values of ready time are cause as well by waiting of for example vCPU#4 to get memory pages from vCPU#1 which is running on completely different pCPU.

NUMA node architecture optimization is fixed on scheduler of ESX 4.1.

Comment on IBM DS3300 iSCSI Write Performance Solved by Mike

Mike — Fri, 13 Jan 2012 04:20:33 +0000

Hi Josh, thanks for a great article. Do you happen to have the url where you downloaded the DS Command Line Interface? Is it a separate download or packaged with something else? I can’t seem to find it anywhere.

Comment on IBM DS3300 iSCSI Write Performance Solved by Mike

Mike — Fri, 13 Jan 2012 00:53:58 +0000

Thanks much for this article Josh. It’s been a big help in monitoring and performance tuning our ds3300. I’m having a hard time finding the command line interface. Do you remember, was it a separate download, or packaged with something else? Do you happen to have the url for the download?

Comment on Obtaining VMware Guest Disk Free Space for NFS Sizing by Richard

Richard — Wed, 04 Jan 2012 17:02:33 +0000

Is there a change that needs to be made to the function used for binding Excel to support 2010?
# Function used for binding to Excel
function Invoke([object]$m, [string]$method, $parameters)
{ $m.PSBase.GetType().InvokeMember($method, [Reflection.BindingFlags]::InvokeMethod, $null, $m, $parameters, [System.Globalization.CultureInfo]“en-US”) }

Comment on VMFS Volumes Missing!?!?! by Tárcio

Tárcio — Thu, 01 Dec 2011 18:19:21 +0000

Thanks for this help!

Comment on Storage Basics – Part V: Controllers, Cache and Coalescing by Karthik chowdary N

Karthik chowdary N — Wed, 16 Nov 2011 09:52:08 +0000

Good Explaination..Thanks!!

Comment on IBM DS3300 iSCSI Write Performance Solved by Joshua Townsend

Joshua Townsend — Mon, 14 Nov 2011 20:09:53 +0000

There are too many variables to give a fixed answer. It really depends on your workload (read vs. write, random vs. sequential, small vs. big), your multipathing setup, your use of cache, the type of disks you have, the number of disks you have, etc.

Comment on IBM DS3300 iSCSI Write Performance Solved by Alvin

Alvin — Sun, 13 Nov 2011 08:17:47 +0000

What is the maximum read/write speed or IBM DS3300 running at iSCSI connection to host?

Comment on vSphere 5 Books & Training Resources by Scott Lowe

Scott Lowe — Wed, 26 Oct 2011 12:07:04 +0000

Thanks for the recommendation on the Mastering VMware vSphere books. While they weren’t written expressly as exam study resources, many readers have commented that the books were helpful in preparing. I hope that the books prove to be useful, helpful, and informative!

Comment on vCenter Database Stats Rollup Troubleshooting by Ahmed

Ahmed — Wed, 28 Sep 2011 03:49:32 +0000

I’m writing here as after hours of troubleshooting this post fixed everything for me. A couple things to note:

The procedures may still be existing, as such you’ll need to remove them:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009857

Additionally, the queries you mention in your post will not recreate the jobs, take a look at this KB:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1004382

Comment on Storage Basics – Part VII: Storage Alignment by The elephant in the virtual datacenter room – VM alignment | Tintri blog

The elephant in the virtual datacenter room – VM alignment | Tintri blog — Tue, 27 Sep 2011 18:03:26 +0000

[...] widely discussed by both vendors (VMware, EMC, NetApp, Microsoft) and bloggers like Duncan Epping, Josh Townsend and Chad Sakac. The depth of the discussion makes it clear there’s a very real and difficult [...]

Comment on IBM DS3300 iSCSI Write Performance Solved by Panny

Panny — Thu, 22 Sep 2011 03:45:11 +0000

Thankyou for this Joshua, it really helped me!

Comment on Storage Basics – Part III: RAID by Vlad

Vlad — Fri, 02 Sep 2011 21:40:30 +0000

Hi Josh,
Thank you for the great article series!!!
Not an expert in the filed but the formula for calculation of the total IOPS for a RAID5 array, given the read/write workload percentage, looks to me more like
I=(n*i*r) + (n*i*w)/4 = (n*i)(r + w/f). Am I wrong?

Regards,
Vlad

Comment on Storage Basics – Part V: Controllers, Cache and Coalescing by Welcome to vSphere-land! » Storage Links

Welcome to vSphere-land! » Storage Links — Tue, 19 Jul 2011 21:44:23 +0000

[...] Today) Storage Basics – Part III: RAID (VM Today) Storage Basics – Part IV: Interface (VM Today) Storage Basics – Part V: Controllers, Cache and Coalescing (VM Today) Storage Basics – Part VI: Storage Workload Characterization (VM Today) Storage Basics – [...]

Comment on Storage Basics – Part III: RAID by Welcome to vSphere-land! » Storage Links

Welcome to vSphere-land! » Storage Links — Fri, 08 Jul 2011 15:12:34 +0000

[...] Storage Basics – Part I: An Introduction (VM Today) Storage Basics – Part II: IOPS (VM Today) Storage Basics – Part III: RAID (VM Today) Storage Basics – Part IV: Interface (VM Today) Storage Basics – Part V: Controllers, [...]

Comment on Storage Basics – Part IV: Interface by Welcome to vSphere-land! » Storage Links

Welcome to vSphere-land! » Storage Links — Fri, 08 Jul 2011 15:08:49 +0000

[...] (VM Today) Storage Basics – Part II: IOPS (VM Today) Storage Basics – Part III: RAID (VM Today) Storage Basics – Part IV: Interface (VM Today) Storage Basics – Part V: Controllers, Cache and Coalescing (VM Today) Storage Basics – [...]

Comment on The Skinny on ESXTOP by Duane Smith

Duane Smith — Tue, 07 Jun 2011 13:07:23 +0000

Great info! Great website!

Does anyone have the final word on making batch mode use the config file? I have not been able to limit the output in batch mode and I have not seen any posts that specifically answer that question.

Comment on IBM DS3300 iSCSI Write Performance Solved by Martin

Martin — Tue, 17 May 2011 14:18:11 +0000

Thanks a lot!!! It worked perfect for me!