ESX Commands – esxcfg-hwiscsi

Next in the order of commands is esxcfg-hwiscsi. This command according to the iSCSI SAN configuration guide will let you set certain settings as required by your SAN on your hardware iSCSI HBA.

esxcfg-hwiscsi -h – this is the help. Not a ton there but enough.

esxcfg-hwiscsi -l – lists the current settings.

esxcfg-hwiscsi -a – allow arp redirection on the HW iSCSI HBA. This is used be some sans to move traffic between ports.

esxcfg-hwiscsi -j – Will enable a jumbo frame (MTU 9000 bytes) when it is disabled the frame is 1500 bytes.

I will bet if these settings are required you till be directed to use them be the SAN vendor or HBA vendor. IF something bizarre is happening on your iSCSI SAN with hardware HBA’s one of these might not match the SAN.

The Forging of the new Network/VMware/Storage Professional

When I first started out in College I needed a work study job. Since I liked to help people with their computer problems I applied and was hired for a position doing phone and in person support for the University. One of the best things about starting out at a school they don’t mind teaching. Our trainer said that in previous years new employees would be slotted into being Windows or Mac or UNIX support. He said we would be Wunder-Cons (our title was consultant instead of help desk dude). We had the privilege of having to support all of it. This thrust me into the world IT no matter what the piece of paper from USC said I was a Bachelor of.

I believe a new kind of Wunder-Consultant/Engineer is being made. With the announcement of the Nexus 1000v last fall the line between Network Engineer and Datacenter/Server Engineer is getting blurred. The SAN and Server Engineers have had this tension for a while now. Virtualization is a fun technology to learn but who gets the responsibility? I have seen where the SAN team owns the ESX’s and the Server team operates the VM’s like they are physical. The Network team not trusting or understanding why they want a bunch of 1GigE trunk ports. Across larger organizations it would look different but the struggle may be just the same. Who is in control of the VM’s? Are they secure? Who gets called at 1am when something dies? This is internal to the IT department and does not consider that Sales doesn’t want to share memory with accounting.

I can see these technologies pushing engineers into being jacks of all trades. To be a truly Architect level in VMware today you must be awesome with storage and servers. You have to be able to SSH into an ESX, choose the right storage for an application, and setup templates of Windows 2003. That is an easy day. You already will have to troubleshoot IO (because all problems get blamed on the virtualization first).

With the Nexus 1000v I picture the Virtualization Admins learning the skills to configure and troubleshoot route/switch inside and outside the Virtual Infrastructure. Add to that Cisco’s push this year with 10GigE and FCoE and their own embedded virtualization products. The lines between job duties are getting blown away.

Who is poised to become the experts in this realm? The network, server or storage admins? In this economy it may be good to know how to do all three jobs. I am sure corporations would love to pay just one salary to perform these tasks.

Randomly I though how would this relate to SOX? Could it pose any problems with compliance? I will save that for next time.

From Professional VMware – Virtual Machine Disk Sizing Tool

Cool Sizing spreadsheet I found at
Professional VMware

“This is a tool that I created a while back to assist in sizing needed disk space in a deployment. Straight forward to use, the totals are calculated as follows: VMDK Size + Ram Size * 1.1 + 12Gb = Total Needed. While the VMDK may be obvious, the others are just as important. Ram Size is included, as ESX will create a swap file on the disk where the VM’s configuration resides (unless you specify otherwise) and needs to be included. The * 1.1 is to add 10% to the overall solution, to allow for snapshots. This can likely be adjusted up or down depending on your specific requirements, but I’ve found that at least 10% works best. The last number, 12GB. This one may seem like a mystery, and likely it is.”

I love good tools and tips like this. This comes from someone that has to plan and design the disk space usage well.

Don’t Delete anything. Ever!

Ok, so after a stressful morning I am writing mainly to tell myself never delete anything, ever again.

Anyone else, if you don’t know vmware very well, don’t try to manipulate your vmdk files. Probably should not perform this combo of commands:

1. snapshot
2. snapshot
3. revert to here.
4. extend disk
5. extend disk
6. extend disk
7. Call consultant and say you don’t know what happened it just isn’t working.

Extending a vmdk is not instant, and requires additional steps in Windows to actually see it work. Please please please start using VCB to backup your vmdk’s. Plus Backup Exec needs to do a SQL backup if you want your databse to work again.

SRM in a box – part 0

Several people have posted about SRM in Workstation. I decided to try it out. I do not have access to any NetApp storage device so I am trying to use the EMC Celerra Simulator. Wow, pretty intensive. I am moving it all to my laptop that has more ram. Hopefully I can get all teh VM’s to boot. Then we will see what happens.