Comments on: VMware ESXi 4: SD Flash in BL460c G6

By: Yassine Souabni

Yassine Souabni — Thu, 08 Jul 2010 09:50:26 +0000

Hi,
even when having small amount of servers dedicated to run hypervisor,
the “diskless server” feature enabled by implementing ESXi on SD card or Usb stick
is really intereting from the perspective of total disks cost.

Example :
for a 4 servers running hypervisor with each a couple of 146Gb 15k sas disks in Raid1
you would have to pay about (8 x ~400$)
-> about the price of a brand new BL360 additional blade + saving 1000$ !

That said, my question is related to efficiency of this config when used
in production to run several VM’s/host.

SCSI is by far more speedy than USB ctrl or SD.
So are there any I/O contraints to consider when using such solution ?
Or I’m out of subject ?

Thanks for any anwer.

By: Jason T

Jason T — Fri, 04 Jun 2010 17:34:28 +0000

I’m considering this on my DL360 G6 servers to eliminate the need for 1 (or 2 in RAID 1) 72GB SAS drives. A considerable amount of savings in purchase costs when you scale it up.

That, and I love the look on people’s faces when they see a rack of servers with no hard drives – and all the lights are green.

However, for now, I’m planning on purchasing an 8GB SD card for each of our existing servers to load up the VM Installation media for remote reinstallations. iLO remote media isn’t always as reliable as I would hope.

By: Brett Hayes

Brett Hayes — Thu, 15 Apr 2010 18:45:19 +0000

I have done the same items as you with great success. One question that I have is where have you configured the Scratch to point to? I have seem iSCSI / NAS connections for this but wondering if the SD Card can be used for this to keep it local. Thoughts?

By: Why run VMware ESXi from a memory stick or SD Card? | TechHead.co.uk

Why run VMware ESXi from a memory stick or SD Card? | TechHead.co.uk — Sat, 20 Mar 2010 17:45:42 +0000

[...] VMware ESXi 4: SD Flash in BL460c G6 – VCritical (Eric Gray) Note: Check out the photo of the new SD Slot located on the side of the BL460c – a nice feature in my opinion. [...]

By: VMware ESXi 4: SD Flash in BL460c G6 « My blog, My Precious.

VMware ESXi 4: SD Flash in BL460c G6 « My blog, My Precious. — Tue, 26 Jan 2010 12:48:49 +0000

[...] USB sticks, use SD Flash instead…. see here for more information. “HP emphasizes that only a specific model is fully supported — [...]

By: Collin C. MacMillan

Collin C. MacMillan — Sat, 16 Jan 2010 19:56:08 +0000

Note that the HP CA implies the problem is due to port proximity to other functions and NOT the fact of running ESXi on USB flash. Key to this idea is this statement about a workaround:

“Move the HP 4 GB USB Flash Media Key (Part Number 580385-B21) to an external USB port on the server. Ensure that the USB key does not interfere with closing the rear rack door.”

Sound a lot like internal shielding to me Perhaps a better grade of USB key will be the fix. Of course, changing your ESXi settings to avoid post-boot I/O to the USB key could be another workaround if I/O driven interference is truly the cause…

On the DL series, the problem is physical (doesn’t allow lid to close) so a low-profile flash will do the trick. Same proximity language with “possibility” of affect to “other electronic components” for this series too. Interesting that this did not show-up on testing at HP (flash vendor/model change in production?)

If you have the SD slot – use it. Check the SD class ratings for better performance (2/4/6 MB/sec) which can affect boot times. If you’re logging to SD, try to find a class 6 card. We’ve been running ESXi from USB flash in the lab and in SMB’s since 3.5 without issues. It is especially handy for white box lab and laptop installs where on-board HD controller may not be supported.

By: brandon

brandon — Thu, 14 Jan 2010 14:45:10 +0000

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01957637&dimid=1142777806&dicid=alr_dec09&jumpid=em_alerts/us/dec09/all/xbu/emailsubid/mrm/mcc/loc/rbu_category/alerts

By: Eric Gray

Eric Gray — Wed, 13 Jan 2010 21:10:09 +0000

Glad you liked it.

By: Kevin Houston

Kevin Houston — Wed, 13 Jan 2010 20:39:19 +0000

Brandon – do you have a link to the HP Critical Advisory you referenced?

By: brandon

brandon — Wed, 13 Jan 2010 18:38:47 +0000

Thats all great, etc, but HP recently released a critical advisory saying that the USB methods are apparently risky and can cause problems. I’m not at my usual work machine so I don’t have the advisories handy. They focus on the SD card method, which is great, but not for users who have already implemented one way on their blades, or frankly if they have G5 models (as my company does) compared to G6 models. So now I’m not supposed to use the internal usb method anymore, but I have this awesome SD card method which I can’t use at all since I don’t have the slot. HP really needs to announce that a replacement USB drive has been found that doesn’t have the problems of their original, or can ship me replacement blades. Either or.