VMware Cloud Community
dtdionne
Contributor
Contributor

ESX diskless install/booting

Greetings,

Please tell me that there is a secret undocumented way to install and boot ESX 3.5.x via software iSCSI. Hopfully by utilizing the CLI during the install or something?

PLEASE!!!!!

If you have to lie to me....LIE!!! but just tell me I can.... booohooohooho

FWIW, I do not like the new forums...yet, i guess, maybe they'll grow on me.

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6 Replies
mcowger
Immortal
Immortal

Not via software iSCSI, nope.

--Matt

--Matt VCDX #52 blog.cowger.us
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dtdionne
Contributor
Contributor

Shitaki!!!

Well, you all can know one thing for certain....someone's gonna be tryin that latter on tnite, I know I wont be successful but at least if/when i get my fanny handed to me, I'll have some supporting evidence.

What's the best, cheapest highest density iSCSI HBA? If there is such a thing...

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fejf
Expert
Expert

Hi,

as mcowger said it's not possible to boot via software iSCSI initiator and I want to tell you why:

If you want to access iSCSI you need a network (TCP/IP) stack (software) which can send SCSI commands via a network card (put SCSI commands inside TCP/IP-network packets). This could be done in the following ways:

1. you program the tcp/ip-stack into the bios (I never heart of such a thing)

2. you program the network-card bios to include the tcp/ip stack (wait - that's called an iSCSI HBA Smiley Wink )

3. you use the pxe feature of your network card to download the kernel and an initial ramdisk which includes the necessary software to load the rest - this can be done for a windows remote boot with e.g. neoware image manager or emboot. For Linux you can build your own initrd to do this, but there is no possibility to do this in a supported way with esx and i don't think there's an unsupported way), because the service console is also a kind of a virtual machine and you would need to modify the VMKernel to make this work

There are few iSCSI HBAs which work for the ESX server. See the I/O HCL: http://www.vmware.com/pdf/vi35_io_guide.pdf (search for QLogic or iSCSI, Page 21)

--

There are 10 types of people. Those who understand binary and the rest and those who understand gray-code.

-- There are 10 types of people. Those who understand binary and the rest. And those who understand gray-code.
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dtdionne
Contributor
Contributor

FWIW...

1. All DEC Alphas had TCP/IP enabled bios's going back to the early 80's but that isnt the issue here...

2. I dont see why they just dont include iSCSI support in the anaconda/busybox installer...i bet thats what they end up doing anyway.

3. I've got both RIS servers and PXE servers on my network but that's not the problem either, the problem is that the kernel loaded at install time does not have the monolithic iSCSI drivers loaded nor are they available via modules....actaully i have no idea what the problem really is, thats just my guess.

I dont understand your point about the vmkernel...once 3.5.x is loaded iSCSI is supported are you saying that the vmkernel is modified once you enable iSCSI?

Also, are you sayin that if i knew how to build an initrd that would load all the iSCSI stuff and boot from PXE that this would be possible for me? Cause I do know how to do that....

GREAT DISCUSSION THOUGH!!! I really appreaciate it and sorry for being so blah about it, im wiped out

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fejf
Expert
Expert

I say that you need to see the service console just like another virtual machine (but with more permissions) that uses the vmkernel to access hardware. You also need the vmkernel PLUS the service console to access an iSCSI target. That's what makes it difficult. The VMKernel provides the connection and virtual NIC for the service console while the service console is the one that needs to intialize the connection (and e.g. authenticate etc.)

So you need the vmkernel + part of the service console running to access an iSCSI target.

--

There are 10 types of people. Those who understand binary and the rest and those who understand gray-code.

-- There are 10 types of people. Those who understand binary and the rest. And those who understand gray-code.
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dtdionne
Contributor
Contributor

yep yep...your exactly right, damnit!! ok, listen fejf!! I'll have no more of this being right crap! For starters it means i cant do what i want and further more it makes me wrong and i just wont stand for that! hehe, thanks man...u just saved me a decent amount of time.

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