How Autodeploy differs from building host from WDS

[vDeepak]

How Autodeploy feature differs from building host from WDS...I have built lots host with WDS (MS solution) i.e W2k3, W2k8, ESX etc..WDS provides a platform for Network Boot. So why should one go for Autdeploy feature?

[vDeepak]

Any updates?

[chriswahl]

If I recall correctly, WDS performs a thick install to disk. AutoDeploy is a stateless deployment of either the default VMware ISO or a custom built ISO using vSphere Image Builder, and lives in the host's memory.

[vDeepak]

ok, but can you explain "Thick" install and "Stateless " Install here?

[john23]

For stateless install: http://pubs.vmware.com/vsphere-50/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-50-install...

[vDeepak]

ok, as per the pdf...the stateless intall means image can be load in memory. However at the end we need a storage (boot lun etc) which can hold the ESXi5 installer files (etc,vmfs var , etc). So again the disk is required.

Can someone explain how its a stateless way and again how autodeploy differs from rest of PXE boot technologies.

Thanks

[chriswahl]

Have you ever booted a server from a CD, such as a Linux recovery disk? The entire OS is loaded into memory, not onto disk, and is lost when the server is reset. This is basically how AutoDeploy works, except instead of a CD it uses PXE to load the ISO image onto the host.

AutoDeploy uses PXE to load the ISO image so that the hypervisor (ESXi 5) is loaded into memory and is lost on reboot. It does not install anything onto the host's disk, and is therefore stateless.

The rest of the PXE boot technologies typically install the hypervisor directly onto local disk.

If you want the hypervisor loaded onto local disk, AutoDeploy is not what you're looking for.

[vDeepak]

ok, that make more sense..so if we say with Autodeploy ESXi5 actually gets installed it to Memory and boot LUN (as we have boot from SAN) is actually not required here.

And if directly goes to memory, does it also consumes there and effect the total available memory to VM's?

[ranjitcool]

No, Esxi itself has a very small foot print and this will not affect any memory. I would go with predeploy because any changes you would do - you just have to update host profiles and the profile is loaded on the reboot.

R

[vDeepak]

1. Does the ESXi 5 footprint remains constant in the host memory. I mean if i reboot host does the image remains there?

2. Regarding updating host through host profile: Is that not available in earlier versions..eg I have two 4.1 hosts (ESXiA and ESXiB) and i update one (ESXiA) 4.1 to 4.1 update 1 and created a profile and if i apply this profile to host 4.1 (ESXiB) then does that not upgraded to 4.1?

Bit confused about these...much appreciated your help.

Thanks

[AnthBro]

Yes it is loaded to memory.

And yes that memory can't be use by VMs, however as ESXi is very lightweight it takes less than 200mb of memory.

It is advisable the other functions that would usually also go on the install disk are offloaded by having an external dump collector and syslog collector so this space isn't required in memory.

Autodeploy uses a pxe boot process, so you can rebuild anything with stateless but it must be set to pxe boot first every time.

See Autodeploy doco for more information.

[AnthBro]

ranjitcool wrote:

No, Esxi itself has a very small foot print and this will not affect any memory. I would go with predeploy because any changes you would do - you just have to update host profiles and the profile is loaded on the reboot.

R

ranjitcool that is incorrect, though ESXi is itself lightweight, when it is deployed into RAM using the stateless option of autodeploy it DOES take up memory that other VMs cannot use, less than 200mb.