Software SAN as VM - using local storage - vmdk or rdm - file/block size?

[JaapL]

Hi all,

I 'm testing Starwind, software SAN, on a ESXi4.0.x host with only local disks (3x 640Gb) - no supported raid controller (yet).

Something like StorMagics SvSAN

If all works well a second host will be added to test redundancy further.

Starwind is installed as VM under W2K8..

I want to add storage only to Starwind and use that iSCSI storage to add VMs

I could add harddisk as .vmdk to Starwind or use virtual RDM.

It doesn't seem logical to add storage as .vmdk, create an Starwind ,img in it, and then create a client .vmdk in it.

However RDM is not available, grayed out, when trying to add a local harddisk to the Starwind VM.

Untill I turn on a host with iSCSI. Then it is available.

1. Is it correct that the rdm option only is available when using raid or (iscsi) SAN ?

I want to use the entire disk (640Gb) as storage. The default choice is 256Gb/1Mb file/block size.

2. Is there any issue when I choose a higher file/block size?

To use up 640Gb I would have to choose the 1024Gb/4Mb file/block size

Other options/issues is should worry about trying this?

Thanks

Jaap

[binoche]

However RDM is not available, grayed out, when trying to add a local harddisk to the Starwind VM.

Untill I turn on a host with iSCSI. Then it is available.

1. Is it correct that the rdm option only is available when using raid or (iscsi) SAN ?

[] correct, rdm only supports remote lun such as iscsi lun, fc lun

I want to use the entire disk (640Gb) as storage. The default choice is 256Gb/1Mb file/block size.

2. Is there any issue when I choose a higher file/block size?

To use up 640Gb I would have to choose the 1024Gb/4Mb file/block size

[] correct, another option is 2TB/8MB

[JaapL]

Hi,

An added question :).

Do I have to allign the .vmdk/rdm disk to get performance optimal?

Thanks,

Jaap

[binoche]

let VI Client do it for you, 1MB by default

binoche, VMware VCP, Cisco CCNA

[PaulSvirin]

2. Is there any issue when I choose a higher file/block size?
To use up 640Gb I would have to choose the 1024Gb/4Mb file/block size

Are you asking about problems on higher block sizes?

Just contacted testing team and they did not report about troubles in this case.

---

iSCSI SAN software

http://www.starwindsoftware.com

[AnatolyVilchins]

Hello!

RDM is not actually best option, but still. I will sugest you to take a close look at StarWind iSCSI SAN: Best Practices Guide, at the Performance pages.

Feel free to contact me via e-mail ( anatoly.vilchinsky@starwindsoftware.com ) or our company tech support

About what binoche said: you should remember that in case if you will choose 4MB block size file will take this space, even in case if its size will be much less.

King Regards

iSCSI Software Support Department

http://www.starwindsoftware.com

[JaapL]

Hi all,

(Solved problem with connectivity > creted VMkernel ports for vSwitch1 - Storage)

I have the following with this config:

ESXi v4.0.1 host with as VM installed > Starwind v5.2

•I added two of the local host disks to Starwind VM.

•Formatted both disks as simple volumes from within Starwind VM

•Created two seperated .img files in Starwind

•Rescanned the storage adapters and they are there

Problem arises when I tried to add storage using these storage adapters > unable to create partition

(See attachments)

Placed question also on Starwind forum (Constantin)

Greetz Jaap

[AnatolyVilchins]

I'm 100% sure that Constantin will take everythiing under his control. We will be glad to know about results.

Cheers!

iSCSI Software Support Department

[ConstantinV]

Dear, Jaap! Thank you for your logs of ESX and StarWind! We found that this is problem of ESX - it constantly drops the session. Now we are trying to find out what is the reason of such behavior. You can also try to contact ESX support to find out the reason of it. Anyway, please keep us updated.

StarWind Software Support Engineer