best practise on iSCSI initiator Multipath inside a VM

[sgul]

Hi,

Could someone comment on the best practise on using Multipathing inside a Win2008 VM.

I'm wondering if there is any speed or performance gains if I setup two vNIC's and then enable Multipathing on them via the iSCSI initiator.

We're connecting to iSCSI volumes on an Equallogic array.

Appreciate any comments and thoughts.

cheers

[dilidolo]

Here is what I can think about

1. either use trunking/etherchannel for vswitch or use seperate vswitches for the vnics inside VM

2. avoid routing for iscsi traffic

3. use jumbo frame

[Texiwill]

Hello,

Moved to Virtual Machine and Guest OS forum.

I would investigating using iSCSI initiators from ESX to gain some builtin capability such as multipath instead of placing it within a VM.

Best regards,
Edward L. Haletky VMware Communities User Moderator, VMware vExpert 2009

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[sgul]

thanks for the response.

as I want to access large luns and leverage Equallogic features, I've been advised to use iSCSi initiators inside the VM to access the LUNS.

What I can't figure out it if there is any benefit inside the VM to have two virtual NICs connect to the iSCSI storage and then enabling MPIO on these virtual NICs. theorically it sounds like a viable option but not sure if it used in practise.

On a physical Win2k8 server it is recommended to have multiple NICs connected to iSCSI storage with MPIO enabled for good load balancing and failover.

Does the same apply in a Virtual machine environment, is the question ?

[Texiwill]

Hello,

To gain this usefulness you would need to have 2 vNICs each connecting through different portgroups to different pNICS attached hopefully to different vSwitches. Also, remember, any IO you throw through the vSwitch impacts all VMs on that vSwitch and the entire host.

You gain redundancy by having multiple pNICs per vSwitch.... In either case I would have a vNIC just for iSCSI traffic if you go this route. Hopefully on an entirely different network than your non-iSCSI systems.

Personally with ESX 4 and MPP capabilities plust load balancing, etc. Plus the iSCSI improvements, I would let ESX handle it instead of trying to manage it withing the VM and ESX.

Best regards,
Edward L. Haletky VMware Communities User Moderator, VMware vExpert 2009

Virtualization Practice Analyst[/url]
Now Available: 'VMware vSphere(TM) and Virtual Infrastructure Security'[/url]
Also available 'VMWare ESX Server in the Enterprise'[/url]
[url=http://www.astroarch.com/wiki/index.php/Blog_Roll]SearchVMware Pro[/url]|Blue Gears[/url]|Top Virtualization Security Links[/url]|
[url=http://www.astroarch.com/wiki/index.php/Virtualization_Security_Round_Table_Podcast]Virtualization Security Round Table Podcast[/url]