iSCSI and crossover cables

[cariparo]

Hi All,

I have 3 phisical server each with esxi4 and one shared storage (win2008 storage box) with 4 gib nic's

I'm thinking to connect each server with a crossover cable to the storage and use iSCSI protocol to map the disks.

I read somewhere that crossover is not supported and it slow down the performance.

Does anyone have more info or experience about it please?

Thanks in advance

Carip

[DSTAVERT]

Set it up ant test. Get a switch and set that up to test. Compare.

[jfelinski]

Hi,

Since Gbe Ethernet cards has been released, you no longer need a crossover cable to connect them. Devices will negotiate on standard UTP 5 cable.

With configuration you've described, this will work, however you'll have one path from each host to the storage. From redundancy and multipathing point of view, this is not recommended.

---

MCSAS,CompTIA Security, VCP

[cariparo]

Thanks,

I didnt think about multipath... i will setup a GB switch.

Carip

[AlbertWT · Accepted solution]

Hi Cariparo,

Of course you can do it, see the following diagram this is what I'm using now.

a direct connection from the SAN into the ESXi servers without anything in the middle, this can eliminate the single point of failure caused by the Switch and also provide redundancy.

each color in the iSCSI network is different IP subnet by itself. from the ESXi into the production network i put two cable connected to two different ports and then add those pNIC into same vSwitch for failover

hope this helps,

any comemnts and input would be greatly appreciated.

Kind Regards,

AWT

[cariparo]

Thanks Albert,

you are using what more or less is on my mind, with the difference that I want to virtualize DCs and Exchange also.

(but in some esx3 official forum I read that cross cables isnt supported...)

Question solved.

Now i'm investigating about new features of esxi iSCSI initiator.

I'm trying to discover if the "problems" described here:

http://virtualgeek.typepad.com/virtual_geek/2009/01/a-multivendor-post-to-help-our-mutual-iscsi-cust...

was solved in this new version.

Jumbo frames support in vmkernel seem solved, now I'm looking for info abt multiple sessions or connections, similar to Microsoft initiator, to best aggregathe the transfer rate. (each of my server have 4x1Gb card dedicatd st SAN)

If I discover more info I will update this thread.

Thanks,

Cariparo

[cariparo]

Sorry, some internal server error cause multiple post

[cariparo]

Sorry, some internal server error cause multiple post

[pie8ter]

We are looking at the setup like yours. We are planning to purchase about six Dell servers to replace our old servers and one MD3000i. Are there enough network ports in MD3000i to connect six servers?

We also have Backexec 12.0. Does it support backing up VMs?

Thanks

[AlbertWT]

Hi Pieter,

AFAIK, MD3000i can only have 2 GBNIC on each of the Storage Controllers so maximum is two.

without the switch it can only support two hosts.