Can I use TCP/IP instead of LLT and GAB for heartbeat link

[Bashir_Gas]

I have installed VCS 5.0 on Solaris 10 with 2 nics (1 public and 1 private)
The private link use as recommended llt and gab.

Can I change the current configuration based on LLT and GAB into TCP/IP ?

Will my VCS still work?

// Bash

[Gene_Henriksen]

Why? TCP/IP has much more overhead. You can run your links over the same links as TCP. Multiple protocols can work on the same NIC and network. Just configure IP addresses on the ports used for LLT. We recommend that one should be devoted to LLT only, but all others can use the same links. In our mobile classroom where I only have two ports on Tadpole SPARC laptops, I have taught GCO with LLT runnning over two public ports with IP also running.

While we allow UDP, TCP isn't the way, and UDP is not recommended.

[Bashir_Gas]

If I can configure IP address on the same port used LLT then that is great (Y),
because I want to use the same port for iSCSI communication with iSCSI server.

You have once again answered my question correct.

Thanks
Bash

[Gene_Henriksen]

You can configure IP on same port as LLT. Just like Windows NT 3.51 allowed you to have IPX/SPX, NetBEUI and IP all on the same port.

If the data flow from iSCSI is very heavy, you may experience LLT packet delays. That is why you have 2 links.

[Hywel_Mallett]

As Gene says, LLT is designed for this application, to provide low latency. If it ain't broke, don't fix it ;)

[Gene_Henriksen]

We have the ability to use UDP, but experience shows that a routed protocol can cause problems when someone changes routing. One cluster, for example, with servers sitting next to each other switched from LLT to UDP and immediately experienced problems with packet delays. It turned out the packets were being routed to another data center and then back.

Don't mess with what works reliably.

[Bashir_Gas]

Guys,

I know you are right about everything you said.
Due to lack of hardware I have to set IP address on the LLT interface.
BTW, this is only a test server and for this task I want to setup iSCSI
towards a linux box via a gigabit switch.

Gene,

You said before that VCS must own the disks in order to
configure diskgroups. I have collegues who are working
with Redundancy web server on Windows 2003 server
and they could acheive the ownership of the disks with
their iSCSI initiator.

I have no knowledge about this and as you know we
were thrown into this project without even a preperation
like a lecture, training,etc,etc......

I really appreciate your enormous help with my issues.

Keep the good work.

Thanks
Bashir

[Gene_Henriksen]

iSCSI is a method of accessing an array over ethernet, not another system. The iSCSI method results in the same functionality as far as DGs as fiber channel. We yse some iSCSI arrays to ship our classroom gear to a customer site because we have found iSCSI much cheaper than fiber and we use laptops for on-site classes and they cannot use a fiber HBA.

You cannot do iSCSI to a Linux box because Linux is not an array. You would have to share the Linux filesystems. If the Linux box is accessing an iSCSI array, then perhaps you can do that also.

Just out of curiosity, where are you located?