SUMMARY:A5200 fail over plan question

From: yhe@jhmi.edu
Date: Sun Mar 26 2000 - 22:04:53 CST


Dear Sun Managers:

Thansk for the all responses, they are very helpful. I am attaching the
responseswhich include both question and answers, sorry if I miss anyone.

thanks for:

 Stuart Whitby <swhitby@Legato.COM>
Arthur Darren Dunham <add@netcom.com>
Rasana Atreya <rasana_atreya@hotmail.com>
Danny Cox <dannyc@pcs.co.uk>
Thomas Anders <anders@hmi.de>

> I have A5200 is current connect with E250 system( will be/planing to
> upgraded to UE5500), my fail over plan is to have A5200 connect to
another
> E250 system(hardware is ready) and install VM, when 1st server is down
> i can bring the 2nd one up as soon as possible. To reduce the down time
> as close to "0" as possible. The questions are:
>
> 1. Can 2nd E250 connect to A5200 and configure it when the 1st one is
> alive? Will this effect the data on the array?

Answer1:
Probably. There's an article on sunsolve for changing the scsi
initiator address on a sun so 2 can be connected to the same bus and not
have a problem. You'd probably need to shut down the running system to
actually connect the backup though.

answer 2:

Two major things to watch for - disable DMP drivers (to work round
a very irritating bug) and make quite sure your A5000 patch matrix is
installed completely and bang up to date including 107280 which is
particularly needed for multi-initiator setups using the PCI bus
based machines.

> 2. Can both E250s access the A5200 at same time?

answer 1:
In an electrical/scsi sense, yes. From a VM sense, not really.
The disk group will not work properly if you try to import it onto two
hosts simultaneously.
answer 2:
No. You will run into extensive file-locking issues, and issues
with the inode table. In truth, you can do it, but you will get
far too many problems to make this worthwhile.

> 3. The 2nd server is on production also, does license code bind with
> hostid/name/ip/etc, since two systems are different hostid/name/ip, can
I
> use the same license code or I need to buy the 2nd license( this may be
> the question for Sun?)?
There are two types of licensing for Veritas. You can see what you have
by doing a /usr/sbin/vxlicense -p

The first (and most common) kind is a host based license. If you need
to transfer it to another host, contact Veritas. You should be able to
fill out a form to request the license transfer. You normally fill out
an affidavit that you will not run the old license on the old machine.
Then they send you a license for server #2.

The other type is based on the storage array connected. If you have
that, then veritas enables itself at boot when the device is visible.
If you have that, then you should be able to install veritas after the
device has been attached to server 2.

if you use /usr/sbin/vxlicense -p
and see you have Photon license then you do not need worry about it.

> 4. How and what is the best way to do it beside the clustering system.

answer 1:
Without any sales push, (I'm in tech support) we've got a
cluster product specifically for this. Have a read through the
documentation, and see which of your questions this answers.
Have a look at www.legato.com/products/index.html on the cluster
product, and maybe replication if you agree with my answer on
question 3.

answer 2:

If you get them connected..

system1, shut down applications, unmount filesystems, export disk group.
system2, import disk gropu, mount filesystems, start applications.

------------------------------------------------------------------------------
Xueying "Ying" He voice (410) 614-8765
Network Security & Enterprise Services Administrator fax (410) 614-0434
The Johns Hopkins Medical Institutions yhe@jhmi.edu



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:14:05 CDT