SCSI PATH TO THE INTERNAL DISKS--rp4440

[sheevm]

Hi all,

I am planning to mirror the two internal drives (root disks) to create redundancy. How the SCSI controller redundancy is is achieved for the internal disks? I just want to make sure these two disks are on separate paths.

Thanks.Raji

[Enrico P.]

Hi,
generally the rp4440 came out with the internal disk in the same path.
For separate path you need a you need to mount one ulterior card on the scsi controller.

You can check path with the

ioscan -fnCdisk

command.

ENrico

[Ninad_1]

As I can see from the rp4440 manual it can accomodate only 2 internal hard drives.
You do not have any option of having seperate paths or having different device paths - other than that provided by the hardware design of rp4440.
Thus you can go ahead and mirror - there nothing you can do to have any particular arrangement.
The only thing I would suggest is keep the main disk SCSI id higher than the disk you will use as mirror.

Regards,
Ninad

[Enrico P.]

Hi,

http://www.docs.hp.com/en/A9950-96005-en/A9950-96005-en.pdf

Look for the "Converting SCSI From Simplex to Duplex" part.

Enrico

[Torsten.]

Hi,

the default for this system is called "simplex" configuration, this means both disks on the same path. There is an option: the "duplex" configuration. In this case your are using the second SCSI controller on the core I/O card. Both disks are on a dedicated BUSSES. You need a special "duplex card" installed near the disks inside the box and you can't use the external SCSI connectors on the core I/O card anymore. (In simplex mode you can use one of them). Even in duplex mode the both SCSI controllers will be on the same card, but this will be no problem, I guess.

The alternative configuration will be an external disk using an additional controller.


If you see this hw-pathes in ioscan, your system is in simplex mode:

0/1/1/0.0.0 = disk0
0/1/1/0.1.0 = disk1

difference in duplex mode:

0/1/1/1.0.0 = disk0

HTH!

[sheevm]

Thanks for all of your responses.
Just an FYI

I found this Document in the HP website talks about Internal dual channel SCSI controller on rp4440 servers.

-----------------------------------


Hot-plug disk drives

The HP 9000 rp4410-4 and rp4440-8 Servers support up to two SCSI disks, and the HP 9000 rp3410-2 and rp3440-4 Servers support up to three. All disks are accessible from the front of the system and can be removed (or hot-plugged) while the server continues to run.
A dual-channel SCSI controller manages the pair of disks in the HP 9000 rp4410-4 and rp4440-8 Servers. The disks can be configured either both on a single SCSI channel or one disk on each of the two channels, with disk mirroring for added availability. When only one SCSI channel is used for the disks, the second can be connected to an external device such as a tape drive.
A single dual-channel SCSI controller manages the three disks in the HP 9000 rp3410-2 and rp3440-4 Servers. One channel links to two internal disks; the second channel is connected to the third internal disk. This allows disk mirroring across separate SCSI channels, further enhancing availability.
An optional dual-channel Ultra320 SCSI RAID controller provides RAID1 support to the internal drives of the HP 9000 rp3440-4, rp4410-4, and rp4440-8 Servers.
25

[Torsten.]

Just what I told you.

Points are always welcome

;-)

[sheevm]

Thanks. I submitted the points and closing the thread.