can I only create ONE raid array on mtp controller?! blade server with storage expansion unit 2


I've a IBM bladeserver 8843 with 2 u320 scsi discs, this discs are in an raid 1 array, builded on the onboard mtp raid controller. Worked fine over years. Bescause I need more space for my files on this server I've bought the ibm "storage expansion unit 2" and 2x 300gb u320 scsi discs. The manuall says that I had to activate the 2nd raid controller on the mm but I didn't found it, so I booted my server with appended storage unit and go into the raid bios but I was not able to create a new array as I do it usually on my "big" servers.

Ok so I booted the blade server with the raid cd from ibm which came with the storage expansion unit, in the raid manager it was also not possible to add an new raid array. So I deleted the existing array and tried to create a new one but it was only possible to create one array. Stupid. So I called ibm for help, but the said that my guarantee (and support) ended 3 weeks ago for this server so they can't give me a answer (really cheeky - I've own over 35 ibm servers).

So I offer 500 points for the solution. According to the manual it should be possible. At the moment I builded a raid 1 with the new 300gb dics and run the os from only one onbord disc but thats not good, I need raid 1 safety also for the OS disc.
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I fear the worst here, and you can only create one RAID array with the mtp controller.  If you want more arrays, you'll need other methods, like another card or software raid.

Here's the documentation:

"It is possible to use two internal SCSI SFF hard disk drives and a BSE-II Unit with two hot swappable hard disk drives at the same time, providing more local storage capacity. The BSE-II unit uses the onboard LSI 53C1020 SCSI controller of the 8843 blade server.

However, it is only possible to create one RAID array with all four hard disk drives, for example, creating a RAID-1E. If you have 2 disks, it is a RAID-1 mirror. If you have more than 2 disks, they can be used as additional single disks, a hot spare, or included in the array. So, for 3 drives, you can have a 3 drive RAID-1E, for 4 drives, a 4 drive RAID-1E, or a 3 drive RAID-1E with a hot spare drive."

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seechillerAuthor Commented:
Thanks brain2000 for your answer! Stupid! I've invested over 1200$ for this and I can't create two raid arrays, just stupid. I'm very **** about this....

Another qustion, I've setup the server new from scratch with the new 300GB drives as /home (raid 1 with the mtp raid controller) and the 2 old u320 drives (onboard - with software raid) as OS drives. Do you think that is the right setup or is ist better to use the raid controller for the OS drives instead of the file drives?
I'm sorry to hear that.  We've all made expensive mistakes.  At least it wasn't a $12,000 mistake!  Besides, software RAID 1 is pretty low overhead, so unless you are maxing out your server's bus and CPU already, you won't even notice it.

Your RAID setup should work just fine.  Just keep in mind that software RAID is sometimes funny during boot if one drive is bad.  If you get a bluescreen "Inaccessible boot device" You may have to swap the two drives to get the system booting depending on which one fails.  Hardware RAID masks that layer for booting the OS.  I have used software RAID for all my system's OS drives for the last 8 years.

Just make sure you check the RAID drive's health periodically.  There's nothing like losing one drive one month, then another drive the next month, and wondering why the RAID didn't help you out.
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