ML370/P400 – more than 8 drives in one array? | SQL Server Performance Forums

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ML370/P400 – more than 8 drives in one array?

Based on the posts in this forum, we ordered several of the new ML370s and are trying to configure them properly. We have 16 SAS SFF drives, the second drive cage, and a second P400 controller. I need to create a single array across 12 drives. Currently, each controller card has two ports. Each port is connected to one half of the drive cage. In the array manager, each controller only has access to 8 drives. My system guys and our VAR said 8 is the max for the controller but the spec page for the P400 indicates that it can connect to a maximum of 18 drives:…artarrayp400/index.html?jumpid=reg_R1002_USEN Any ideas?
Is there a way to jumper the cages so that one connection controls all 8 drives?
Is there some type of expander cabling from HP that will allow this controller to connect to 18 drives? I appreciate any help you may have. Thanks,
HP Smart Array controllers should let you put as many drives as you can connect in one array
or alteast 56 for their RAID 6 ADG
they recommend max of 14 for RAID 5 of course, this means actually connecting 12 or 16 to one controller
it sounds like you connected each drive bay to its own controller
which means there 8 drives per controller depending on whether you have 1 P400/i and 1 P400, or 2 P400
the 400/i can only connect to 6 if you do connect both bays to one P400, you lose the benefits of dual controllers personally, I recommend distributing disks across multiple controllers
and this implies splitting a db across multiple files
Thanks Joe. I’ll plan on splitting the array across the two controllers. It looks like the P400 supports 18 drives, but you need to have the ML570 to do so. It has one cage that holds 18 drives and connects to the controller with a single cable. The cage must have some type of expander chip inside.