Smart Array 5i did something weird

[Rose_Harris]

Hi folks,

I have a ProLiant DL380 G3 with Smart Array 5i.  I setup a single disk as RAID 0 and in my OS began to use the raw device (unpartitioned).  Everything was fine between reboots and so on, until I put the disk in another server (identical model) and added the disk in Smart Array 5i exactly as I had in the first server.  However I was very shocked to discover in my OS that the first 1MiB of the disk had been wiped to zeros!

Why did this happen?  Is there a way to stop it?

I consider myself lucky that I was able to recover all my data.  I find it quite shocking that Smart Array 5i didn't give me any warning but just went ahead and blanked the first 62 sectors of my disk (and considering it's all 0x00's, there seems to be no purpose to this).  It worries me that RAID controller would just start overwriting raw disks.  Not all disk uses require partitioning.

Any thoughts on why this is the case?

Thanks,

Rose

[Jimmy Vance]

If I'm reading your message properly, when you moved the disk to the other system, you went into ACU and added the disk.

When moving disks between systems, the Smart Array will recognise the array settings on the disk automatically. If the array controller didn't see that the drive had already been created as an array, the likely cause was the second server had older controller firmware. If you had to "create" the array in the 2nd system you effectively wiped out what was on the disk.

[Rose_Harris]

The ACU was pressing F8 from the BIOS, just to clarify.  This is where I set it up.

It didn't wipe the whole disk, just the first 1MiB also just to clarify.

As I was using the whole raw disk there won't have been any information on the disk to identify to the subsequent Smart Array 5i devices how the disk was configured.  Is this what it tries to store in the first 1MiB that got wiped when I set it up again on the second server?

If so, how come it was just entirely blank 0x00's and contained no actual signature or data of any kind?

Is there a way to use a disk in my ProLiant as just a raw disk without having to use RAID.  Can Linux access the raw disk even if a logical volume hasn't been setup in Smart Array 5i?

Thanks for all your help so far

[Jimmy Vance]

Smart Array controllers write the RAID configuration information to what is know as the "RIS" (RAID Information Sector) area on the disk. The controller reads this information at every boot. The information stored here allows you to replace a failed controller, or to move the drives to another Smart Array equiped system.

"P" series Smart Array controllers only provide RAID functionality, there is no pass through mode. The closest you can come to presenting a raw disk is just to create an 1 disk array with 1 logical drive, basically create a bunch of single array JBOD devices.

 The "B" series controllers can be set to RAID mode, or plain SATA mode in the BIOS. Some of the older "100 series" ProLiant servers also had a BIOS setting for RAID or plain SATA. This group of controllers requires a closed source driver that is only available  for Windows, Red Hat and SUSE when used in RAID mode.