[lug] Mixing SSD and HDD in Dell R310 server

[scott.herod at comcast.net]

Hello all,

I've been beating my head against this for hours.  I've got two Dell r310 1U servers.  They have four drive bays which are cabled directly to the motherboard. In bay A I have an HDD which has CentOS 6.2 installed.  In the other three bays I've placed three Crucial 64G SSDs that I'd eventually like to configure with Raid 0.  Neither server will boot if I enable the SSD in bay C.  The boot order is set to boot from disk only with bay A at the top of the list.  The SATA controller is set to ATA, not RAID.  BIOS boot is turned on (rather than UEFI.)

The system boots fine if either or both SSDs in bays B and D are enabled.

Occasionally the system will fall into the GRUB menu so it must recognize bay A as containing the boot disk.  Every once in a while it will actually find and run load the kernel.

Curiously, when I enabled the SSD in bay C through the BIOS, Dell's hardware diagnostics tool saw neither it nor the HDD in bay A.  With the SSD disabled, it recognized the HDD in bay A and the SSDs in bays B and D.

Could the speed difference between the HDD and SSD be confusing the system?  I've not tried putting an HDD in bay C or moving the HDD from A to B to see if then D causes a problem.

Thanks,

Scott