Q: Xserve 2009 4TB Drive Compatibility

28-bit LBA translates to a ~137GB drive limit, and 48-bit LBA  is 128PB. So it'd seem this isn't an addressibility problem. Are you certain the drive wasn't partitioned with MBR partition scheme? That is a 2.2GB limit because MBR supports only 32-bit addressing. Sounds like GPT wasn't used.

curious if connecting via a hardware RAID card would make a difference?

I'm certain the drive was incorrectly partitioned using MBR scheme, rather than with GPT.

I've seen several other posts indicating xserve 2009 only recognizes 2.2TB total from a drive. I was curious if anyone had tried with the hardware raid card installed. Seems short sited if engineering designed to max at ~2TB when the existing drives of the day were 2TB.

They didn't, the problem is MBR vs GPT. MBR is 32 bit addressible, which results in a 2.2TB limit. There is no such thing as LBA 32 bit addressing. LBA 48 bit addressing has been around since 2003 and before that it was 28 bit addressing from 1994. People are partitioning their drives wrong.

I find it difficult to believe anyone working with Intel  xserves would not know that Guid partition scheme (the default for Intel Macs and a requirement for an Intel Mac boot disk) would not ready have GUID partitioned their drive...

Can you confirm you or someone you know have successfully used full capacity of 3 or 4TB drives on Xserve 2009? If so can you share success brand, make, model, details. Thanks.

It could be a limitation of the ADM.