4TB HGST Ultrastar 7K4000 shows as 2 TB with Dell PERC 6/i RAID controller

Question

I just got 2 x HGST Ultrastar 7K4000 4 TB drives, for creating a RAID 1 array in a Dell Poweredge 2950 server with a PERC 6/i RAID controller.

According to a Compatibility Summary from HGST, the drive should work with a non-reduced capacity.

However, upon installation, the drives show up with a 2 TB capacity in the RAID configurator, rather than 4 TB.

What does it take to get the full capacity from the drives? Do I need to somehow modify the emulated/reported sector size?

Solution 1

You have to be careful with disks larger than 2TB on older controllers. There's no way to see the full capacity of 3TB, 4TB and 6TB disks on the Perc 6/i RAID controller, and Dell does not offer a firmware upgrade that would enable that functionality. Unfortunately, the chart from HGST is incorrect.

The root issue is that the chipset on the 6i controller is the LSI SAS1078 is limited to 2.2TB and 2^32 512K sectors. This is older-generation gear from 2006-2009, so it's not a future-proof as it could be.

However, there are many inexpensive replacement drop-in controllers that can accommodate these drives. If the capacity is important to you, any modern LSI or Perc controller will do the job, but you'll also need to change the internal cabling...

Solution 2

As per http://en.community.dell.com/support-forums/servers/f/906/t/19412446 the perc 6 only supports 2TB physical drives

Comments

[ewwhite]

Are you using the SATA version of the disk or the SAS version?

[crishoj]

@ewwhite SATA version