It seems that there is an issue between the Western Digital RE3 SATA drives running at 3 Gb/s in Intel’s hot swap expander backplanes.
Root Cause
The SAS expander chip on Intel® Server Drive Enclosure AXX6DRV3GEXP and AXX4DRV3GEXP experience an undesired flow-control behavior when connected to a SATA disk drive running at 3.0 Gb/s. Drives operating at 3.0 Gb/s may not receive proper data or SATA flow control and may result in a timeout error. There is no timeout at 1.5 Gb/s. This interoperability limitation of the SAS expander with SATA disk drive is currently seen on Western Digital’s RE3 series SATA drives.
Products affected:
- Intel Server Drive Enclosure AXX6DRV3GEXP
- 6 drive expander backplane.
- Intel Server Drive Enclosure AXX4DRV3GEXP
- 4 drive expander backplane.
To mitigate the issue the drive needs to be set to run at 1.5 Gbp/s by setting the jumper at position 5/6.
It is also important to make sure that the hot swap backplane has the most current firmware.
The hot swap backplane firmware download link can be found on the server chassis support page.
SATA vs. SAS
As a rule we no longer use SATA drives in any of our server configurations.
With the cost of SAS drives having come down quite substantially over the last few years along with the huge performance benefits we get with using SAS drives there is really no reason to use SATA drives in a server setting anymore.
The exception to this rule is for Intel Solid-State Drives that run with a SATA interface.
Philip Elder
MPECS Inc.
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book
*Our original iMac was stolen (previous blog post). We now have a new MacBook Pro courtesy of Vlad Mazek, owner of OWN.
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