Disk Enclosures
1748136 Members
3831 Online
108758 Solutions
New Discussion юеВ

Re: One SAS drive reporting lower transfer rate

 
SOLVED
Go to solution
rocru
Occasional Contributor

One SAS drive reporting lower transfer rate

Configuration:

 

P2000 LFF scaled down to two (2) D2600 in a daisy. All slots (36) filled with Seagate (HPs) ST3450857SS 450GB 15k SAS DP drives. Each port on the dual port controller is capable of 6Gb/ps transfer rate, however....

 

One drive (out of the 36) is reporting a 3.0Gb/ps transfer rate; reporting found using the P2000 SMU.

 

Why would the one drive report a lower transfer rate? 

 

I presummed a port failure, but the drive should still push 6.0Gb/ps.

 

Additionally, am I correct to assume that if one (1) drive, in a 12 drive RAID LUN, is transfering half of the data, the entire LUN will suffer?

 

 

3 REPLIES 3
AnkitM
Trusted Contributor
Solution

Re: One SAS drive reporting lower transfer rate

Drive changing speed from 6 Gbps to 3 Gbps is normal and expected. This has been documented; the following is from page 109 of the SMU Reference Guide

 

тАЬTransfer Rate. The data transfer rate in Gbit per second.


Some 6-Gbps disks might not consistently support a 6-Gbps transfer rate. If this happens, the P2000 controller automatically adjusts transfers to those disks to 3 Gbps, increasing reliability and reducing error messages with little impact on system performance. This rate adjustment persists until the controller is restarted or power-cycled.тАЭ

 

HP P2000 G3 MSA System SMU Reference Guide :http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02520791/c02520791.pdf
Part number: 500911-008
First edition: February 2013

Was your question answered correctly? If so, please remember to mark your question Answered when you get the correct answer and award KUDOS! to the person providing the answer. This helps others searching for a similar issue.
rocru
Occasional Contributor

Re: One SAS drive reporting lower transfer rate

Thanks AnkitM

AnkitM
Trusted Contributor

Re: One SAS drive reporting lower transfer rate

You're welcome.

If the information provided has answered your query or was helpful. Please click the KUDOS! star in the left column! :)
Was your question answered correctly? If so, please remember to mark your question Answered when you get the correct answer and award KUDOS! to the person providing the answer. This helps others searching for a similar issue.