# SCSI sense: UNIT ATTENTION, a problem?



## giannidoe (Mar 16, 2011)

I've got an LSI Logic SAS3081e controller with 5 disks attached as JBOD and recently I've noticed these messages cropping up in the logs.


```
Mar 16 03:04:54 leiter kernel: (da3:mpt0:0:3:0): READ(10). CDB: 28 0 4 ad 5b a2 0 0 80 0 
Mar 16 03:04:54 leiter kernel: (da3:mpt0:0:3:0): CAM status: SCSI Status Error
Mar 16 03:04:54 leiter kernel: (da3:mpt0:0:3:0): SCSI status: Check Condition
Mar 16 03:04:54 leiter kernel: (da3:mpt0:0:3:0): SCSI sense: UNIT ATTENTION asc:29,0 (Power on, reset, or bus device reset occurred)
Mar 16 03:04:54 leiter kernel: (da5:mpt0:0:5:0): READ(10). CDB: 28 0 4 ad 5b a2 0 0 80 0 
Mar 16 03:04:54 leiter kernel: (da5:mpt0:0:5:0): CAM status: SCSI Status Error
Mar 16 03:04:54 leiter kernel: (da5:mpt0:0:5:0): SCSI status: Check Condition
Mar 16 03:04:54 leiter kernel: (da5:mpt0:0:5:0): SCSI sense: UNIT ATTENTION asc:29,0 (Power on, reset, or bus device reset occurred)
Mar 16 03:04:58 leiter kernel: (da4:mpt0:0:4:0): READ(10). CDB: 28 0 2 f6 96 a2 0 0 80 0 
Mar 16 03:04:58 leiter kernel: (da4:mpt0:0:4:0): CAM status: SCSI Status Error
Mar 16 03:04:58 leiter kernel: (da4:mpt0:0:4:0): SCSI status: Check Condition
Mar 16 03:04:58 leiter kernel: (da4:mpt0:0:4:0): SCSI sense: UNIT ATTENTION asc:29,0 (Power on, reset, or bus device reset occurred)
```

The SMART status of the disks is all fine, what are the likely causes of these messages and do I need to be concerned?


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## SirDice (Mar 16, 2011)

I'd check the most obvious first, see if all the cables are still properly seated. Also make sure you don't have a power problem.


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## giannidoe (Mar 16, 2011)

Cables all seem fine, they are SAS->4xSATA with clips.
No other components seem to be complaining, any suggestions for checking if it's a power issue?


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## tajudd (Mar 28, 2011)

giannidoe said:
			
		

> I've got an LSI Logic SAS3081e controller with 5 disks attached as JBOD and recently I've noticed these messages cropping up in the logs.
> 
> 
> ```
> ...



from mpt(4),


> The following controllers are supported by the mpt driver:
> 
> 
> ```
> ...



Is your controller one of the listed supported cards?  Is the RAID BIOS updated?  A supported card also would help if the BIOS/Firmware is up to the latest too.

The ASC 29/0 is not a common one I've seen, and I support mass disk storage subsystems at work.  I see tons of Sense Keys and ASC numbers and 29/0 is uncommon.

Therefore, I am gearing toward checking for compat hardware.


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## giannidoe (Mar 29, 2011)

It is supported, the chipset is 1068E.

I've now updated the firmware to the latest so I'll see how I get on.


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