Weblog » 2008 » February

One thing I like about Linux and other pieces of open source software is error reporting.

Recently my console has been displaying the following errors at startup:


ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
ata1.00: cmd ef/05:fe:00:00:00/00:00:00:00:00/40 tag 0 cdb 0x0 data 0
res 51/04:fe:00:00:00/00:00:00:00:00/40 Emask 0x1 (device error)
ata1.00: configured for UDMA/133
ata1: EH complete


This is gibberish to most everyone, and it doesn’t cause a problem, so I ignored it until I got bored today.

I clearly have a ton of information here… I just have no idea what it means. So, being pedantic, I went to the source: the ATA Command Set

Command x’EF’ is “Set Features”
SubCommand x’05′ is “Enable Advanced Power Management”
Setting x’FE’ is “Full Performance”

So it looks like my system is trying to set my hard drive in high performance mode. And from the return codes, my hard drive doesn’t like being told what to do.

I’m still not sure what part of the OS caused these messages to start appearing, but now I’ve got a good idea where to check. This obnoxious power-save daemon has acted up before. I guess it is time to finally get it configured properly.

This post is for anyone else getting this error who isn’t anal-retentive enough to go look up the ATA specification.