Re: Linux Software RAID is really RAID?

[Brad Campbell <brad@wasp.net.au>]

Johny Mail list wrote:
> Hello list,
> I have a little question about software RAID on Linux.
> I have installed Software Raid on all my SC1425 servers DELL by
> believing that the md raid was a strong driver.
> And recently i make some test on a server and try to view if the RAID
> hard drive power failure work fine, so i power up my server and after
> booting and the prompt appear I disconnected the power cable of my
> SATA hard drive. Normaly the MD should eleminate the failure hard
> drive of the logical drive it build, and the server continue to work
> fine like nothing happen. Oddly the server stop to respond and i get
> this messages :
> ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
> ata4.00: cmd e7/00:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0
>              res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
> ata4: port is slow to respond, please be patient (Status 0xd0)
> ata4: port failed to respond (30sec, Status 0xd0)
> ata4: soft resetting port
> 
> After that my system is frozen. Normaly in a basic RAID the device is
> "disable" in the logical RAID device (md0) and it only use the last
> disk.

cc to linux-ide added.

Unfortunately this is not an artifact of the linux raid driver, rather it appears to be an issue 
with the SATA driver and related error recovery. Some information about what kernel, configuration, 
drives, controller cards and other relevant system information would be good.

See the information at this URL for the sort of extra information that would be handy.

http://www.kernel.org/pub/linux/docs/lkml/reporting-bugs.html


Regards,
Brad
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