Johny Mail list wrote:

2007/7/3, Tejun Heo [off-list ref]:

quoted

Brad Campbell wrote:

quoted

Johny Mail list wrote:

quoted

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)

quoted

quoted

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.

How hard is it frozen?  Can you blink the Numlock LED?

I believe he said it was ICH5 (different post/thread).

My observation on ICH5 is that if one unplugs a drive,
then the chipset/cpu locks up hard when toggling SRST
in the EH code.

Specifically, it locks up at the instruction
which restores SRST back to the non-asserted state,
which likely corresponds to the chipset finally actually
sending a FIS to the drive.

A hard(ware) lockup, not software.
That's why Intel says ICH5 doesn't do hotplug.

Cheers