[linux-lvm] more info on the hang with 2.6.15-rc5

[Old Fart]

Sebastian Kuzminsky wrote:
> Now it works, but I dont trust it one bit.
>
> I had been seeing almost immediate, perfectly repeatable hard lockups
> in 2.6.15-rc5 and 2.6.15-rc5-mm3, when using sata_mv, RAID, and LVM
> together.  Nothing in the syslog or on the console, and the system is
> totally unresponsive to the keyboard & network.
>
> My hardware setup is: four Seagate Barracuda 500 GB disks, on a Marvell
> MV88SX6081 8-port SATA-II PCI-X controller, on a PCI-X bus (64/66).
>
> The disks work great when accessed directly.  They work great when used
> as four PVs for LVM, and when assembled into a 4-disk RAID-6.
>
> But when I make a RAID-6 array out of them, and use the array as a PV,
> the system would hang completely, within seconds.  (This is with LVM
> 2.02.01, libdevicemapper 1.02.02, and dm-driver 4.5.0.)
>
> I turned on all the debugging options in the kernel config hoping to get
> some insight, but this "debug" kernel doesnt crash.  It's running fine,
> and I'm pounding on it.  A timing problem in the interaction between
> LVM and RAID?  Some kind of wierd heisenbug....
>
>
> I'd be happy to do any debugging tests people suggest.
>
>
>   
This won't be much help, but, there are some indications of a kernel 
problem with raid.  The problems may be fedora specific, but, currently 
fedora rawhide is following the upstream kernel.  See: 
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=176179

good luck.

-- 
Regards,

Old Fart