Peter Boy wrote:
> Am Mittwoch, den 11.06.2008, 13:30 +0200 schrieb Klaus Steinberger:
>>> I heard that downloading BT file hurts hard disk very much.  However,
>>> Case 1 and Case 2 do not have any relationship with BT task.
>>>
>>> Any technique or trick to avoid this?
>> That sounds like a major hardware problem.
> 
> Not necessarily, similiar problems here. When we tried to install a 5.1
> system with the Intel fake raid, the raid of the installed system didn't
> work because of identical LVM ids. In 5.0 we didn't encounter that
> problem, but the RAID became inconsistent after a while. Unfortunateley
> I couldn't spend the time to explore the prob extensively but switched
> to a true hardware raid (3-ware). On that system we sometimes encounter
> problemes with the home partition (ext3) which is no longer usable. We
> had to make  a new filesystem and replay the backup. (Un-)fortunately
> the problem is not reproducible on a regular base. "Most times" it
> works. I'm not shure if it is due to the regular file system or the Xen
> virtualisation layer. We are still exploring the details.
> 
In your case of 3ware raid card, it could be the Xen-kernel doesn't play
well with the 3ware raid driver!  5.1 uses the Redhat ported kernel
2.6.18-53.1.21.el5xen, which may not support the latest 3ware Raid card.

We purchased a system with 3ware Inc 9650SE SATA-II RAID (rev 01), this
card, for example, is not supported by the stock 2.6.18 kernel which is
still the official XenSource supported kernel.  While distributors will
port XenSource patches into their customized kernel, however, such
kernel might have stability problems.  In my case, the Ubuntu ported
Xen-kernel (2.6.24) would crash the 3Ware Raid under heavy IO (bonnie++
test) or corrupt file system after a few days, I finally found a stable
solution for our server, Ubuntu Gutsy + Fedora 8 Xen Kernel Source
compiled myself for the Ubuntu system.  Therefore, I would suspect that
the kernel Raid driver for RHEL 2.6.18 doesn't play with your particular
3Ware raid card.


-- 
Zhi-Wei Lu
Institute for Data Analysis and Visualization
University of California, Davis
(530) 752-0494