[Lustre-discuss] Problems & partial success on PPC64 (XServe G5) Debian cluster

[Andreas Dilger]

On Nov 21, 2007  16:37 -0600, Robert Olson wrote:
> On Nov 21, 2007, at 4:30 PM, Andreas Dilger wrote:
>> On Nov 19, 2007  13:25 -0600, Robert Olson wrote:
>>> OK, early indications are good here. Started out with  MDT on PPC with 
>>> OST
>>> on intel, ran iozone up to 1M files and it finished without error and 
>>> with
>>> reasonable performance.
>>
>> Can you please run "e2fsck -fn" (from a Lustre-patched e2fsprogs) on the
>> filesystems after your tests.
>
> What will that tell me?

It will tell me if some endian bug is corrupting your ext3 filesystem
(and possibly if there are endian bugs in our e2fsprogs patches)...

>> The extents,mballoc options are primarily aimed at improving the 
>> performance
>> under high load by reducing CPU usage and getting better allocation.  if
>> you have mostly small files then the performance difference won't be huge.
>
> is this one of the changes that improves write performance? I've notice 
> write performance lagging reads.

Yes, mballoc+extents does improve write performance.  You could do a test
on the x86_64 system to compare the difference.

Cheers, Andreas
--
Andreas Dilger
Sr. Software Engineer, Lustre Group
Sun Microsystems of Canada, Inc.