[Lustre-devel] Re: Lustre echo question

Scott Atchley
2006-08-29T07:25:47Z

On Aug 29, 2006, at 9:13 AM, Eric Barton wrote:

> Scott,
>
>> Please let me know if you are still not back full time. If so, I can
>> post this to the devel list.
>
> yes; I''m back :)

Glad to hear it.

>> We are working on cleaning up MX on client reconnect (so MXLND can
>> cancel outstanding txs and rxs). At the same time, we are merging our
>> MX-2G and MX-10G code branches and we may have introduced a bug in MX
>> that I am seeing in MXLND. I am using your ltest scripts and I have
>> not seen these messages before:
>>
>> Aug 29 07:58:59 172.31.164.34 kernel: LustreError: 5642:0:(debug.c:
>> 167:block_debug_check()) echo: id 0x3 offset 556720128 end off:
>> 0x212de000 != 0x212ee000
>> Aug 29 07:58:59 172.31.164.34 kernel: LustreError: 5642:0:(debug.c:
>> 155:block_debug_check()) echo: id 0x3 offset 556724224 off:
>> 0x212df000 != 0x212ef000
>>
>> I assume that LNET is checking the bulk read and writes to ensure the
>> correct data was transfered. What is it checking specifically?
>
> yes indeed.  Both client and server do checks on a few locations at
> the
> start and end of each page of bulk data.  Look for block_debug_setup
> () and
> block_debug_check(), and where obdecho and echo_client call them to
> set/check the object number and file offset in each block (page) of
> bulk
> I/O.  It looks like data for the previous block got into this one.
>
>                 Cheers,
>                         Eric

That''s what I was afraid of. I am looking through the debug code now
and I added more information to the block to help us identify the
problem.

Thanks,

Scott