[DRBD-user] DRBD serious locking due to TOE - UPDATE

Ben Clewett ben at roadrunner.uk.com
Mon Jan 7 13:39:34 CET 2008

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.



Hi Lars,

I completely understand, sorry for the missunderstanding.

I obviously thought your comment 'it lies to the kernel about having 
written stuff to disk' meant that it confuses DRBD.  Thanks for the 
clarification.

In which case my problem of DRBD locking is still outstanding.

Although Jure Pečar just emailed me to say he have found a problem with 
the latest bnx2 driver:

"Turns out I can also reproduce the problem with 1.6.7b driver. Now I'm 
in direct contact with Michael Chan, author of bnx2 driver. Let's see 
what he has to tell about this."

This may be the problem that so many users of this Broadcom network card 
are experiencing.  In which case we can all hope a solution is on the way...

Regards,

Ben

Lars Ellenberg wrote:
> On Mon, Jan 07, 2008 at 08:56:56AM +0000, Ben Clewett wrote:
>>
>> Hi Carson,
>>
>> Thanks for your reply.  It is certainly odd that a write-ahead-cache 
>> should make DRBD slower rather than faster.
> 
> you definetely misunderstood something here.
> 
>> The comments I picked up were from Lars Ellenberg:
>>
>> http://thread.gmane.org/gmane.linux.network.drbd/11397/focus=11401
>>
>> "no. more concern about your write cache in the cciss controller,
>> and whether it lies to the kernel about having written stuff to disk
>> when in fact it is only in that (probably not battery backed?) write
>> cache..."
> 
> my concerns here are about data reliability,
> and have nothing to do with anything "locking" or not.
> 
> this comment was meant to say:
> if you use write-back (aka write-behin, aka write-ahead) caches,
> then they better be persistent (aka "battery backed").
> 
> nothing more, nothing less.
> 
> 


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