Is there any way to increase the KVM?

Ivan Voras ivoras at
Sat Jun 7 10:03:47 UTC 2008

Pawel Jakub Dawidek wrote:
> On Thu, Jun 05, 2008 at 04:00:13PM +0200, Ivan Voras wrote:

>> At the risk of sounding repetitive, can you try a simple test on your
>> ZFS pools, to see if you can panic the kernel? Do this:
>> * install blogbench and bonnie++ from ports/benchmarks
>> * run:
>> 	blogbench -c 100 -d . -i 30 -r 50 -W 10 -w 10
>> 	bonnie++ -d . -s 16G -n 80
>>   in parallel, until completion or crash. It shouldn't take too long to
>> complete the above benchmarks, so you probably won't invest too much
>> time in it even if it doesn't crash.
> Both completed successfully (i386, 1GB of RAM, dual core CPU).


> Can you now go and revert all the FUD you spread? You probably need to
> invest much more time than that.

Right, I'm just an evil guy trying to badmouth the system that's a large 
chunk of my bread and butter because I'm bored. :) What should I say, 
"sorry for posting bug reports?" and "sorry for writing docs on which 
features of (current) ZFS to avoid to sidestep crashes?"

Actually I have a suspicion it's the second one (in ZFS wiki pages) 
you'd like cleared up, but keep in mind you were off the lists for a 
time and you are the principal source of information on our ZFS 
implementation. At the time there was a lot of incorrect information 
floating about in the mailing lists, where people (me included) were 
doing voodoo computing - trying every knob there was to see if it made a 
difference - and I tried to document whatever seemed to work to avoid 
answering repetitive questions posted on the lists.

I will be among the first to try the new patches (depending on the time 
zone, probably, and we're pretty close there) and, unfortunately, I will 
complain and ask guidance if things don't work. On the other hand, if 
they do work, I'll a) add big honking banners with bells and whistles 
proclaiming that it finally works in (HEAD | RELENG_7), optionally 
praising you to heaven for bringing it to completion[*], and b) buy you 
a BIGNUM of beers next time we meet.

[*] really, no sarcasm intended. It *was* an enormous job and if it 
works, you'd earn it! In the time I spent trying to make it work I saw 
from first-hand experience how great the whole idea of ZFS is and how 
useful it is in daily operation.

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