ZFS and disk naming change (ex. da0->da4)

[Attila Nagy]

On 10/25/07 19:20, Pawel Jakub Dawidek wrote:
> On Thu, Oct 25, 2007 at 06:48:05PM +0200, Attila Nagy wrote:
>   
>> On 10/25/07 17:10, Pawel Jakub Dawidek wrote:
>>     
>>>> panic: kmem_malloc(131072): kmem_map too small: 335319040 total allocated
>>>> cpuid = 0
>>>> Uptime: 18m22s
>>>> Physical memory: 1015 MB
>>>> Dumping 372 MB: 357 341 325 309 293 277 261 245 229 213 197 181 165 149 
>>>> 133 117 101 85 69 53 37 21 5
>>>>
>>>> #0  doadump () at pcpu.h:195
>>>> 195             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
>>>>
>>>> I've tried to lower vfs.zfs.arc_max first to 32, then 16 MB, but the 
>>>> panics still occur.
>>>>    
>>>>         
>>> Have you tried the patch I posted some weeks ago?
>>>
>>> 	http://people.freebsd.org/~pjd/patches/vm_kern.c.2.patch
>>>  
>>>       
>> Umm, no, not until now.
>>
>> The result is the same:
>> Unread portion of the kernel message buffer:
>> panic: kmem_malloc(131072): kmem_map too small: 335331328 total allocated
>> cpuid = 0
>> Uptime: 15m25s
>> Physical memory: 1015 MB
>> Dumping 371 MB: 356 340 324 308 292 276 260 244 228 212 196 180 164 148 
>> 132 116 100 84 68 52 36 20 4
>>
>> #0  doadump () at pcpu.h:195
>> 195             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
>>
>> This is with the default settings, so:
>> vm.kmem_size_max: 335544320
>> vm.kmem_size: 335544320
>>     
>
> One more thing. Can you add:
>
> vm.kmem_size=629145600
> vm.kmem_size_max=629145600
>
> to your /boot/loader.conf, but don't touch any other settings (ie. don't
> tune maximum number of vnodes, ARC size, etc.), let ZFS to autotune
> them.
>   
Of course this works (it had been worked before the patch too, but to be 
honest, I did not try just upping the kmem_size alone, I did lower 
arc_max too).
The problem here is that if I install FreeBSD on such a machine and 
start using ZFS, I will get unexpected lockups and restarts.
I cannot reproduce this with UFS with the default settings.

Will there be a recommended loader.conf entry in the ZFS manual for 
lower memory machines, or is it possible to solve this, so no panic 
would occur even with the default values?

Thanks,

-- 
Attila Nagy                                   e-mail: Attila.Nagy at fsn.hu
Free Software Network (FSN.HU)                 phone: +3630 306 6758
http://www.fsn.hu/