panic: kmem_malloc; Should I increase some setting?

Ronald Klop ronald-freebsd7 at
Tue Jun 29 18:36:24 PDT 2004

On Tue, 29 Jun 2004 18:22:57 -0700 (PDT), Doug White  
<dwhite at> wrote:

> On Wed, 30 Jun 2004, Ronald Klop wrote:
>> I get the following panics while untarring a 30MB archive on an md  
>> device
>> create with:
>> tmpmfs="YES"
>> tmpsize="256m"
> This is a malloc-backed md disk, which consumes memory directly from KVM.
> If you do a large extraction it will consume all of KVM and cause your
> panic.  Unless you're running diskless and this is your only option
> besides NFS, either don't use tmpmfs or avoid extracting large amounts of
> data to /tmp.

Thanks, I read this a few moments ago in the manual page.
Isn't there a way to prevent or warn people when they create a malloc  
backed disk that is larger than KVM? I think a panic isn't very user  
friendly and it took me quite some time to figure this out.


  Ronald Klop
  Amsterdam, The Netherlands

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