Re: disappointing upgrade to NetBSD 5.0

["Dan Engholm" <mustang%engholm.org@localhost>]

On Tue, 26 May 2009 05:40:04 -0700, Jean-Yves Migeon  
<jeanyves.migeon%free.fr@localhost> wrote:

> Dan Engholm wrote:
> > I can't be sure what I am doing to get the problem to occur, but it  
> > seems
> > to be network related.  Looking around Google, I found one thread in
> > port-xen with a similar description but it dead ended with no  
> > resolution. (see  
> > http://mail-index.netbsd.org/port-xen/2009/01/18/msg004686.html)
>
> It is network related, but the error is due to the hypervisor returning  
> an error for the decrease memory operation. As the domU does not expect  
> it to fail, it ends in panic().
>
> Advice would be the same as in the link above: any error reported by the  
> hypervisor on its console?

The console doesn't show anything when the panic occurs.  I don't have a  
terminal on the serial port but my xconsole shows XEN related messages so  
I'm assuming that is where I would see something related to this problem,  
too.  Here is what I see while the user domain is starting up:

xvif2.0: Ethernet address aa:00:00:51:02:f0
May 26 18:39:11 xxxxxx routed[227]: Send bcast sendto(xvif2.0,  
172.16.3.7.520): Network is down
xbd backend: attach device wd1b (size 2097152) for domain 2
xbd backend: attach device raid2f (size 209715200) for domain 2
xbd backend: attach device raid1f (size 4194304) for domain 2
xvif2.0 using event channel 17
xbd backend 0 for domain 2 using event channel 18

> > Building databases:panic: buf mem pool index 7
> > Begin traceback...
> > uvm_fault(0xc9d58b98, 0, 1) -> 0xe
> > fatal page fault in supervisor mode
> > trap type 6 code 0 eip c0396531 cs 9 eflags 10246 cr2 0 ilevel 0
> > panic: trap
> > Faulted in mid-traceback; aborting...
> > dumping to dev 142,16 offset 1582223
> > dump device bad
> >  rebooting...
> >  What it should have said after "Building databases:" is:
> >  Building databases: dev, utmp, utmpx done
> > Starting syslogd.
> > Setting date via ntp.
> > Checking for core dump...
>
> Any chance we could get a backtrace?
>
> For that, edit the /etc/sysctl.conf of domU, set the ddb.onpanic to 1.  
> Then "bt" from ddb prompt.

panic: Unable to reduce memory reservation

fatal breakpoint trap in supervisor mode
trap type 1 code 0 eip c039504c cs 9 eflags 246 cr2 0 ilevel 4
Stopped in pid 579.1 (Xvnc) at  netbsd:breakpoint+0x4:  popl    %ebp
db> BT
No such command: BT
db> bt
breakpoint(c044097b,cb5cdae8,c0455bc0,c03a0011,ca217000,c049f440,cb5cdb1c,c049f440,1,2)  
at netbsd:breakpoint+0x4
panic(c04431b4,5108,5a8,c03a905a,c9d3e6ca,cb5cdc7c,cb371280,c02e3a06,caa4d043,bfbfe30d)  
at netbsd:panic+0x1a6
xen_network_handler(0,0,cb5cdb4c,c02ccedb,4,caa3b000,caa4d000,c0b96600,c03b0400,c0b8aa2c)  
at netbsd:xen_network_handler
xennet_rx_mbuf_free(c0b96600,caa4d000,4c,ca217f10,50435051,0,cb5cdb7c,13a8fa7,c0b96600,c0b8aae4)  
at netbsd:xennet_rx_mbuf_free+0x44
m_ext_free(c0b96600,0,cb5cdc7c,0,0,cb53e2c0,3,9,5cdbd4,cb53e2c0) at  
netbsd:m_ext_free+0x8b
soreceive(c0b8aa2c,0,cb5cdc7c,0,0,0,cb5cdcac,c0308303,cb5fed10,cb5fed10)  
at netbsd:soreceive+0xbc4
soo_read(cb5fed10,cb5fed10,cb5cdc7c,cb570528,1,cb5cdce0,c0102cf5,cb5cdc74,6,c9d40011)  
at netbsd:soo_read+0x34
dofileread(9,cb5fed10,bfbfe30d,9,cb5fed10,1,cb5cdd28,0,cb53e2c0,0) at  
netbsd:dofileread+0x73
sys_read(cb53e2c0,cb5cdd00,cb5cdd28,200203,1,fffffffe,0,9,bfbfe30d,9) at  
netbsd:sys_read+0x6f
syscall(cb5cdd48,cf001f,bfbf001f,816001f,bfbf001f,bfbfe824,9,bfbfe1d8,9,9)  
at netbsd:syscall+0xc7
db>

> > Since the upgrade, my user domain no longer boots without  
> > intervention.  It
> > does not figure out on its own where the root partition is so I have to
> > manually enter "xbd0a" from the Xen console.  The configuration file has
> > 'root = "/dev/xbd0a"' in it as it has since I started using Xen.  This  
> > is
> > true regardless of which version of Xen I use.
>
> And with root = "xbd0" ?

Specifying 'root = "xbd0a"' seemed to fix this problem.  Thanks.

> > Also, I got burned by Xen telling me that the "nics" configuration  
> > option
> > is obsolete.  The man page says that it's still valid and that its  
> > default
> > value is 1.  If I don't have a "nics = 1" line in my configuration  
> > file, no
> > NICs are created and the creation fails because it can't configure the
> > network.  What gives?
>
> vif array?
>
> vif = ['mac=00:16:3e:00:00:11, bridge=bridge0'] # for example

I don't get this one.  I could not create the user domain until I put  
'nics = 1' in but now I have it commented out and it works just fine.   
*sigh*

The saga continues.  See my follow-up to the other reply.

--Dan