user-mode-linux-user

Re: [uml-user] umlslackroot (based on zipslack) root fs available!

[Henrique M. <web...@pl...>]

New link, sorry for inconvenience!

http://www.playreef.com/my_uml/pool_h01/

[uml-user] cannot bring up the serial line

[Han <kee...@gm...>]

Hi,

I am following the instruction in the User Mode Linux book (Jeff Dike) and
trying to bring up its serial line. But not working so far.

What I did was:

1.  edit the /etc/inittab file and enabled this line:

T0:2345:respawn:/sbin/getty -L ttyS0 9600 vt100

2.  added command line option when booting UML:

ssl=pts

Once the UML boots,  I cannot find anything in 'dmesg' about the serial
line.  And I got following msg after a few minutes:

INIT: Id "T0" respawning too fast: disabled for 5 minutes

What did I miss?  I also tried the following line in inittab but still not
working:

S0:23:respawn:/sbin/agetty ttyS0 9600 vt100-nav


Any advices?

thanks
Han

Re: [uml-user] Configure UML to generate core file

[richard -r. w. <ric...@gm...>]

On Fri, Sep 13, 2013 at 7:33 AM, madhusudan r <mad...@ya...> wrote:
> Hi,
>
> The UML I run on Ubuntu crashes occasionally, but does not generate any core
> file. I'd like to know the necessary configuration to be applied on UML so
> it generates a core when it crashes. Also, additional configuration which
> will ease the process of analyzing the core would be appreciated.

Just set RLIMIT_CORE to a non-zero value.

-- 
Thanks,
//richard

[uml-user] Configure UML to generate core file

[madhusudan r <mad...@ya...>]

Hi,

The UML I run on Ubuntu crashes occasionally, but does not generate any core file. I'd like to know the necessary configuration to be applied on UML so it generates a core when it crashes. Also, additional configuration which will ease the process of analyzing the core would be appreciated.

Thanks,
Madhu

Re: [uml-user] tsc.c in UML

[Richard W. <ri...@no...>]

Am 27.08.2013 23:30, schrieb Han:
> 
> 
> 
> On Tue, Aug 27, 2013 at 2:28 PM, Han <kee...@gm... <mailto:kee...@gm...>> wrote:
> 
> 
> 
> 
>     On Tue, Aug 27, 2013 at 1:31 PM, Richard Weinberger <ri...@no... <mailto:ri...@no...>> wrote:
> 
>         Hi!
> 
>         Am 27.08.2013 19 <tel:27.08.2013%2019>:51, schrieb Han:
>         >
>         > On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <ric...@gm... <mailto:ric...@gm...> <mailto:ric...@gm...
>         <mailto:ric...@gm...>>> wrote:
>         >
>         >     On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm... <mailto:kee...@gm...> <mailto:kee...@gm... <mailto:kee...@gm...>>> wrote:
>         >     > Hi,
>         >     >
>         >     > I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
>         >     > "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
>         >     > available.
>         >     >
>         >     > My question is:  what's the reason that "tsc.c" not included in UML?  Is
>         >     > there any config or simple way(patch?)  to include it in UML?
>         >
>         >     Simply because UML has no TSC.
>         >
>         >
>         >
>         > [Han]  I don't really understand why UML has no TSC.   As I know,  TSC is accessible from user space process (on x86 at least) and I don't see any obvious reason why UML
>         does not
>         > support TSC.   I might missed something.
> 
>         What exactly is the problem you are trying to solve?
> 
>         > I am trying to add TSC into UML kernel (2.6.27)  for an experiment.   Is that a practical thing to do at all?
> 
>         What exactly do you want to add? TSC as a clocksource to UML..?
> 
> 
>     my immediate need is to compile and run an application that uses "cpu_khz"  (which is part of tsc.c).  I cannot modify the source code of the application as I am not the owner.  
> 
> [Han] sorry,  when I say "application",  I really meant Kernel Module. (klm). 

I really cannot help you on closed sources Kernel modules. You are on your own.
But you can look how arch/x86 computes cpu_khz. If you find a sane way to make it available on UML, fine. :)

Thanks,
//richard

Re: [uml-user] tsc.c in UML

[Han <kee...@gm...>]

On Tue, Aug 27, 2013 at 2:28 PM, Han <kee...@gm...> wrote:

>
>
>
> On Tue, Aug 27, 2013 at 1:31 PM, Richard Weinberger <ri...@no...>wrote:
>
>> Hi!
>>
>> Am 27.08.2013 19:51, schrieb Han:
>> >
>> > On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <
>> ric...@gm... <mailto:ric...@gm...>>
>> wrote:
>> >
>> >     On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm... <mailto:
>> kee...@gm...>> wrote:
>> >     > Hi,
>> >     >
>> >     > I am using Linux kernel 2.6.27 for building UML kernel.  It seems
>> like
>> >     > "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz"
>> is not
>> >     > available.
>> >     >
>> >     > My question is:  what's the reason that "tsc.c" not included in
>> UML?  Is
>> >     > there any config or simple way(patch?)  to include it in UML?
>> >
>> >     Simply because UML has no TSC.
>> >
>> >
>> >
>> > [Han]  I don't really understand why UML has no TSC.   As I know,  TSC
>> is accessible from user space process (on x86 at least) and I don't see any
>> obvious reason why UML does not
>> > support TSC.   I might missed something.
>>
>> What exactly is the problem you are trying to solve?
>>
>> > I am trying to add TSC into UML kernel (2.6.27)  for an experiment.
>> Is that a practical thing to do at all?
>>
>> What exactly do you want to add? TSC as a clocksource to UML..?
>>
>
> my immediate need is to compile and run an application that uses "cpu_khz"
>  (which is part of tsc.c).  I cannot modify the source code of the
> application as I am not the owner.
>
> [Han] sorry,  when I say "application",  I really meant Kernel Module.
(klm).

thanks.
Han

thanks.
> Han
>
>>
>> Thanks,
>> //richard
>>
>>
>

Re: [uml-user] tsc.c in UML

[Han <kee...@gm...>]

On Tue, Aug 27, 2013 at 1:31 PM, Richard Weinberger <ri...@no...> wrote:

> Hi!
>
> Am 27.08.2013 19:51, schrieb Han:
> >
> > On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <
> ric...@gm... <mailto:ric...@gm...>> wrote:
> >
> >     On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm... <mailto:
> kee...@gm...>> wrote:
> >     > Hi,
> >     >
> >     > I am using Linux kernel 2.6.27 for building UML kernel.  It seems
> like
> >     > "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz"
> is not
> >     > available.
> >     >
> >     > My question is:  what's the reason that "tsc.c" not included in
> UML?  Is
> >     > there any config or simple way(patch?)  to include it in UML?
> >
> >     Simply because UML has no TSC.
> >
> >
> >
> > [Han]  I don't really understand why UML has no TSC.   As I know,  TSC
> is accessible from user space process (on x86 at least) and I don't see any
> obvious reason why UML does not
> > support TSC.   I might missed something.
>
> What exactly is the problem you are trying to solve?
>
> > I am trying to add TSC into UML kernel (2.6.27)  for an experiment.   Is
> that a practical thing to do at all?
>
> What exactly do you want to add? TSC as a clocksource to UML..?
>

my immediate need is to compile and run an application that uses "cpu_khz"
 (which is part of tsc.c).  I cannot modify the source code of the
application as I am not the owner.

thanks.
Han

>
> Thanks,
> //richard
>
>

Re: [uml-user] tsc.c in UML

[Richard W. <ri...@no...>]

Hi!

Am 27.08.2013 19:51, schrieb Han:
> 
> On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <ric...@gm... <mailto:ric...@gm...>> wrote:
> 
>     On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm... <mailto:kee...@gm...>> wrote:
>     > Hi,
>     >
>     > I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
>     > "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
>     > available.
>     >
>     > My question is:  what's the reason that "tsc.c" not included in UML?  Is
>     > there any config or simple way(patch?)  to include it in UML?
> 
>     Simply because UML has no TSC.
> 
> 
> 
> [Han]  I don't really understand why UML has no TSC.   As I know,  TSC is accessible from user space process (on x86 at least) and I don't see any obvious reason why UML does not
> support TSC.   I might missed something.  

What exactly is the problem you are trying to solve?

> I am trying to add TSC into UML kernel (2.6.27)  for an experiment.   Is that a practical thing to do at all? 

What exactly do you want to add? TSC as a clocksource to UML..?

Thanks,
//richard

Re: [uml-user] tsc.c in UML

[Han <kee...@gm...>]

On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <
ric...@gm...> wrote:

> On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm...> wrote:
> > Hi,
> >
> > I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
> > "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
> > available.
> >
> > My question is:  what's the reason that "tsc.c" not included in UML?  Is
> > there any config or simple way(patch?)  to include it in UML?
>
> Simply because UML has no TSC.
>


[Han]  I don't really understand why UML has no TSC.   As I know,  TSC is
accessible from user space process (on x86 at least) and I don't see any
obvious reason why UML does not support TSC.   I might missed something.

I am trying to add TSC into UML kernel (2.6.27)  for an experiment.   Is
that a practical thing to do at all?

thanks
Han


> > I have not tried the same on the newer kernels yet as my target system
> uses
> > 2.6.27 only so I prefer to stick with 2.6.27 if possible.
> >
> > thanks
> > Han
> >
> >
> >
> ------------------------------------------------------------------------------
> > Introducing Performance Central, a new site from SourceForge and
> > AppDynamics. Performance Central is your source for news, insights,
> > analysis and resources for efficient Application Performance Management.
> > Visit us today!
> >
> http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk
> > _______________________________________________
> > User-mode-linux-user mailing list
> > Use...@li...
> > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
> >
>
>
>
> --
> Thanks,
> //richard
>

Re: [uml-user] UML+Mounting host fs + chroot in the mounted host drive

[Teto <mat...@gm...>]

Wow that's a great answer. Thank you to have taken the time to detail
thing. It's a lot clearer now.


> 1) You point (via umlsetup.sh) at the kernel source you want, it makes an lndir
> link tree (%1) for the kernel, and compiles it.
I use the "O=<output directory>" switch to compile for different
architectures. You can then set different directories for binaries and
.config files. True you cannot patch as you want though.
I did not know "lndir", reminded me of a character in the lord of the
rings : http://lotr.wikia.com/wiki/E%C3%A4rendil ^^

> 2) You also point at the UML root tree you want to use.
> That's an extracted file system that lives on the host, not a COW or loopback
> file.  We suggest you put your UML file systems on the same disk as
> your reference root file system, as it can use hard links, which is way
> faster, and saves piles of disk space.
This is my main interrogation. Why going through the trouble of
creating a specific filesystem when there is already one working in
the host ? I would like in my init to "UML$mount none /mnt/host -t
hostfs" than "UML$chroot /mnt/host" (just discovered the switch_root
utility in busybox). I can see problems with /proc and /dev colliding
between my initramfs and my host drive. So maybe I could mount all
other folders but those from my host "/" into the UML machine ?
On top of that I don't see any incentive (at least in my case) to
switch_root from the initramfs to a root filesystem ?! (maybe I could
embed everything I need in the initramfs)

> At some point, hostfs grew caching, which is annoying, because it means that
> I have to rm /my/test/program from within the UML, each time before I can
> make DESTDIR= install it again from the host, or the file does not update. I
> wish I could turn that off.
I guess you refer to CONFIG_CLEANCACHE and CONFIG_FRONTSWAP. I've just
enabled them in reaction to your warning.


> 02 - this sucks in some variables that tells net.A.sh, if there is a
>    uml_netjig  (a version of uml_switch that knows how to play back pcap
>    files), running, or if one should use multicast sockets.
This looks like a custom version. I think I wil rely on tun/tap sytems
for networking since I want my VMs to interact with Internet.

Btw, unstrung looks like a nice project.

Once more thanks for having been through the trouble of explaining all
this. It helps a lot.

Best regards
MAtt

Re: [uml-user] UML+Mounting host fs + chroot in the mounted host drive

[Michael R. <mc...@sa...>]

Teto <mat...@gm...> wrote:
    >> Yes, you could do this.  I use hostfs for /, and I just mount
    >> /usr/share from the host.

    > Could you please detail the procedure since I get lost in your files.

    > And the man page looks ambiguous to me.  First how do you launch your
    > uml kernel: just host$ ./uml_kernel initrd=custom_initrd or you add "
    > root=cowtempfile,/dev/sdb5" ?  I wish you could explain to me what to
    > mount and when. Your init replace the temporary (/,/dev,/etc etc..) by

High-level explanation of UNTI.
1) You point (via umlsetup.sh) at the kernel source you want, it makes an lndir
link tree (%1) for the kernel, and compiles it.

2) You also point at the UML root tree you want to use.
That's an extracted file system that lives on the host, not a COW or loopback
file.  We suggest you put your UML file systems on the same disk as
your reference root file system, as it can use hard links, which is way
faster, and saves piles of disk space.

3) an initrd is created from files in the root file system, and a linuxrc
   file is created that:
   a) populates a /dev (we used to use devfs, but it went away) into a ramfs.
   b) gropes /proc/cmdline to find out where / is on the host, and mounts it
      with hostfs.
   c) invokes /sbin/init

At some point, hostfs grew caching, which is annoying, because it means that
I have to rm /my/test/program from within the UML, each time before I can
make DESTDIR= install it again from the host, or the file does not update. I
wish I could turn that off.

(%1) since 2.6.x some other make options would let you avoid that, but
     in some cases one wants to patch the kernel before compiling, but
     not screw with the original kernel source, and anyway, we started
     in the 2.4 days.

LOW LEVEL stuff. A script is generated:

00 #!/bin/sh
01
02 if [ -z "${TEST_PURPOSE}" ] && [ -f /uml/umlbuild/.switches.sh ]; then . /uml/umlbuild/.switches.sh; fi
03 # get  value from baseconfig
04 . /corp/projects/pandora/unstrung/testing/baseconfigs/net.A.sh
05
06 /uml/umlbuild/plain/vmlinux initrd=/uml/umlbuild/initrd.cpio
   umlroot=/uml/umlbuild/A/root
   root=/dev/ram0 rw ssl=pty
   ssl0=port:1300 ssl1=port:1301
   umid=A $net
   $UML_DEBUG_OPT $UML_A_OPT
   rdinit=/linuxrc $*
07 if [ -n "$UML_SLEEP" ]; then eval $UML_SLEEP; fi

02 - this sucks in some variables that tells net.A.sh, if there is a
   uml_netjig  (a version of uml_switch that knows how to play back pcap
   files), running, or if one should use multicast sockets.
04 - each virtual machine has some network configuration, which looks like:

    net_eth0="eth0=mcast,12:00:00:dc:bc:ff,239.192.0.1,21200"
    net_eth1="eth1=mcast,12:00:00:64:64:23,239.192.1.2,31200";
    net="$net_eth0 $net_eth1"

06 - the kernel to run.
   - the initrd in CPIO format.
   - umlroot= path to what path on the host to mount as /
   - serial port 0 is the current pty, and some additional serial ports.
     I use serial ports with gdbattach a lot to let me debug a
     process inside the UML from outside.  If I'm debugging the kernel
     itself, I just gdb attach to the kernel.
   - $net from above.
   - rdinit=/linuxrc

07 - I tend to run the start.sh script in a fresh xterm -e, and if the kernel
   bails, the xterm closes immediately, so "export UMLSLEEP='sleep 60'" helps
   here.

https://github.com/mcr/unstrung uses this, as does:
https://github.com/xelerance/openswan

See https://github.com/mcr/unstrung/blob/master/testing/utils/linuxrc-uml.sh
for the linuxrc that I use.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [

Re: [uml-user] UML+Mounting host fs + chroot in the mounted host drive

[Teto <mat...@gm...>]

Thanks for your answer.

> I have been doing this since 2001 :-)
> I've tried to extract this system into a separate package, see:
> https://github.com/mcr/uml-network-testing-infrastructure
That's really cool to put these files online. Moreover I intend to use
UML for network testing as well so it's even better.

> Yes, you could do this.
> I use hostfs for /, and I just mount /usr/share from the host.
Could you please detail the procedure since I get lost in your files.
And the man page looks ambiguous to me.
First how do you launch your uml kernel: just  host$ ./uml_kernel
initrd=custom_initrd or you add " root=cowtempfile,/dev/sdb5" ?
I wish you could explain to me what to mount and when. Your init
replace the temporary (/,/dev,/etc etc..) by the host ? I don't really
understand the loop option exhibited in the documentation. The author
then say to change authorizations to the mounted folder but I am
afraid it will change all the authorizations on my host drive :s

Best regards
Matt


> --
> ]               Never tell me the odds!                 | ipv6 mesh networks [
> ]   Michael Richardson, Sandelman Software Works        | network architect  [
> ]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [
>

Re: [uml-user] UML+Mounting host fs + chroot in the mounted host drive

[Michael R. <mc...@sa...>]

Teto <mat...@gm...> wrote:
    > My current technique is to boot the kernel to test with a custom initrd
    > that mounts the host filesystem, chroot to this mounted directory so
    > that I can use my host binaries (custom ip route binaries already
    > installed in my host etc...). I've seen no thread presenting this
    > though it's very practical so I was wondering if that violated some
    > rules (could harm host system for instance ?) or is it because it's not
    > how UML is meant to be used (it aims at isolating).

I have been doing this since 2001 :-)
I've tried to extract this system into a separate package, see:
https://github.com/mcr/uml-network-testing-infrastructure
(I've decided to call this "UNTI". I hacked a bunch of on the weekend,
let me push from my laptop)

    > I wondered if I could use my host drive as a root filesystem
    > (read-only, using a qcow2 file to save changes) to boot UML instead of
    > creating/downloading a filesystem ?

Yes, you could do this.
I use hostfs for /, and I just mount /usr/share from the host.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [

[uml-user] UML+Mounting host fs + chroot in the mounted host drive

[Teto <mat...@gm...>]

Hi,

First a bit of context, I am looking for a kernel test & debug
platform. I hesitate between QEmu and UML for this but I like the
hostfs ability of UML (less complicated than 9p in qemu). As I run
those tests on different computers and synchronize things via git, I
prefer to do without a root filesystem/any binary.

My current technique is to boot the kernel to test with a custom
initrd that mounts the host filesystem, chroot to this mounted
directory so that I can use my host binaries (custom ip route
binaries already installed in my host etc...). I've seen no thread
presenting this though it's very practical so I was wondering if that
violated some rules (could harm host system for instance ?) or is it
because it's not how UML is meant to be used (it aims at isolating).

I wondered if I could use my host drive as a root filesystem
(read-only, using a qcow2 file to save changes) to boot UML instead of
creating/downloading a filesystem ?

Best regards
MAtt

Re: [uml-user] tsc.c in UML

[richard -r. w. <ric...@gm...>]

On Fri, Aug 23, 2013 at 8:35 PM, Han <kee...@gm...> wrote:
> Hi,
>
> I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
> "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
> available.
>
> My question is:  what's the reason that "tsc.c" not included in UML?  Is
> there any config or simple way(patch?)  to include it in UML?

Simply because UML has no TSC.

> I have not tried the same on the newer kernels yet as my target system uses
> 2.6.27 only so I prefer to stick with 2.6.27 if possible.
>
> thanks
> Han
>
>
> ------------------------------------------------------------------------------
> Introducing Performance Central, a new site from SourceForge and
> AppDynamics. Performance Central is your source for news, insights,
> analysis and resources for efficient Application Performance Management.
> Visit us today!
> http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk
> _______________________________________________
> User-mode-linux-user mailing list
> Use...@li...
> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>



-- 
Thanks,
//richard

[uml-user] tsc.c in UML

[Han <kee...@gm...>]

Hi,

I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
"arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
available.

My question is:  what's the reason that "tsc.c" not included in UML?  Is
there any config or simple way(patch?)  to include it in UML?

I have not tried the same on the newer kernels yet as my target system uses
2.6.27 only so I prefer to stick with 2.6.27 if possible.

thanks
Han

Re: [uml-user] how to build programs for running in UML

[Michael R. <mc...@sa...>]

Han <kee...@gm...> wrote:
    > [Han] in my case, the host is using a different linux kernel and different 32/
    > 64-bit-ness.  And I can't change that.  And I also cannot mount the UML rootfs
    > (don't have permission) to add things from the host.  

I see.

    > [Han]  I don't have the network connection from inside the UML yet. Need to set
    > up that first and try to install things.  

Then you will be unable to setup networking for the UML either.

Use qemu to mount/fix your fs: It has a reverse NAT network stack which does not
require root, but also doesn't really put your VM on the network.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [

Re: [uml-user] how to build programs for running in UML

[Han <kee...@gm...>]

I was able to manually install more packages after the "debootstrap"
created the basic rootfs. Now I have a much more complete rootfs and was
able to run the programs I compiled earlier on the host.

thanks for all your help.


On Thu, Aug 8, 2013 at 8:56 AM, Tony Su <to...@su...> wrote:

> If your rootfs is incomplete I've generally speculated it was designed to
> run on a similar Host and likely would need bind mounts.
>
> The following is where I get complete fs which can run independently on
> any Host
> Http://openvz.org/Download/template/precreated
>
> Although the fs are built for openvz  I've used them for UML, LXC.
>
> HTH
> Tony
> On Aug 7, 2013 11:10 AM, "Han" <kee...@gm...> wrote:
>
>>
>>
>> On Tue, Aug 6, 2013 at 7:51 PM, Michael Richardson <mc...@sa...>wrote:
>>
>>>
>>> Han <kee...@gm...> wrote:
>>>     > I am trying to build and run some of my C programs in UML.  One
>>> way I tried is
>>>     > to build (i.e. compile) the program on the host,  then run it in
>>> UML.  The
>>>     > problem is that the UML rootfs I used lacks many of the /usr/lib/
>>> shared
>>>     > libraries, hence the program failed to run.
>>>
>>> Well, you have to install the things you need then.
>>>
>>>     > My question is:  what is the best practice to build and run C
>>> programs for UML?
>>>     >  Do people normally compile the program on the host and then run
>>> it in UML?
>>>     > Or  compile the program directly in UML and then run it?
>>>
>>> I make sure I have the same operating system and 32/64-bit-ness, and I
>>> use
>>> hostfs, and I use "make DESTDIR=/path/to/my/uml/instance install".
>>>
>>
>> [Han] in my case, the host is using a different linux kernel and
>> different 32/64-bit-ness.  And I can't change that.  And I also cannot
>> mount the UML rootfs (don't have permission) to add things from the host.
>>
>> the linux machine I used to build the UML rootfs is different from the
>> linux host that I run the UML.
>>
>>
>>>
>>>     > If folks compile the C programs in UML directly,  where the "gcc"
>>> comes from?
>>>     >  Is it built part of the rootfs,  or some add-ons?  Any pointers
>>> for that?
>>>
>>> It's part of the rootfs, and you have a complete operating system there.
>>> You use yum or apt or yast2 to install whatever you need.
>>>
>>
>> [Han]  I don't have the network connection from inside the UML yet. Need
>> to set up that first and try to install things.
>>
>> thanks.
>>
>>
>>>
>>> --
>>> ]               Never tell me the odds!                 | ipv6 mesh
>>> networks [
>>> ]   Michael Richardson, Sandelman Software Works        | network
>>> architect  [
>>> ]     mc...@sa...  http://www.sandelman.ca/        |   ruby on
>>> rails    [
>>>
>>>
>>
>>
>> ------------------------------------------------------------------------------
>> Get 100% visibility into Java/.NET code with AppDynamics Lite!
>> It's a free troubleshooting tool designed for production.
>> Get down to code-level detail for bottlenecks, with <2% overhead.
>> Download for free and get started troubleshooting in minutes.
>>
>> http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
>> _______________________________________________
>> User-mode-linux-user mailing list
>> Use...@li...
>> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>>
>>

Re: [uml-user] how to build programs for running in UML

[Tony Su <to...@su...>]

If your rootfs is incomplete I've generally speculated it was designed to
run on a similar Host and likely would need bind mounts.

The following is where I get complete fs which can run independently on any
Host
Http://openvz.org/Download/template/precreated

Although the fs are built for openvz  I've used them for UML, LXC.

HTH
Tony
On Aug 7, 2013 11:10 AM, "Han" <kee...@gm...> wrote:

>
>
> On Tue, Aug 6, 2013 at 7:51 PM, Michael Richardson <mc...@sa...>wrote:
>
>>
>> Han <kee...@gm...> wrote:
>>     > I am trying to build and run some of my C programs in UML.  One way
>> I tried is
>>     > to build (i.e. compile) the program on the host,  then run it in
>> UML.  The
>>     > problem is that the UML rootfs I used lacks many of the /usr/lib/
>> shared
>>     > libraries, hence the program failed to run.
>>
>> Well, you have to install the things you need then.
>>
>>     > My question is:  what is the best practice to build and run C
>> programs for UML?
>>     >  Do people normally compile the program on the host and then run it
>> in UML?
>>     > Or  compile the program directly in UML and then run it?
>>
>> I make sure I have the same operating system and 32/64-bit-ness, and I use
>> hostfs, and I use "make DESTDIR=/path/to/my/uml/instance install".
>>
>
> [Han] in my case, the host is using a different linux kernel and different
> 32/64-bit-ness.  And I can't change that.  And I also cannot mount the UML
> rootfs (don't have permission) to add things from the host.
>
> the linux machine I used to build the UML rootfs is different from the
> linux host that I run the UML.
>
>
>>
>>     > If folks compile the C programs in UML directly,  where the "gcc"
>> comes from?
>>     >  Is it built part of the rootfs,  or some add-ons?  Any pointers
>> for that?
>>
>> It's part of the rootfs, and you have a complete operating system there.
>> You use yum or apt or yast2 to install whatever you need.
>>
>
> [Han]  I don't have the network connection from inside the UML yet. Need
> to set up that first and try to install things.
>
> thanks.
>
>
>>
>> --
>> ]               Never tell me the odds!                 | ipv6 mesh
>> networks [
>> ]   Michael Richardson, Sandelman Software Works        | network
>> architect  [
>> ]     mc...@sa...  http://www.sandelman.ca/        |   ruby on
>> rails    [
>>
>>
>
>
> ------------------------------------------------------------------------------
> Get 100% visibility into Java/.NET code with AppDynamics Lite!
> It's a free troubleshooting tool designed for production.
> Get down to code-level detail for bottlenecks, with <2% overhead.
> Download for free and get started troubleshooting in minutes.
> http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
> _______________________________________________
> User-mode-linux-user mailing list
> Use...@li...
> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>
>

Re: [uml-user] how to build programs for running in UML

[Han <kee...@gm...>]

On Tue, Aug 6, 2013 at 7:51 PM, Michael Richardson <mc...@sa...> wrote:

>
> Han <kee...@gm...> wrote:
>     > I am trying to build and run some of my C programs in UML.  One way
> I tried is
>     > to build (i.e. compile) the program on the host,  then run it in
> UML.  The
>     > problem is that the UML rootfs I used lacks many of the /usr/lib/
> shared
>     > libraries, hence the program failed to run.
>
> Well, you have to install the things you need then.
>
>     > My question is:  what is the best practice to build and run C
> programs for UML?
>     >  Do people normally compile the program on the host and then run it
> in UML?
>     > Or  compile the program directly in UML and then run it?
>
> I make sure I have the same operating system and 32/64-bit-ness, and I use
> hostfs, and I use "make DESTDIR=/path/to/my/uml/instance install".
>

[Han] in my case, the host is using a different linux kernel and different
32/64-bit-ness.  And I can't change that.  And I also cannot mount the UML
rootfs (don't have permission) to add things from the host.

the linux machine I used to build the UML rootfs is different from the
linux host that I run the UML.


>
>     > If folks compile the C programs in UML directly,  where the "gcc"
> comes from?
>     >  Is it built part of the rootfs,  or some add-ons?  Any pointers for
> that?
>
> It's part of the rootfs, and you have a complete operating system there.
> You use yum or apt or yast2 to install whatever you need.
>

[Han]  I don't have the network connection from inside the UML yet. Need to
set up that first and try to install things.

thanks.


>
> --
> ]               Never tell me the odds!                 | ipv6 mesh
> networks [
> ]   Michael Richardson, Sandelman Software Works        | network
> architect  [
> ]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails
>    [
>
>

Re: [uml-user] how to build programs for running in UML

[Michael R. <mc...@sa...>]

Han <kee...@gm...> wrote:
    > I am trying to build and run some of my C programs in UML.  One way I tried is
    > to build (i.e. compile) the program on the host,  then run it in UML.  The
    > problem is that the UML rootfs I used lacks many of the /usr/lib/ shared
    > libraries, hence the program failed to run.  

Well, you have to install the things you need then.

    > My question is:  what is the best practice to build and run C programs for UML?
    >  Do people normally compile the program on the host and then run it in UML?  
    > Or  compile the program directly in UML and then run it? 

I make sure I have the same operating system and 32/64-bit-ness, and I use
hostfs, and I use "make DESTDIR=/path/to/my/uml/instance install".

    > If folks compile the C programs in UML directly,  where the "gcc" comes from?
    >  Is it built part of the rootfs,  or some add-ons?  Any pointers for that?  

It's part of the rootfs, and you have a complete operating system there.
You use yum or apt or yast2 to install whatever you need.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [

[uml-user] how to build programs for running in UML

[Han <kee...@gm...>]

Hi,

I am trying to build and run some of my C programs in UML.  One way I tried
is to build (i.e. compile) the program on the host,  then run it in UML.
 The problem is that the UML rootfs I used lacks many of the /usr/lib/
shared libraries, hence the program failed to run.

My question is:  what is the best practice to build and run C programs for
UML?  Do people normally compile the program on the host and then run it in
UML?   Or  compile the program directly in UML and then run it?

If folks compile the C programs in UML directly,  where the "gcc" comes
from?  Is it built part of the rootfs,  or some add-ons?  Any pointers for
that?

(meantime, I am trying to load a rootfs that has gcc but had issues with
that.... )

Thanks.
Han

Re: [uml-user] self-built root filesystem failed to boot

[Han <kee...@gm...>]

thanks Steliosm.   I tried with "init=/bin/bash" but still same error.  It
seems that not anything wrong with "init" process itself, but some error
happened before that.

I just tried to build the rootfs without "--variant=buildd".  And this time
it worked.  Not sure what changed. Will play around more.

Han


On Tue, Aug 6, 2013 at 12:35 PM, Stelios M. <ste...@gm...> wrote:

> Hello.
>
> You could try to loop mount the root fs and check if there is an init
> there. You could also boot it with bash as init (init=/bin/bash) and check
> things.
>
> Regards,
> Steliosm
> On Aug 6, 2013 9:30 PM, "Han" <kee...@gm...> wrote:
>
>> Hi,
>>
>> I've built a root filesystem based off Debian Squeeze because I wanted to
>> include all built (e.g. gcc) tools in.  However,  i was not able to boot
>> the UML with this rootfs due to this error:
>>
>> <snip>
>> Kernel panic - not syncing: No init found.  Try passing init= option to
>> kernel.
>> </snip>
>>
>> here is how I ran the UML:
>>
>> ./linux ubda=/nobackup/hxu2/uml/debian-root-fs mem=128M
>>
>> I also tried to add "init=/sbin/init" or "init=3" at the end, but got the
>> same error.
>>
>> I believe I missed something when building the rootfs for the Init
>> option. But what is it?  How should I set the init option in the rootfs?
>>  please advise.
>>
>> thanks
>> Han
>>
>>
>>
>>
>> ------------------------------------------------------------------------------
>> Get 100% visibility into Java/.NET code with AppDynamics Lite!
>> It's a free troubleshooting tool designed for production.
>> Get down to code-level detail for bottlenecks, with <2% overhead.
>> Download for free and get started troubleshooting in minutes.
>>
>> http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
>> _______________________________________________
>> User-mode-linux-user mailing list
>> Use...@li...
>> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>>
>>

Re: [uml-user] self-built root filesystem failed to boot

[Michael R. <mc...@sa...>]

Han <kee...@gm...> wrote:
    > I've built a root filesystem based off Debian Squeeze because I wanted to
    > include all built (e.g. gcc) tools in.  However,  i was not able to boot the
    > UML with this rootfs due to this error:

    > <snip>
    > Kernel panic - not syncing: No init found.  Try passing init= option to kernel.
    > </snip>

    > here is how I ran the UML:

    > ./linux ubda=/nobackup/hxu2/uml/debian-root-fs mem=128M 

Did you include ext3 or whatever file system you built the image with?
What if you say, "root=/dev/ubda"?   While you can sometimes get away without
initramfs now, it's getting harder and harder.

I have broken off most of the Freeswan/Openswan UML build environment off
as a separate project at:
   https://github.com/mcr/uml-network-testing-infrastructure

This likely doesn't work with kernels newer than 2.6.26, but I do have fixes
in other trees for that, I just haven't moved things over.  If it is useful
to someone, I will spend the time.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mc...@sa...  http://www.sandelman.ca/        |   ruby on rails    [

Re: [uml-user] self-built root filesystem failed to boot

[Stelios M. <ste...@gm...>]

Hello.

You could try to loop mount the root fs and check if there is an init
there. You could also boot it with bash as init (init=/bin/bash) and check
things.

Regards,
Steliosm
On Aug 6, 2013 9:30 PM, "Han" <kee...@gm...> wrote:

> Hi,
>
> I've built a root filesystem based off Debian Squeeze because I wanted to
> include all built (e.g. gcc) tools in.  However,  i was not able to boot
> the UML with this rootfs due to this error:
>
> <snip>
> Kernel panic - not syncing: No init found.  Try passing init= option to
> kernel.
> </snip>
>
> here is how I ran the UML:
>
> ./linux ubda=/nobackup/hxu2/uml/debian-root-fs mem=128M
>
> I also tried to add "init=/sbin/init" or "init=3" at the end, but got the
> same error.
>
> I believe I missed something when building the rootfs for the Init option.
> But what is it?  How should I set the init option in the rootfs?  please
> advise.
>
> thanks
> Han
>
>
>
>
> ------------------------------------------------------------------------------
> Get 100% visibility into Java/.NET code with AppDynamics Lite!
> It's a free troubleshooting tool designed for production.
> Get down to code-level detail for bottlenecks, with <2% overhead.
> Download for free and get started troubleshooting in minutes.
> http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
> _______________________________________________
> User-mode-linux-user mailing list
> Use...@li...
> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>
>