[Netkit.users] Too many netkit machines?

Gareth Lapworth glapworth at dmu.ac.uk
Wed Mar 16 21:16:42 CET 2011

Dear All,

I have just joined the list, so I do apologise if this has been asked
before - I have also searched the website, and looked through the
mailing list archives but I didn't seem to find an answer to my

I am in the process of building a netkit lab.  I have 37 of my
machines currently running but it seems that I have hit a wall and I
am unable to launch any more.  When I attempt to launch a further
machine, an xterm executes and quickly dies.  I ran the command
vstart vm --verbose --con0=this to see if I could catch the error
message before it disappeared,  The following data was displayed:

============= Starting virtual machine "vm" =============
   Kernel:     /opt/netkit/kernel/netkit-kernel
   Modules:    /opt/netkit/kernel/modules
   Memory:     32 MB
   Model fs:   /opt/netkit/fs/netkit-fs
   Filesystem: /home/glapworth/labs/ctec3427_cw2/nw-c/vm.disk (new)
   Hostfs at:  /home/glapworth

Running ==> /opt/netkit/kernel/netkit-kernel
modules=/opt/netkit/kernel/modules name=vm title=vm umid=vm mem=36M
root=98:1 uml_dir=/home/glapworth/.netkit/mconsole
hosthome=/home/glapworth con0=fd:0,fd:1 con1=null SELINUX_INIT=0
Locating the bottom of the address space ... 0x10000
Locating the top of the address space ... 0xc0000000
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking for tmpfs mount on /dev/shm...OK
Checking PROT_EXEC mmap in /dev/shm/...OK
Checking for the skas3 patch in the host:
  - /proc/mm...not found: No such file or directory
  - PTRACE_FAULTINFO...not found
  - PTRACE_LDT...not found
UML running in SKAS0 mode
Adding 2617344 bytes to physical memory to account for exec-shield gap

I can't see anything in this output that corresponds to a problem
other than the word "Terminated". The machine I am running on is a
quad core Xeon with 6Gb RAM running Ubuntu 10.04.  My system shows
that I have only used 647Mb RAM at the moment and therefore I should
have adequate to continue.  My CPU is happily running at 5% usage on
average so this shouldn't be too taxing on the hardware.

I've checked my file limits and I am not getting any too many open
files errors.  Any ideas or help would be greatly appreciated.

Thanks in advance.

All the best,

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