[Fedora-xen] Xen status for FC7

[Richard W.M. Jones]

Frank Morane wrote:
> I still can't get a console BUT I can access via ssh the booted domU; 
> then I saw nash using 95% of the cpu and I killed it.
> 
> The problem is that this is far from what I want since I cannot access 
> the domU via a console, when I try I get these:
> 
> printk: 185 messages suppressed.
> 4gb seg fixup, process ntpd (pid 1230), cs:ip 73:008ac17a
[...]
> and yes I have the "hwcap 0 nosegneg" in /etc/ld.so.conf.
> There is critical information missing to get older generation (Centos 4) 
> domU booting on late FC5, FC6 and FC7.

nosegneg only works if the kernel supports it, and as far as I can find 
out, this capability was only added relatively recently (earlier this year).

http://www.uwsg.iu.edu/hypermail/linux/kernel/0704.2/2872.html

In addition, this flags affects how (or rather, which) glibc is 
dynamically linked in to the binary.  /sbin/nash is statically linked, 
but /usr/sbin/ntpd is dynamically linked (at least on FC6, and I expect 
on FC5 too).

So if you're getting the above messages concerning ntpd, then it sounds 
a lot like you're still linking to a version of glibc which is using 
negative offsets with segment register overrides, which is something 
that Xen has to emulate, slowly.

As to how to fix this: In Debian the fix is well-known.  Rename the 
directory /lib/tls (on 64 bit Fedora: /lib64/tls) as /lib/tls.disabled, 
and reboot the domU.

Rich.

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