Evan Lavelle
2007-Dec-13 23:21 UTC
[Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
I''ve just installed Fedora 8 / xen-2.6.21 on a headless server, but I can''t get a serial console login on the Xen version of the kernel. 1 - If I boot into 2.6.23.8-63.fc8, the serial console login works as expected 2 - If I boot into 2.6.21-2952.fc8xen instead, I get all the expected serial output up to the end of the boot process, but no login. When I boot into the xen kernel, inittab is modified, and the modification removes the agetty on ttyS0. If I compare the old inittab with the new inittab, I get: 46,47c46 < # co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav < co:12345:respawn:/sbin/agetty ttyS0 115200 vt100 --- > co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav In other words, a commented entry was uncommented, and the following line was deleted, which explains why I can''t log in. This is so bizarre that it almost looks like it was done on purpose (was it ? :)) Anyone seen this? Any ideas? Thanks - Evan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Sadique Puthen
2007-Dec-14 09:48 UTC
Re: [Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
Can I see your grub.conf from dom0 and the output of "dmesg | grep tty" from the same? --Sadique Evan Lavelle wrote:> I''ve just installed Fedora 8 / xen-2.6.21 on a headless server, but I > can''t get a serial console login on the Xen version of the kernel. > > 1 - If I boot into 2.6.23.8-63.fc8, the serial console login works as > expected > > 2 - If I boot into 2.6.21-2952.fc8xen instead, I get all the expected > serial output up to the end of the boot process, but no login. > > When I boot into the xen kernel, inittab is modified, and the > modification removes the agetty on ttyS0. If I compare the old inittab > with the new inittab, I get: > > 46,47c46 > < # co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav > < co:12345:respawn:/sbin/agetty ttyS0 115200 vt100 > --- > > co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav > > In other words, a commented entry was uncommented, and the following > line was deleted, which explains why I can''t log in. This is so > bizarre that it almost looks like it was done on purpose (was it ? :)) > > Anyone seen this? Any ideas? > > Thanks - > > Evan > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Evan Lavelle
2007-Dec-14 10:28 UTC
Re: [Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
Sadique Puthen wrote:> > Can I see your grub.conf from dom0 and the output of "dmesg | grep tty" > from the same?Sure- see below. Thanks - Evan ======================== [root@thor evan]# dmesg | grep tty Command line: ro root=/dev/VolGroup00/LogVol01 rhgb quiet console=ttyS0,115200n81 Kernel command line: ro root=/dev/VolGroup00/LogVol01 rhgb quiet console=ttyS0,115200n81 serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A 00:0a: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A ========================grub.conf (there are 4 entries, because the FC8 updater got a new version of Xen (2.6.21-2952) just after installation; I think it described this as a bugfix): default=1 timeout=10 serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1 terminal --timeout=10 serial console title Fedora (2.6.23.8-63.fc8) root (hd0,0) kernel /vmlinuz-2.6.23.8-63.fc8 ro root=/dev/VolGroup00/LogVol01 rhgb quiet console=ttyS0,115200n81 initrd /initrd-2.6.23.8-63.fc8.img title Fedora (2.6.21-2952.fc8xen) root (hd0,0) kernel /xen.gz-2.6.21-2952.fc8 com1=115200,8n1 module /vmlinuz-2.6.21-2952.fc8xen ro root=/dev/VolGroup00/LogVol01 rhgb quiet console=ttyS0,115200n81 module /initrd-2.6.21-2952.fc8xen.img title Fedora (2.6.21-2950.fc8xen) root (hd0,0) kernel /xen.gz-2.6.21-2950.fc8 module /vmlinuz-2.6.21-2950.fc8xen ro root=/dev/VolGroup00/LogVol01 rhgb quiet module /initrd-2.6.21-2950.fc8xen.img title Fedora-base (2.6.23.1-42.fc8) root (hd0,0) kernel /vmlinuz-2.6.23.1-42.fc8 ro root=/dev/VolGroup00/LogVol01 rhgb quiet initrd /initrd-2.6.23.1-42.fc8.img ==================================================== _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
David Stone
2007-Dec-17 15:09 UTC
Re: [Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
Here''s what I do on an F7 system with a built Xen 3.2 and Xenified Linux kernel from the Xen soure: (2.6.18): Add the folloing line to /etc/inittab (after the rest of the getty lines) s1:12345:respawn:/sbin/agetty -L 115200 ttyS0 vt100 Add "ttyS0" to /etc/securetty (Reboot) For Xen/Dom0: On Xen "command line" (in grub.conf) add: com1=115200,8n1 On Xenified Linux "command line" (in grub.conf) add: console=ttyS0, 115200 It works for me no problem...it looks like you''re doing more or less the same thing? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Evan Lavelle
2007-Dec-17 16:20 UTC
Re: [Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
David Stone wrote:> Here''s what I do on an F7 system with a built Xen 3.2 and Xenified > Linux kernel from the Xen soure: (2.6.18): > > Add the folloing line to /etc/inittab (after the rest of the getty lines) > s1:12345:respawn:/sbin/agetty -L 115200 ttyS0 vt100 > Add "ttyS0" to /etc/securetty > (Reboot) > For Xen/Dom0: > On Xen "command line" (in grub.conf) add: com1=115200,8n1 > On Xenified Linux "command line" (in grub.conf) add: console=ttyS0, 115200 > > It works for me no problem...it looks like you''re doing more or less > the same thing?Yes, looks pretty much the same: grub.conf: kernel /xen.gz-2.6.21-2952.fc8 com1=115200,8n1 module /vmlinuz-2.6.21-2952.fc8xen ro root=/dev/VolGroup00/LogVol01 rhgb quiet console=ttyS0,115200n81 inittab: co:12345:respawn:/sbin/agetty ttyS0 115200 vt100 The inittab/securetty settings work Ok when booting the non-Xen kernel, but not when booting the Xen kernel. Normally, for non-Xen, I get all of the BIOS output, the grub output, the kernel boot output, and a login on ttyS0. On the Xen kernel, I get everything except the login (and I also get the Xen booting stuff). I tried swapping my ''co'' inittab entry for your ''si'' inittab entry, but it made no difference. I got a reply on fedora-xen, saying that inittab actually *is* modified duirng Xen booting, and it looks like there''s an error in the modification. However, this isn''t the whole story. I''ve swapped around my inittab a bit, and it''s no longer modified, but I *still* don''t get a login. On both my old and new innitabs I get a message like this every 5 mintues in the system log and on the ttyS0 output: INIT: Id "s1" respawning too fast: disabled for 5 minutes (this is using your "s1" line). This basically seems to mean that the agetty entry in inittab is incorrect, even though (1) (in this case) it wasn''t modified by FC8 and/or Xen, and (2) I know it''s correct because it works on the un-Xenned kernel. ??? Evan> _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Tom Brown
2007-Dec-30 09:29 UTC
Re: [Xen-users] inittab corrupted/serial console broken on Xen-ified kernel?
On Mon, 17 Dec 2007, Evan Lavelle wrote:> David Stone wrote: >> Here''s what I do on an F7 system with a built Xen 3.2 and Xenified >> Linux kernel from the Xen soure: (2.6.18): >> >> Add the folloing line to /etc/inittab (after the rest of the getty >> lines) >> s1:12345:respawn:/sbin/agetty -L 115200 ttyS0 vt100 >> Add "ttyS0" to /etc/securetty >> (Reboot) >> For Xen/Dom0: >> On Xen "command line" (in grub.conf) add: com1=115200,8n1 >> On Xenified Linux "command line" (in grub.conf) add: console=ttyS0, >> 115200 >> >> It works for me no problem...it looks like you''re doing more or less >> the same thing? > > Yes, looks pretty much the same: > > grub.conf: > kernel /xen.gz-2.6.21-2952.fc8 com1=115200,8n1aren''t you missing the console=com1 part of the above line? Without that I think you''re likely to be screwed. You''re not telling XEN to grab the serial port, and the default XENified kernels don''t usually have "real" serial port drivers in them... at least they didn''t used to.... what is confusing is that your dmesg output from http://lists.xensource.com/archives/html/xen-users/2007-12/msg00486.html shows ttyS1 ... but NO ttyS0, which pretty much explains why agetty can''t open it and keeps exiting... causing init to whine about it respawning too fast. (but without serial drivers, I wouldn''t have expected to see a ttyS1, which is confusing the daylights out of me.) you might try using mgetty instead of agetty, it has better logging (better everything except size and simplicity:). You can also try a simple echo testing > /dev/ttyS0 and see if that generates output or a "no such device" error.> module /vmlinuz-2.6.21-2952.fc8xen ro root=/dev/VolGroup00/LogVol01 > rhgb quiet console=ttyS0,115200n81 > > inittab: > co:12345:respawn:/sbin/agetty ttyS0 115200 vt100<snip> I''ve got several pairs of xen machines, where each is connected to the console of the other. AFAIK that doesn''t work with the default xen linux kernel builds, due to the missing serial drivers. Basically XEN replaces the serial layer so it can provide a fake serial console that knows about the hypervisor... at least it used to. It would be really nice if the situation has improved to the point where the hypervisor and linux can both dump console output on one serial port, and you can actually use a different serial port with minicom. (Maybe that''s what xvc0 is about!?) In my experience, you need to custom compile a kernel, and NOT give XEN the console=com1 parameter to let the linux console run on ttyS0 and be able to access ttyS1 from minicom ... but AFAIK, that is rambling and not related to your question. -Tom _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users