Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
try /dev/ttyS0 or /dev/ttyS1 for the serial ports.
John R Pierce wrote:
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
try /dev/ttyS0 or /dev/ttyS1 for the serial ports. _______________________________________________
Sorry, I am using ttyS0 no tty0 - using ttyS1 doesn't help either.
Am I doing this right? I press CTRL + A + M to Initialize Modem, or should I be issuing a different command to connect?
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
This works for me with our Cisco console cables: sudo yum install picocom sudo picocom /dev/ttyS0
BR Bent
Bent Terp wrote:
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
This works for me with our Cisco console cables: sudo yum install picocom sudo picocom /dev/ttyS0
BR Bent _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
but will that program work for other devices as well? this is a cheap D-Link layer2 managed switch.
Bent Terp wrote:
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
This works for me with our Cisco console cables: sudo yum install picocom sudo picocom /dev/ttyS0
BR Bent _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On which OS did you install this? On CentOS? If so, which repository did you have to add, cause I see the ones I have enabled doesn't have it?
[root@venus ~]# yum install picocom Loading "installonlyn" plugin Setting up Install Process Setting up repositories rpmforge 100% |=========================| 1.1 kB 00:00 base 100% |=========================| 1.1 kB 00:00 updates 100% |=========================| 951 B 00:00 addons 100% |=========================| 951 B 00:00 extras 100% |=========================| 1.1 kB 00:00 Reading repository metadata in from local files Parsing package install arguments Nothing to do
Bent Terp wrote:
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
This works for me with our Cisco console cables: sudo yum install picocom sudo picocom /dev/ttyS0
BR Bent _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
I have just noticed that there's no serial device loaded, yet I know it's enabled in the BIOS.
The only reference I could find in dmesg for serial ports is this:
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled r8169 Gigabit Ethernet driver 2.2LK-NAPI loaded GSI 20 sharing vector 0xC0 and IRQ 20 ACPI: PCI Interrupt 0000:01:00.0[A] -> GSI 20 (level, low) -> IRQ 20 eth0: Identified chip type is 'RTL8169s/8110s'.
[root@venus ~]# more /var/log/dmesg | grep ser Memory: 433664k/532480k available (2358k kernel code, 89936k reserved, 1325k data, 172k init) PCI: BIOS Bug: MCFG area at d0000000 is not E820-reserved pnp: 00:08: ioport range 0x400-0x4bf could not be reserved - User ID: CentOS (Kernel Module GPG key) serio: i8042 KBD port at 0x60,0x64 irq 1 serio: i8042 AUX port at 0x60,0x64 irq 12 8250_pnp: Unknown symbol serial8250_unregister_port 8250_pnp: Unknown symbol serial8250_register_port
So, it seems like there's no serial port in the Xen kernel, or am I missing something? How do I get the serial port to work in CentOS 5.1 + Xen?
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
That should work, but I usually use kermit which has a lot more options and is scriptable.
With kermit, try:
set line /dev/ttyS0 set carrier off (just in case the device doesn't raise CD) connect
then it is control-] followed by 'c' to get back to kermit.
Les Mikesell wrote:
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
That should work, but I usually use kermit which has a lot more options and is scriptable.
With kermit, try:
set line /dev/ttyS0 set carrier off (just in case the device doesn't raise CD) connect
then it is control-] followed by 'c' to get back to kermit.
where do I get kermit? yum install kermit returned no results
On Sun, Jun 22, 2008 at 09:57:08PM +0200, Rudi Ahlers wrote:
Les Mikesell wrote:
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
That should work, but I usually use kermit which has a lot more options and is scriptable.
With kermit, try:
set line /dev/ttyS0 set carrier off (just in case the device doesn't raise CD) connect
then it is control-] followed by 'c' to get back to kermit.
where do I get kermit? yum install kermit returned no results
I don't know, just offhand, where you can get a binary ready to install on Centos or RH.
But if you're not afraid to compile it yourself you can find it here: http://www.columbia.edu/kermit/ck80.html
Shouldn't be anything harder than unpacking the archive and typing "make linux".
Rudi Ahlers wrote:
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
That should work, but I usually use kermit which has a lot more options and is scriptable.
With kermit, try:
set line /dev/ttyS0 set carrier off (just in case the device doesn't raise CD) connect
then it is control-] followed by 'c' to get back to kermit.
where do I get kermit? yum install kermit returned no results
The machine where I use it is still running Centos 4.x - and it looks like it has been dropped from 5.x. If rpmfind doesn't locate a copy, the home for the kermit project is http://www.columbia.edu/kermit/ and C-kermit would be the version for Linux.
Les Mikesell wrote:
Rudi Ahlers wrote:
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
....dissertation on kermit deleted....
his problem is that he used /dev/tty0 and not the serial port /dev/ttyS0 note the big S. very important. /dev/tty0 is some kinda pseudothing. /dev/ttyS0 is the serial port known as COM1: in PC terms.
John R Pierce wrote:
Les Mikesell wrote:
Rudi Ahlers wrote:
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have changed the comms in minincom to use /dev/tty0 & the baud rate to 9600, yet I can't seem to connect with minicom. Does anyone know how to connect to a serial device from the console?
....dissertation on kermit deleted....
his problem is that he used /dev/tty0 and not the serial port /dev/ttyS0 note the big S. very important. /dev/tty0 is some kinda pseudothing. /dev/ttyS0 is the serial port known as COM1: in PC terms.
That was a typo in my first post. I am using /dev/ttyS0 - with a bit S :)
I have also noticed that there's no tty* in "dmesg | grep tty" or grep tty /var/log/demsg
could this be the problem / reason? I'm running CentOS 5.1 x64 with Xen 3.0 kernel
Rudi Ahlers wrote:
That was a typo in my first post. I am using /dev/ttyS0 - with a bit S :)
I have also noticed that there's no tty* in "dmesg | grep tty" or grep tty /var/log/demsg
could this be the problem / reason? I'm running CentOS 5.1 x64 with Xen 3.0 kernel
hmmm. 5.1 i686 w/o xen...
$ grep tty /var/log/dmesg serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A 00:0b: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A 00:0c: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
$ sudo setserial /dev/ttyS0 /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
$ sudo setserial /dev/ttyS1 /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
(old school pentium-III 800 on a i815 board)
John R Pierce wrote:
Rudi Ahlers wrote:
That was a typo in my first post. I am using /dev/ttyS0 - with a bit S :)
I have also noticed that there's no tty* in "dmesg | grep tty" or grep tty /var/log/demsg
could this be the problem / reason? I'm running CentOS 5.1 x64 with Xen 3.0 kernel
hmmm. 5.1 i686 w/o xen...
$ grep tty /var/log/dmesg serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A 00:0b: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A 00:0c: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
$ sudo setserial /dev/ttyS0 /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
$ sudo setserial /dev/ttyS1 /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
(old school pentium-III 800 on a i815 board) _______________________________________________
ok, so I think this is the problem then :)
[root@venus /]# grep tty /var/log/dmesg Xen virtual console successfully installed as ttyS0 [root@venus /]# setserial /dev/ttyS0 Cannot get serial info: Invalid argument [root@venus /]#
It may seem that Xen uses ttyS0 for itself, but how do I get around it?
Hi Rudi,
1) please TRIM the replies. 2) don't let people try to guess your setup - your initial email does not event state your CentOS version/arch - your should have told that you were using xen at the very beginning - post the relevant lines of /var/log/messages and/or the config files of the program(s) you are using: it will avoid typos such as tty0/ttyS0 ...
just like you did with: :D
[root@venus /]# grep tty /var/log/dmesg Xen virtual console successfully installed as ttyS0 [root@venus /]# setserial /dev/ttyS0 Cannot get serial info: Invalid argument [root@venus /]#
It may seem that Xen uses ttyS0 for itself, but how do I get around it?
show the grub.conf entry of your kernels (dom0/domU) and/or /proc/cmdline content.
Tru
Tru Huynh wrote:
Hi Rudi,
- please TRIM the replies.
- don't let people try to guess your setup
- your initial email does not event state your CentOS version/arch
- your should have told that you were using xen at the very beginning
- post the relevant lines of /var/log/messages and/or the config files of the program(s) you are using: it will avoid typos such as tty0/ttyS0
...
just like you did with: :D
[root@venus /]# grep tty /var/log/dmesg Xen virtual console successfully installed as ttyS0 [root@venus /]# setserial /dev/ttyS0 Cannot get serial info: Invalid argument [root@venus /]#
It may seem that Xen uses ttyS0 for itself, but how do I get around it?
show the grub.conf entry of your kernels (dom0/domU) and/or /proc/cmdline content.
Tru
Hi Tru
Sorry for the inconvenience, since this is a CentOS list, I didn't think it's necessary to say I'm using CentOS. And to be honest with you, I didn't think there's a problem on the server, but more that I didn't know how to use minicom - which was the case.
Only after people recommended a few other things, did I think of Xen.
Anyway, it's working now. I had to change the Xen config in /boot/grub/menu and tell Xen not to use ttyS0 as a serial console for itself. http://wiki.xensource.com/xenwiki/InstallationNotes#head-b915c65538e3d0cb29d...
On Mon, Jun 23, 2008 at 12:26:22PM +0200, Rudi Ahlers wrote:
Hi Tru
Hi Rudi,
Sorry for the inconvenience, since this is a CentOS list, I didn't think it's necessary to say I'm using CentOS.
We have 4 version of CentOS at the moment and a few arches for each. It's the minimum requirement to state the version and architecture.
I am running CentOS too, which information does that provide? If I say I am running CentOS-3.9 on i386/x86_64 that reduce the search scope for everyone reading your help request. :P
And to be honest with you, I didn't think there's a problem on the server, but more that I didn't know how to use minicom - which was the case.
I don't imply it has to be a problem on your server, but the more details you provide, the better. ;)
..
Anyway, it's working now. I had to change the Xen config in /boot/grub/menu and tell Xen not to use ttyS0 as a serial console for itself. http://wiki.xensource.com/xenwiki/InstallationNotes#head-b915c65538e3d0cb29d...
Great :)
Tru
On 23/06/2008, at 7:56 PM, Rudi Ahlers wrote:
Anyway, it's working now. I had to change the Xen config in /boot/ grub/menu and tell Xen not to use ttyS0 as a serial console for itself. http://wiki.xensource.com/xenwiki/InstallationNotes#head-b915c65538e3d0cb29d...
Good to hear it's working.
FYI, for future reference since not many people seem to know this, simple GNU 'screen' is also a terminal emulator and is *much* more simple than minicom, kermit, etc.
$ yum install screen $ screen /dev/ttyS0
'man screen' for more info.
Tom Lanyon wrote:
On 23/06/2008, at 7:56 PM, Rudi Ahlers wrote:
Anyway, it's working now. I had to change the Xen config in /boot/grub/menu and tell Xen not to use ttyS0 as a serial console for itself. http://wiki.xensource.com/xenwiki/InstallationNotes#head-b915c65538e3d0cb29d...
Good to hear it's working.
FYI, for future reference since not many people seem to know this, simple GNU 'screen' is also a terminal emulator and is *much* more simple than minicom, kermit, etc.
$ yum install screen $ screen /dev/ttyS0
'man screen' for more info. _______________________________________________
WOW, great tip!!! Thanx :)
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
issues like this which are not related to CentOS should be marked with an [OT] tag in the subject line as a start....
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have not been following this thread, but has minicom been suggested?
Barry
Barry Brimer wrote:
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
I have not been following this thread, but has minicom been suggested?
Barry _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Hi Barry
Yes, I am trying minicom, but have had no luck :(
Karanbir Singh wrote:
Rudi Ahlers wrote:
Hi all
I have a problem switch in our data centre, which is connected to a linux server via a serial cable. I know I can / could access the switch from my Windows PC back at the office, using hyperterm, but trying to access it using minicom just doesn't seem to work.
issues like this which are not related to CentOS should be marked with an [OT] tag in the subject line as a start....
I'm sorry, but I don't see the relevance. The switch is connected via serial cable to a CentOS 5.1 x64 server, and I need to connect to it from CentOS, but can't. Please explain to me how it's not related to CentOS?
The fact that I mentioned Windows, is purely to indicate that the serial port works, and it can be connected to via serial cable.
Isn't the switch accessible via a Web interface? Most are. If so, why not use a browser to access it? It is much more practical nowadays. Of course, I don't know your concrete case, I am thinking generally.
No virus found in this outgoing message. Checked by AVG. Version: 8.0.100 / Virus Database: 270.4.1/1513 - Release Date: 22-06-2008 7:52
Miguel Medalha wrote:
Isn't the switch accessible via a Web interface? Most are. If so, why not use a browser to access it? It is much more practical nowadays. Of course, I don't know your concrete case, I am thinking generally.
Yes, it was accessible via the web, until I changed the IP - but forgot to change the subnet mask as well. So, I could drive to the IDC and reset it, but this made me realize that I need to get serial console working for fixing / debugging purposes as well.
Luckily when I installed the switch, I connected the serial cable to the CentOS server as well, thought it would be a handy backup measure, until now.....
Yes, it was accessible via the web, until I changed the IP - but forgot to change the subnet mask as well. (...)
Can you configure some computer with a manual IP address and subnet mask to fit those the switch has now? You would then be able to change its setup.
No virus found in this outgoing message. Checked by AVG. Version: 8.0.100 / Virus Database: 270.4.1/1513 - Release Date: 22-06-2008 7:52
-
Barry Brimer -
Bent Terp -
fred smith -
John R Pierce -
Karanbir Singh -
Les Mikesell -
Miguel Medalha -
Rudi Ahlers -
Tom Lanyon -
Tru Huynh