[opensuse] what's the alternative to console on serial?
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes. -- Per Jessen, Zürich (5.0°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Tue, Mar 15, 2016 at 1:38 PM, Per Jessen <per@computer.org> wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages?
I used netconsole when I had to capture oops output on console in the past. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Andrei Borzenkov wrote:
On Tue, Mar 15, 2016 at 1:38 PM, Per Jessen <per@computer.org> wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages?
I used netconsole when I had to capture oops output on console in the past.
On my first attempt, I just added netconsole to the initrd and the parameters as kernel arguments - this loaded netconsole too early, before the network interface was present :-) Still, I loaded it again once in the emergency shell, thanks! Funny old problem - mkinitrd didn't properly configure the initrd for nfsroot. I had to add -d /dev/nfs. -- Per Jessen, Zürich (7.4°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago.
I've not had reason to use one, sofar all my hardware has had at least one serial port. Still, I will order opne of those asap, good suggestion! -- Per Jessen, Zürich (7.4°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Tue, Mar 15, 2016 at 3:31 PM, Per Jessen <per@computer.org> wrote:
James Knott wrote:
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago.
I've not had reason to use one, sofar all my hardware has had at least one serial port. Still, I will order opne of those asap, good suggestion!
Do you miss serial port on a system, from which you want to capture messages, or on client used to capture them? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Andrei Borzenkov wrote:
On Tue, Mar 15, 2016 at 3:31 PM, Per Jessen <per@computer.org> wrote:
James Knott wrote:
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago.
I've not had reason to use one, sofar all my hardware has had at least one serial port. Still, I will order opne of those asap, good suggestion!
Do you miss serial port on a system, from which you want to capture messages, or on client used to capture them?
It would on the system from which I want to capture messages. Sofar it's only happened once, with this new Zotac box. -- Per Jessen, Zürich (7.1°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
15.03.2016 16:14, Per Jessen пишет:
Andrei Borzenkov wrote:
On Tue, Mar 15, 2016 at 3:31 PM, Per Jessen <per@computer.org> wrote:
James Knott wrote:
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago.
I've not had reason to use one, sofar all my hardware has had at least one serial port. Still, I will order opne of those asap, good suggestion!
Do you miss serial port on a system, from which you want to capture messages, or on client used to capture them?
It would on the system from which I want to capture messages. Sofar it's only happened once, with this new Zotac box.
Hmm ... according to this page this should be possible console=ttyUSB[<usb_port>[,<mode>] But this will require USB drivers built into kernel, and openSUSE have them as modules. http://www.tldp.org/HOWTO/Remote-Serial-Console-HOWTO/configure-kernel.html -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Andrei Borzenkov wrote:
15.03.2016 16:14, Per Jessen пишет:
Andrei Borzenkov wrote:
On Tue, Mar 15, 2016 at 3:31 PM, Per Jessen <per@computer.org> wrote:
James Knott wrote:
On 03/15/2016 06:38 AM, Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
You can get USB serial ports. I use one frequently at work and bought one myself several years ago.
I've not had reason to use one, sofar all my hardware has had at least one serial port. Still, I will order opne of those asap, good suggestion!
Do you miss serial port on a system, from which you want to capture messages, or on client used to capture them?
It would on the system from which I want to capture messages. Sofar it's only happened once, with this new Zotac box.
Hmm ... according to this page this should be possible
console=ttyUSB[<usb_port>[,<mode>]
But this will require USB drivers built into kernel, and openSUSE have them as modules.
Ah ... that is a problem. -- Per Jessen, Zürich (2.1°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 03/15/2016 08:38 AM, Andrei Borzenkov wrote:
I've not had reason to use one, sofar all my hardware has had at least
one serial port. Still, I will order opne of those asap, good suggestion!
Do you miss serial port on a system, from which you want to capture messages, or on client used to capture them?
Many mom boards still have a serial port and header connector, but it's not brought out to a rear panel connector. For those, it's possible to add the connector to have a standard serial port. Also, I believe serial port cards are still available for those systems that don't have a built in serial port. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2016-03-15 18:30, James Knott wrote:
Many mom boards still have a serial port and header connector, but it's not brought out to a rear panel connector.
My case exactly. I cheated: I looked for a board with that connection. At the time I was still sending faxes.
For those, it's possible to add the connector to have a standard serial port.
I did so. I had to find an old connector, then solder some wires to make it longer and reach the back of the box.
Also, I believe serial port cards are still available for those systems that don't have a built in serial port.
The problem are laptops. Many technicians on, er, hardware rooms, need to services things there that have a serial port for accessing. And, hey, their laptops don't have it now. Of course, the solution is to use an USB-rs232 adapter, but these things do not handle all the cables. Another problem are GPS receivers on serial ports. If you are interested in the time, with millisecond precision, you need a real serial port. The time on USB is not predictable. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
15.03.2016 21:22, Carlos E. R. пишет:
The problem are laptops. Many technicians on, er, hardware rooms, need to services things there that have a serial port for accessing. And, hey, their laptops don't have it now. Of course, the solution is to use an USB-rs232 adapter, but these things do not handle all the cables.
If you need them, you can get PC Card/Express Card serial adapter, they are true hardware serial ports. They are more expensive though (and not all notebooks have slots).
Le 15/03/2016 19:27, Andrei Borzenkov a écrit :
If you need them, you can get PC Card/Express Card serial adapter, they are true hardware serial ports. They are more expensive though (and not all notebooks have slots).
nearly no new laptop have them (they have USB3) - except may be on the pro market but my drugstore still use needle printer, I'm puzzled they can still find one :-) jdd -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2016-03-15 19:45, jdd wrote:
Le 15/03/2016 19:27, Andrei Borzenkov a écrit :
If you need them, you can get PC Card/Express Card serial adapter, they are true hardware serial ports. They are more expensive though (and not all notebooks have slots).
nearly no new laptop have them (they have USB3) - except may be on the pro market
but my drugstore still use needle printer, I'm puzzled they can still find one :-)
Oh, because there is a market for those. Many stores use them. Some for small rolls of thermal paper, some for writing forms with copies. Banks too. Try to google "impresora de agujas" (pin printer?), you hit many models being sold. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
jdd wrote:
Le 15/03/2016 19:27, Andrei Borzenkov a écrit :
If you need them, you can get PC Card/Express Card serial adapter, they are true hardware serial ports. They are more expensive though (and not all notebooks have slots).
nearly no new laptop have them (they have USB3) - except may be on the pro market
but my drugstore still use needle printer, I'm puzzled they can still find one :-)
There is large market for after-market service. Many businesses cannot just upgrade to the latest and greatest. -- Per Jessen, Zürich (1.9°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2016-03-16 07:45, Per Jessen wrote:
jdd wrote:
but my drugstore still use needle printer, I'm puzzled they can still find one :-)
There is large market for after-market service. Many businesses cannot just upgrade to the latest and greatest.
It is not just that. At lest in Spain, most shops use pin printers or thermal printers for the receipts. They are cheap and reliable. And they are a most if they need to generate carbon copies, which they must by regulations on the official bills. Thermal printers should be forbidden, though, for receipts: they fade. Similarly, banks use pin printers to fill forms with carbon copies, and in the machine that write on the passbooks. There is no alternative technology for this use. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
Carlos E. R. wrote:
On 2016-03-16 07:45, Per Jessen wrote:
jdd wrote:
but my drugstore still use needle printer, I'm puzzled they can still find one :-)
There is large market for after-market service. Many businesses cannot just upgrade to the latest and greatest.
It is not just that. At lest in Spain, most shops use pin printers or thermal printers for the receipts. They are cheap and reliable. And they are a most if they need to generate carbon copies, which they must by regulations on the official bills.
Thermal printers should be forbidden, though, for receipts: they fade.
Ride on, Don Quixote :-) Every POS system has a thermal printer for receipts today - so what if they fade in 12 months, you don't need them? (unless they're also warranty documents). -- Per Jessen, Zürich (3.4°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2016-03-16 10:07, Per Jessen wrote:
Carlos E. R. wrote:
Thermal printers should be forbidden, though, for receipts: they fade.
Ride on, Don Quixote :-)
X-)
Every POS system has a thermal printer for receipts today - so what if they fade in 12 months, you don't need them? (unless they're also warranty documents).
Often they are... when you claim a warranty, the receipt is needed, as proof of date of purchase. But some people have to keep receipts. Or use them for refunds, which you have to give to other people, which them store them in folders for 5 years in case of tax inspections. Knowing this, they then ask people to ask the shops for official receipts instead, meaning 5 minutes more at the store. Me, I make photos with a pocket camera of those receipts for archival ;-) -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
On 03/15/2016 02:22 PM, Carlos E. R. wrote:
The problem are laptops. Many technicians on, er, hardware rooms, need to services things there that have a serial port for accessing. And, hey, their laptops don't have it now. Of course, the solution is to use an USB-rs232 adapter, but these things do not handle all the cables.
That is precisely what I use one for at work. I use them for the console connection to routers etc. I have a collection of cables, for the various makes, that I connect to my USB serial adapter. I have cables for Cisco, Jupiter, Cienna and Zhone. I should also get one for Adtran. Anda uses a plain 9 pin port. Some Cisco gear also supports a mini USB to USB cable, with the USB-serial adapter built in. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Tuesday, 15 March 2016 11:38:47 EET Per Jessen wrote:
I'm trying to debug a problem with a system booting with root on NFS. I would have attached a serial console long ago and solved the problem, but this box doesn't have a serial port ... what's the alternative for getting access to those early messages? On start-up, the system is kicked into the emergency shell, and although I can easily mount the nfs root, when I try to resume the start-up, the system just crashes.
There's also kdump, which uses kexec to start a secondary kernel when the first crashes, allowing to save system logs and core, and perform analysis on them. -- Regards, Peter -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (6)
-
Andrei Borzenkov -
auxsvr -
Carlos E. R. -
James Knott -
jdd -
Per Jessen