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Can't login in the Serial console.

  • 1.  Can't login in the Serial console.

    Posted Wed April 29, 2009 10:05 AM

    Originally posted by: SystemAdmin


    Hello All,

    I just installed AIX 5.3 into a p650 system (7038-6M2). It's working fine. I'm able to get into the system through telnet or SSH. But in the serial console I am not getting the LOGIN PROMPT. I tried with 5300-04-00 and then I upgrade it to 5300-08-03-0831. But no luck. I am getting the following message.

    0 Wed Apr 29 00:10:45 EDT 2009
    0 Wed Apr 29 00:10:45 EDT 2009 Checking for srcmstr active...
    0 Wed Apr 29 00:10:45 EDT 2009 complete
    0 Wed Apr 29 00:10:45 EDT 2009 Starting tcpip daemons:
    0 Wed Apr 29 00:10:53 EDT 2009 0513-059 The syslogd Subsystem has been started. Subsystem PID is 17052.
    0 Wed Apr 29 00:10:53 EDT 2009 0513-059 The inetd Subsystem has been started. Subsystem PID is 30224.
    0 Wed Apr 29 00:10:54 EDT 2009 0513-059 The portmap Subsystem has been started. Subsystem PID is 25624.
    0 Wed Apr 29 00:10:54 EDT 2009 0513-059 The xntpd Subsystem has been started. Subsystem PID is 27760.
    0 Wed Apr 29 00:10:54 EDT 2009 Finished starting tcpip daemons.
    0 Wed Apr 29 00:10:55 EDT 2009 nsmb0 Available
    0 Wed Apr 29 00:10:55 EDT 2009 Starting NFS services:
    0 Wed Apr 29 00:10:58 EDT 2009 0513-059 The biod Subsystem has been started. Subsystem PID is 25896.
    0 Wed Apr 29 00:10:59 EDT 2009 0513-059 The rpc.statd Subsystem has been started. Subsystem PID is 9844.
    0 Wed Apr 29 00:10:59 EDT 2009 0513-059 The rpc.lockd Subsystem has been started. Subsystem PID is 29518.
    0 Wed Apr 29 00:10:59 EDT 2009 Completed NFS services.
    0 Wed Apr 29 00:11:09 EDT 2009 0513-059 The ctrmc Subsystem has been started. Subsystem PID is 23274.

    After this no Console Login Prompt. Can any one tell me what to do now? I need the Serial console along with TN and SSH. Again the system is running fine.


  • 2.  Re: Can't login in the Serial console.

    Posted Wed April 29, 2009 04:21 PM

    Originally posted by: KentPerrier


    What is your console set to? You might not have a getty process running on tty0. Make sure your console is set correctly.


  • 3.  Re: Can't login in the Serial console.

    Posted Wed October 07, 2009 02:22 PM

    Originally posted by: d0_0b


    I also have the exact same problem. Did you find the solution?

    Many thanks,

    David


  • 4.  Re: Can't login in the Serial console.

    Posted Thu October 08, 2009 12:37 AM

    Originally posted by: SystemAdmin


    Run the command:

    lsdev -Cc tty

    You should see something like vty0 or tty0

    Let's assume you see vty0

    Then run:

    lsattr -El vty0 | grep login

    If it is set to disabled enable it with the command:

    chdev -l vty0 -a login=enable

    If you do not have a terminal defined, that is, lsdev -Cc tty did not display an output, from an remote session run "smit tty" ->add a tty->select the remaining as per your settings.

    On the final dialog screen there is an option "Enable Login", set it to enable.

    After doing this, the prompt still doesnt show up, change your serial cable and worst case scenario reboot the box.

    r/
    R


  • 5.  Re: Can't login in the Serial console.

    Posted Thu October 08, 2009 10:27 AM

    Originally posted by: d0_0b


    Hi rnoel,

    Thanks for the swift reply, I appreciate it.

    > Run the command:
    > lsdev -Cc tty

    
    [drobilla@tommy] ~ 
    {501
    }$ lsdev -Cc tty vty0 Available  Asynchronous Terminal vty1 Available  Asynchronous Terminal
    


    > Then run:
    > lsattr -El vty0 | grep login

    
    [drobilla@tommy] ~ 
    {502
    }$ lsattr -El vty0 | grep login login      enable                                                                                               Enable LOGIN                               True
    


    > After doing this, the prompt still doesnt show up, change your serial cable and worst case scenario reboot the box.

    Still no luck even after a reboot.

    Meanwhile, I've found that Serial Port Availability on p5 Servers which states:

    "The serial ports S1 and S2, at the rear of the system, are only available if the system is not managed using a HMC. In this case, the S1 and S2 ports support the attachment of the serial console and modem. If an HMC is connected, a virtual serial console is provided by the HMC (logical device vsa0 under AIX visible with the lsdev -l vsa0 command). When the HMC is connected, the S1 and S2 ports are not usable by applications, such as for an HACMP heartbeat."

    So I've tried running `lsdev -l vsa0` which returns this:

    
    [drobilla@tommy] ~ 
    {503
    }$ lsdev -l vsa0 vsa0 Available  LPAR Virtual Serial Adapter
    


    Hence I must assume this machine was installed via an HMC and the system is part of an LPAR.

    Problem is: we don't have an HMC.

    So I guess there must be some other way to connect to the HMC's network port on the back of the system in order to manage this box as an indivial one. Right?

    Thanks again,

    David


  • 6.  Re: Can't login in the Serial console.

    Posted Thu October 08, 2009 11:15 PM

    Originally posted by: SystemAdmin


    Hi David,

    The concept of S1 S2 being disabled totally slipped my mind. But since its disabled, I think I read in the first post that boot up messages appear and login prompt doesnt show up. Which port is this console connected to?

    Could you check if vty1 has login set to enable? If it is disabled, enable and retry the whole process.

    If you do not have a HMC, then you need to manage the server using IVM/ASMI (unless there is some other technique which I am unaware of). Check with IBM support or your documentation as to what the IP address of IVM is set to.

    This redpaper also gives info about IVM: http://www.redbooks.ibm.com/redpapers/pdfs/redp4061.pdf

    r/
    R


  • 7.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 10:37 AM

    Originally posted by: kellywh


    Hi,

    We just got a p520 and are seeing the exact same problem. We have no HMC, and this machine is brand new, never been connected to an HMC. The machine is not going to be partitioned, so no VIOS or IVM or HMC or anything is needed.

    I have a null modem cable connected to System Port #1. I get the SMS screens on this serial-attached console just fine, can interact with SMS (specify BOOTP parms, etc.) and the AIX console messages display during boot. The only problem is that I get no AIX login prompt after the last of the boot messages. I can log in via SSH, and I can echo a message to /dev/console and see it output on the serial-attached console device. I just don't get a login prompt at the console.

    I've installed both AIX 6100-03-01 and 5300-10-01, both via NIM mksysb install; same results in both instances.

    As far as I can tell, all the AIX devices and attributes look fine:

    >penable
    console
    >lscons
    /dev/vty0
    >ps -ef |grep getty
    root 192936 1 0 09:22:56 - 0:00 /usr/sbin/getty /dev/console
    lsattr -EHl vty0 -a login
    attribute value description user_settable

    login enable Enable LOGIN True

    I'd be grateful for any suggestions?

    Thanks,
    Bill


  • 8.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 11:13 AM

    Originally posted by: Montecarlo


    vty0 is a virtual terminal device. See prtconf output from an hmc connected p520 (we don't have any non-hmc connected)
    • vsa0 U9111.520.65F590E-V1-C0 LPAR Virtual Serial Adapter
    • vty0 U9111.520.65F590E-V1-C0-L0 Asynchronous Terminal

    The usb devices (for example) have completely different device addresses.

    + usbhc0 U787A.001.DPM05OQ-P1 USB Host Controller (33103500)
    + usbhc1 U787A.001.DPM05OQ-P1 USB Host Controller (33103500)

    I would expect to see tty devices with location codes similar to U787A.001.DPM05OQ

    Is there anything from prtconf that looks like a tty?
    Also, unless things have changed, IBM serial devices require almost all the control signals in order for the terminal to function.
    Regards, Simon


  • 9.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 01:39 PM

    Originally posted by: alethad


    For what it's worth we had a similar issue when we got our first p550. We don't partition our systems either. It might be a shot in the dark for a work around.

    I'm not sure if your model is similar to ours in that there is a serial port on the front of the box. We had to use this port because we weren't planning to use HMC's initially. We could plug our laptops into it and use the laptop as a console.

    I am not sure if that capability still exists or not. I was told by support at the time that it would be phased out on newer p systems. But I defer to those with more experience with the hardware side to correct me on this.

    Good luck.


  • 10.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 01:42 PM

    Originally posted by: kellywh


    Simon,

    Thanks for the reply.

    There are no tty devices that show up in AIX. Here's a portion of what I get out of lscfg/prtconf:

    • vsa1 U789C.001.DQD0T58-P1-T4 LPAR Virtual Serial Adapter
    • vty1 U789C.001.DQD0T58-P1-T4-L0 Asynchronous Terminal
    • vsa0 U789C.001.DQD0T58-P1-T3 LPAR Virtual Serial Adapter
    • vty0 U789C.001.DQD0T58-P1-T3-L0 Asynchronous Terminal

    I don't know why AIX finds/assigns device types of "LPAR Virtual" serial adapters (as opposed to "real" serial adapters), but that's what it's doing upon installation.

    As you can probably tell, I have no experience with AIX-native, un-partitioned, no-HMC, no-IVM boxes. So I'm not sure how the serial port actually should show up in AIX, but I assume AIX knows what it's doing.

    Since things work perfectly for the ASMI ASCII terminal menus and the SMS menus (including both display output and keyboard input), I'm assuming the terminal emulation settings (flow control, etc.) must be okay, although I tried making some changes just for kicks.

    And since AIX writes lots of nice messages to the display during boot, and I can do an 'echo "Hello there" >/dev/console' and it shows up on the display, I think AIX knows perfectly well where the console device is and is happy to write to it.

    It's just not willing to display a login prompt...

    Thanks,
    Bill


  • 11.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 03:57 PM

    Originally posted by: kellywh


    Alethad - thanks for the reply; no serial ports on the front side of the p520. Just the two "System Ports" on the rear.

    Regards,
    Bill


  • 12.  Re: Can't login in the Serial console.

    Posted Thu October 15, 2009 04:22 PM

    Originally posted by: kellywh


    Okay, I found my problem. I swapped out the null modem cable and poof it works fine now. I assume the old cable must've been pinned differently? The odd part is that the old cable worked well enough for the p520's ASMI and firmware/SMS screens to function fully, but not AIX.

    Whatever....thanks for you guys' help!

    Regards,
    Bill


  • 13.  Re: Can't login in the Serial console.

    Posted Fri October 16, 2009 04:23 AM

    Originally posted by: Montecarlo


    The swap out of the null modem cable is the key.
    As I mentioned, IBM serial devices require almost all modem signals before they will function.
    ASMI and AIX during boot are less strict about the required signals but once AIX is running and there is a getty on the line, you need all the modem control signals - specifically RTS, CTS, DSR, CD and DTR.
    Regards, Simon


  • 14.  Re: Can't login in the Serial console.

    Posted Fri October 16, 2009 04:57 AM

    Originally posted by: SystemAdmin


    Thats why in my last reply I had asked to change the cable. I have no explanation for it but it had worked for me in the past.

    The reason you might be seeing virtual LPAR terminals when you have no HMC and only a single LPAR is because IBM would have used a HMC during implementation and disconnected. Then you these virtual terminals and the actual serial adapters disabled. In the doc link which I had posted earlier, they have shown a technique to get the serial ports working again.

    r/
    R


  • 15.  Re: Can't login in the Serial console.

    Posted Mon October 19, 2009 03:59 PM

    Originally posted by: d0_0b


    Would it be possible for you to provide us with the exact pin connections of the cable that works?

    This way we could document it and have some custom built cables for our AIX machines.

    Many thanks,

    David


  • 16.  Re: Can't login in the Serial console.

    Posted Mon October 19, 2009 07:39 PM

    Originally posted by: dukessd


    http://www.unix.com/aix/49724-root-password-fresh-5-1-install-43p-140-a.html

    has your required pinout.

    p5/p6 default is 19,200:8:n:1

    For the p4 and earlier systems use:
    9,600:8:n:1

    HTH


  • 17.  Re: Can't login in the Serial console.

    Posted Tue October 20, 2009 08:18 AM

    Originally posted by: kellywh


    I don't think any sort of custom-made null modem cable is/was necessary. The 2nd cable I tried (the one that worked) is a brand new, clearly labelled null modem cable. Specifically, a "Cables to Go six foot DB9 F/F null modem/serial" cable, part number 03044. (I don't want to cut it up in order to get the pin/wiring connections!)

    I'm pretty sure any "real" null modem cable will work. The first cable I'd been using (the one that didn't work) was an older, not clearly labelled, found-in-a-drawer 9 pin female-to-female cable that had worked fine as a console cable on other devices (namely, F5 load balancing hardware). My mistake was in assuming that because that cable was pinned correctly enough for some things, it was a "real" null modem cable, I guess.

    Regards,
    Bill


  • 18.  Re: Can't login in the Serial console.

    Posted Mon October 26, 2009 10:51 AM

    Originally posted by: d0_0b


    @dukessd

    Thanks for the URL, that's exactly what I was looking for.

    @kellywh

    > I don't want to cut it up in order to get the pin/wiring connections!

    What, are you scared? lol. (Just kidding :)
    I'll need to do some found-in-a-drawer archeology just like you did. Whoohoo! If those don't work, I'll get a new one.

    Cheers,

    David


  • 19.  Re: Can't login in the Serial console.

    Posted Sat April 13, 2019 04:20 PM

    Originally posted by: PatrickVar


    For anyone coming across this post as I did, hopefully this additional information will be helpful. I was not able to get a console login due to the the vtyX device configuration. However, I also found that I needed to change the configuration on *all* vtyX devices, not just vty0. After eventually getting logged in on the console, I found that I ended up being connected via vty2 (I'm not clear how the S1/S2 ports I was physically connected to were mapped to vty devices). Another gotcha was that I needed to do a savebase/bosboot after making the changes in maintenance mode in order for them to stick. I'm not sure if both chdev commands are required, but these are the steps I took in my case:

    1. Boot into maintenance mode using install media that matches your OS version and access the root volume group.
    2. Check which vtyX devices you have:
    lsdev -Cc tty
    
    1. For each vty device shown, run the following commands. The second command adds "clocal" to runmodes and logmodes (you can use 'lsattr -El vty0' to see the current settings for both commands before changing):
    chdev -l vty0 -a login=enable
    chdev -l vty0 -a runmodes='hupcl,cread,brkint,icrnl,opost,tab3,onlcr,isig,icanon,echo,echoe,echok,echoctl,echoke,imaxbel,iexten,clocal' -a logmodes='hupcl,cread,echoe,cs8,clocal' -P
    
    1. Then run the following to save the changes:
    sync; sync; sync
    savebase
    bosboot -ad <boot_device>
    
    1. Reboot. 

    Again, I hope this help some other folks out there. I spent quite a bit of time trying to get my console working, so I hope I have helped some folks down the road.

     

    -Patrick