LXC Logging

1. Guest OS enables /dev/ttyS2 on the guest application.

2. Guest application writes data to /dev/ttyS2.

3. Libvirt emulates /dev/ttyS2 to /dev/pts/x on the host.

4. IOXMAN gets the emulated serial device, /dev/pts/x from the XML file.

5. IOXMAN listens and reads available data from /dev/pts/x, sets the severity for the message, filters, parses and queues the message.

6. Start timer to send the message to /dev/log device on the host using errmsg.

7. Data is saved to the Cisco IOS syslog.

KVM Logging

1. Guest OS enables /dev/ttyS2 on the guest application.

2. Guest application writes data to /dev/ttyS2.

3. Libvirt emulates /dev/ttyS2 to /dev/pts/x on the host.

4. IOXMAN gets the emulated TCP path from the XML file.

5. IOXMAN opens an UNIX socket, and connects to the remote socket.

6. IOXMAN reads available data from the socket, sets the severity for the message, filters, parses, and queues the message.

7. Starts the timer to send the message to /dev/log device on the host using errmsg.

8. Data is saved to the Cisco IOS syslog.

LXC Tracing

1. Guest OS enables /dev/ttyS3 on the guest application.

2. Configures syslogd to copy message to /dev/ttyS3.

3. Guest application writes data to /dev/ttyS3.

4. Libvirt emulates /dev/ttyS3 to /dev/pts/y on the host.

5. IOXMAN gets the emulated serial device, /dev/pts/y from the XML file.

6. IOXMAN listens and reads available data from /dev/pts/y, filters, parses, and saves the message to IOx tracelog.

7. If IOx tracelog is full, IOXMAN rotates the tracelog file to /bootflash/tracelogs.

KVM Tracing

1. Guest OS enables /dev/ttyS3 on the guest application.

2. Configures syslog to copy the message to /dev/ttyS3.

3. Guest application writes data to /dev/ttyS3.

4. Libvirt emulates /dev/ttyS3 to TCP path on the host.

5. IOXMAN gets the emulated TCP path from the XML file.

6. IOXMAN opens an UNIX socket, and connects to the remote socket.

7. IOXMAN reads the available data from the socket, sets the severity level for the message, filters, parses, and saves the message to IOx tracelog.

8. If IOx tracelog is full, IOXMAN rotates the tracelog file to /bootflash/tracelogs.

Logging Messages in Cisco IOS Syslog

For any logging messages received from a guest application, IOXMAN sets the severity of the message to NOTICE by default, before sending it to the Cisco IOS syslog. When a message is received by IOSd, it is displayed on the console and saved on the syslog in the following message format:

To comply with the Cisco IOS syslog, the IOXMAN does support severity levels for logging messages. To report logging messages with severity, a guest application must append a header to the front of the message.

[a123b234,version,severity]

a123b234 is magic number.
Version:        severity support version.  Current version is 1.
Severity:       CRIT is 2
                ERR is 3
                WARN is 4
                NOTICE is 5
                INFO is 6
                DEBUG is 7

The following is an example of a message log:

echo “[a123b234,1,2]Guestshell failed” > /dev/ttyS2

Perform the following steps to report logging data from a guest application to the Cisco IOS syslog:

1. If you are using C programming, use write() to send logging data to the host.

   #define SYSLOG_TEST       “syslog test”
        int fd;
        fd = open("/dev/ttyS2", O_WRONLY);
        write(fd, SYSLOG_TEST, strlen(SYSLOG_TEST));
        close(fd);
   
   

2. If you are using a Shell console, use echo to send logging data to the host.

   echo “syslog test” > /dev/ttyS2
   
   

Tracing Message to IOx Tracelog

Perform the following steps to report tracing messages from a guest application to IOx tracelog:

1. If you are using C programming, use write() to send tracing message to the host.

   #define SYSLOG_TEST       “tracelog test”
        int fd;
        fd = open("/dev/ttyS3", O_WRONLY);
        write(fd, SYSLOG_TEST, strlen(SYSLOG_TEST));
        close(fd);
   
   

2. If you are using C programming, use syslog() to send tracing message to the host.

   #define SYSLOG_TEST       “tracelog test”
   
   syslog(LOG_INFO, “%s\n”, SYSLOG_TEST);
   
   

3. If you are using a Shell console, use echo to send tracing data to the host.

   echo “tracelog test” > /dev/ttyS3   
      or
   logger “tracelog test”