Sometimes Solaris Volume Manager encounters a problem, such as being unable to write to a volume due to physical errors at the slice level. When problems occur, Solaris Volume Manager changes the status of the volume so that system administrators can stay informed. However, unless you regularly check the status in the Solaris Volume Manager GUI through the Solaris Management Console, or by running the metastat command, you might not see these status changes promptly.This chapter provides information about various monitoring tools that are available for Solaris Volume Manager One tool is the Solaris Volume Manager SNMP agent, which is a subagent of the Solstice Enterprise Agents monitoring software. In addition to configuring the this tool to report SNMP traps, you can create a shell script to actively monitor many Solaris Volume Manager functions. This shell script could run as a cron job and be valuable in identifying issues before they become problems.This is a list of the information in this chapter:Solaris Volume Manager Monitoring and Reporting (Task Map) Configuring the mdmonitord Command for Periodic Error Checking Solaris Volume Manager SNMP Agents Overview Configuring the Solaris Volume Manager SNMP Agents Limitations of the Solaris Volume Manager SNMP Agent Monitoring Solaris Volume Manager With a cron Job The following task map identifies the procedures that are needed to manage error reporting for Solaris Volume Manager.Task Description For Instructions Configure the mdmonitord daemon to periodically check for errors Configure the error-checking interval used by the mdmonitord daemon by editing the /lib/svc/method/svc-mdmonitor script. Configuring the mdmonitord Command for Periodic Error Checking Configure the Solaris Volume Manager SNMP agent Edit the configuration files in the /etc/snmp/conf directory so that Solaris Volume Manager will throw traps appropriately, to the correct system. Configuring the Solaris Volume Manager SNMP Agents Monitor Solaris Volume Manager with scripts run by the cron command Create or adapt a script to check for errors, then run the script from the cron command. Monitoring Solaris Volume Manager With a cron Job Solaris Volume Manager includes the /usr/sbin/mdmonitord daemon. When a disk fails, Solaris Volume Manager detects the failure and generates an error. This error event triggers the mdmonitord daemon to perform a check of RAID-1 (mirror) volumes, RAID-5 volumes, and hot spares. However, you can also configure this program to actively check for errors at an interval that you specify.Edit the /lib/svc/method/svc-mdmonitor script to add a time interval for periodic checking. Become superuser. Open the /lib/svc/method/svc-mdmonitor script in the editor of your choice. Locate the following section in the script:$MDMONITORD error=$? case $error in 0) exit 0 ;; *) echo "Could not start $MDMONITORD. Error $error." exit 0 Change the line that starts the mdmonitord command by adding a -t flag and the number of seconds between checks.$MDMONITORD -t 3600 error=$? case $error in 0) exit 0 ;; *) echo "Could not start $MDMONITORD. Error $error." exit 0 ;; esac Restart the mdmonitord command to activate your changes.# svcadm restart system/mdmonitorFor more information, see the mdmonitord1M man page. The Solaris Volume Manager SNMP trap agents requires the core packages SUNWlvmr, and the packages for the SUNWlvma and the Solstice Enterprise Agents. These core packages include the following: SUNWmibii SUNWsacom SUNWsadmi SUNWsasnm These packages are part of the Solaris operating system. They are normally installed by default unless the package selection was modified at install time or a minimal set of packages was installed. To confirm that these packages are available, use the pkginfo pkgname command, as in pkginfo SUNWsasnm. After you confirm that all five packages are available, you need to configure the Solaris Volume Manager SNMP agent, as described in the following section. The Solaris Volume Manager SNMP agents is not enabled by default. Use the following procedure to enable SNMP traps. Whenever you upgrade your Solaris operating system, you will probably need to edit the/etc/snmp/conf/enterprises.oid file and append the line in Step 6 again, then restart the Solaris Enterprise Agents server.After you have completed this procedure, your system will issue SNMP traps to the host or hosts that you specified. You will need to use an appropriate SNMP monitor, such as Solstice Enterprise Agents software, to view the traps as they are issued. Set the mdmonitord command to probe your system regularly to help ensure that you receive traps if problems arise. See Configuring the mdmonitord Command for Periodic Error Checking. Also, refer to Monitoring Solaris Volume Manager With a cron Job for additional error-checking options.Become superuser. Move the /etc/snmp/conf/mdlogd.rsrc– configuration file to /etc/snmp/conf/mdlogd.rsrc.# mv /etc/snmp/conf/mdlogd.rsrc- /etc/snmp/conf/mdlogd.rsrc Edit the /etc/snmp/conf/mdlogd.acl file to specify which hosts should receive SNMP traps. Look in the file for the following: trap = { { trap-community = SNMP-trap hosts = corsair { enterprise = "Solaris Volume Manager" trap-num = 1, 2, 3 }Change the line that contains hosts = corsair to specify the host name that you want to receive Solaris Volume Manager SNMP traps. For example, to send SNMP traps to lexicon, you would change the line to hosts = lexicon. If you want to include multiple hosts, provide a comma-delimited list of host names, as in hosts = lexicon, idiom. Also edit the /etc/snmp/conf/snmpdx.acl file to specify which hosts should receive the SNMP traps. Find the block that begins with trap = and add the same list of hosts that you added in the previous step. This section might be commented out with #'s. If so, you must remove the # at the beginning of the required lines in this section. Additional lines in the trap section are also commented out. However, you can leave those lines alone or delete them for clarity. After uncommenting the required lines and updating the hosts line, this section could look similar to the following:################### # trap parameters # ################### trap = { { trap-community = SNMP-trap hosts =lexicon { enterprise = "sun" trap-num = 0, 1, 2-5, 6-16 } # { # enterprise = "3Com" # trap-num = 4 # } # { # enterprise = "snmp" # trap-num = 0, 2, 5 # } # } # { # trap-community = jerry-trap # hosts = jerry, nanak, hubble # { # enterprise = "sun" # trap-num = 1, 3 # } # { # enterprise = "snmp" # trap-num = 1-3 # } } }Make sure that you have the same number of opening and closing brackets in the /etc/snmp/conf/snmpdx.acl file. Add a new Solaris Volume Manager section to the /etc/snmp/conf/snmpdx.acl file, inside the section you that uncommented in the previous step. trap-community = SNMP-trap hosts = lexicon { enterprise = "sun" trap-num = 0, 1, 2-5, 6-16 } { enterprise = "Solaris Volume Manager" trap-num = 1, 2, 3 }Note that the added four lines are placed immediately after the enterprise = “sun” block. Append the following line to the /etc/snmp/conf/enterprises.oid file:"Solaris Volume Manager" "1.3.6.1.4.1.42.104" Stop and restart the Solstice Enterprise Agents server.# /etc/init.d/init.snmpdx stop # /etc/init.d/init.snmpdx start The Solaris Volume Manager SNMP agent does not issue traps for all of the Solaris Volume Manager problems that system administrators need to be aware oft. Specifically, the agent issues traps only in the following instances:A RAID-1 or RAID-5 subcomponent goes into a “Needs Maintenance” state A hot spare is swapped into service A hot spare starts to resynchronize A hot spare completes resynchronization A mirror is taken offline A disk set is taken by another host and the current host panics Many problems, such as an unavailable disk with RAID-0 volumes or soft partitions on it, do not result in SNMP traps, even when reads and writes to the device are attempted. SCSI or IDE errors are generally reported in these cases. However, other SNMP agents must issue traps for those errors to be reported to a monitoring console. To automatically check your Solaris Volume Manager configuration for errors, create a script that the cron utility can periodically run.The following example shows a script that you can adapt and modify for your needs.This script serves as a starting point for automating error checking for Solaris Volume Manager. You probably need to modify this script for your own configuration. &sample-cron;For information on invoking scripts by using the cron utility, see the cron1M man page.