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Posts in Solaris
Viewing function calls with whocalls
While catching up with various opensolaris.org mailing lists, I came across a post that described the whocalls utility. This nifty little utility can be used to view the stack frames leading up to a call to a specific function, which can be super useful for debugging. To view all of the code paths leading up to the printf function being called, whocalls can be run with the name of the function to look for, and the executable that we want to analyze for calls to that function: printf(0x80541b0, 0x8067800, 0x80653a8) /usr/bin/ls:pentry+0x593 /usr/bin/ls:pem+0xb1 /usr/bin/ls:pdirectory+0x266 /usr/bin/ls:main+0x70e /usr/bin/ls:_start+0x7a printf(0x80541b0, 0x8067a48, 0x80653a8) /usr/bin/ls:pentry+0x593 /usr/bin/ls:pem+0xb1 /usr/bin/ls:pdirectory+0x266 /usr/bin/ls:main+0x70e /usr/bin/ls:_start+0x7a < ..... > Now to do some research on the runtime linker's auditing facilities in /usr/lib/link_audit/*!
$ read more →Testing NTP services
Periodically I need to update my systems with new NTP server information. Since I have no idea if the remote servers are well kept, I tend to run ntpdate in test mode prior to starting ntpd or adding ntpdate to root's crontab. To run ntpdate in test mode, you can use the "-d" option: In addition to printing the timestamps, it also provides the offset the clock will be adjusted by. Certain applications dislike the time moving forward or back, which makes the ntpdate test option even more useful.
$ read more →Configuring the V40z SP to email home when problems occur
Having now worked with the Sun V40Z for more than a year, I can safely say that it is one of the best server platforms I have ever used. It has incredible lights out management, does a killer job of monitoring the platform environmentals, and can be configured to alert staff to problems it detects. All of these featured are made available through the service processor, which is an out-of-band device dedicated to monitoring and management. Since the service processor is constantly polling the platform environmentals, it knows immediately when a problem arises, and can be configured to send email or an SNMP trap with a detailed explanation of the issue that is detected…
$ read more →The power of the SMF Apache2 service
I am in the process of migrating some old Solaris 8 web servers to Solaris 10, and plan to use SMF to stop and start Apache. Solaris ships with a relatively recent release of Apache (if only it included the LDAP authentication module and PHP), which is nicely integrated with SMF. If your a *NIX admin, you gotta love the fact that SMF will restart processes for you:
$ read more →Recovering from Solaris hangs with the deadman timer
Periodically a nasty bug will rear it's head with Solaris or the latest build of Nevada, and the operating system will hang for no apparent reason. Recovering from a hang typically requires the administrator to reboot the host, which can delay the time it takes to get the system back to a working state. One nice feature built into Solaris to assist with system hangs is the deadman timer. When enabled, the deadman timer will cause a level 15 interrupt to fire on each CPU every second, which will in turn cause the kernel lbolt variable to be updated…
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