There are a lot of usefully MySQL commands that I either don’t run enough to remember or just end up using some GUI to accomplish. Nothing against Navicat, but what kind of sysadmin would I be if I couldn’t do it at the command line as well. Anyhow, I had to do a bunch of [...]
We use a lot of local zones in our Solaris 10 environment. We also use cfengine pretty heavily and there are some instances when we need to include or exclude certain automated tasks based on what type of zone we are working with. I wrote this little script that checks to see what type of [...]
In the past, I always had to use the ndd – get command to figure out what my link speed and duplex settings were. In Solaris 10, Sun now gives us the handy dladm command, which makes it a whole lot easier.
# dladm show-dev
e1000g2 link: up [...]
So you have used SVM to mirror your disk, and one of the two drives fails. Aren’t you glad you mirrored them! You don’t have to do a restore from tape, but you are going have to replace the failed drive.
Many modern RAID arrays just require you to take out the bad drive and plug [...]
Today, Friday February 13, at 3:31 PM (PST), the UNIX time will read exactly 1234567890. So exacly what is all this excitement about UNIX being able to count to 10? Surely, the operating system that is slowly but steadily putting Microsoft out of business must be able to do that. Well, it’s actually the UNIX [...]
It’s always a good idea to setup a local firewall on hosts that are on unprotected networks. The internet “winds” blow harder and harder each day, and it’s only a matter of time before some daemon has an exploit that gets taken advantage of. I use CentOS 5 for all my web servers, and here [...]
Unless you specify a different administrative file, the pkgadd command reads “/var/sadm/install/admin/default”, which specifies the base directory as “/opt”. Do not change the settings in this file, but rather create a custom admin file and enter an alternate “basedir” directive if you want to install your package into a different directory. We are going to [...]
Ever since coming to work at UC Santa Cruz, I have been feeling pretty lucky to work in a well engineered and managed datacenter. So lucky, in fact, that I’ve been cultivating hatred towards me in my former coworkers by regaling them with stories about how wonderfully designed everything is here. The problem with thinking [...]
Several weeks ago we started seeing some pretty scary errors showing up on the main system disk for our Blackboard server. We had an extra server hanging around, so we decided to move all the data off the failing disk and onto our spare server. The only question was how to make the new server [...]
Casey needed me to install APC cache for the Scriblio project. It’s a PECL module, and pecl install apc gives an error. Here are some great instructions for getting it all to work.
UPDATE: Casey actually has some instructions that provide a more elegant method of installing APC on CentOS or RHEL. Both methods will work, [...]
We backup our Oracle databases using RMAN and then write the backup pieces out to an NFS share. This has always worked well, but RMAN started complaining that the NFS share was not mounted with the correct options when we upgraded to Oracle 10G. After some poking around in the docs I finally came up [...]
Creating a properly offset slab of disk for Linux systems on your CLARiiON is not just a matter of creating a partition using the default fdisk values. The reason for this is that disk management utilities for Intel based systems generally write 63 sectors of metadata directly at the beginning of the LUN. The addressable [...]
If you’re running Solaris 8 or 9 and an upgrade results in broken SSH X11 forwarding, the problem may be Sun’s socfs bug. The symptom will be SSH’s failure to set the $DISPLAY variable and an error in your system log looking something like this:
Jun 3 09:40:24 servername sshd[26432]: [ID 800057 auth.error] error: Failed [...]
We just noticed that the time was very far off on our sparkly new VMware EXS 3.5 server. When I went to run ntpdate to bring it up to sync, I was suprised to find that it could not make a connection to the time server because outbound UDP 123 traffic was blocked by the [...]
Below is a list of RHEL system configuration changes that Oracle 10G requires before it is installed.
First, check the following kernel parameters using the commands below:
/sbin/sysctl -a | grep kernel.shmall
/sbin/sysctl -a | grep kernel.shmmax
/sbin/sysctl -a | grep kernel.shmmni
/sbin/sysctl -a | grep kernel.sem
/sbin/sysctl -a | grep fs.file-max
/sbin/sysctl -a | grep net.ipv4.ip_local_port_range
/sbin/sysctl -a | grep net.core.rmem_default
/sbin/sysctl [...]
