Unix tip: ZFS administration

Sandra Henry-Stocker, ITworld.com

From the looks of it, ZFS administration is significantly simpler than administration of other complex file systems such as Solaris Disk Suite and Veritas Volume Manager. You can get a lot more done with fewer commands and the chance of making an error that is difficult to back out of is practically non-existent. On the other hand, it's still new to most Unix sysadmins and even those of us who have been working with other Unix file systems such as ufs or efs are going to have to devote some time to getting used to new vocabulary, commands and ways of thinking. ...continue reading 'Unix tip: ZFS administration'

Rescuing files from lost+found

By Sandra Henry-Stocker

The lost+found directory included in (Unix) file systems is usually empty. Only used when fsck doesn't know what to do with files that have lost their place in the file system, they stand as a temporary holding place for those rare instances in which fsck can't put everything back together after file systems have become corrupt in some way. Moving the files back to their proper places in the OS and renaming them is largely an exercise in recognizing them and issuing the proper mkdir and mv commands to rebuild the contexts in which they previously resided. ...continue reading 'Rescuing files from lost+found'

The Sun system life cycle

By Sandra Henry-Stocker, ITworld

If you have ever tried to contract for hardware support for an older Sun system, you are undoubtedly aware of the fact that Sun systems eventually reach an "end of life" stage. This is the equivalent of a retirement age for computers, the date at which Sun informs customers that support for those systems is coming to an end. While the systems may still be performing extremely well, Sun maintenance will have been assigned a predictable end date. ...continue reading 'The Sun system life cycle'

Unix Tip: Using SCAT (Solaris CAT) for analyzing crash dumps

Sandra Henry-Stocker, ITworld.com

Want to do something with those crash dump files other than remove them? Want to extract some useful information without a lot of work? Take a look at Sun's free crash analysis tool, scat. ...continue reading 'Using SCAT (Solaris CAT) for analyzing crash dumps'

Unix Sleuthing: One problem leads to another

By Sandra Henry-Stocker, ITworld.com

When tracking down an unusual problem on a Unix system, you may encounter many turns and dead ends on the path toward the solution as some problems may have little connection to what first appears to be troubling your system. This is such a tale. ...continue reading 'Unix Sleuthing: One problem leads to another'

Unix Tip: Terminating unattended processes

By Sandra Henry-Stocker, ITworld

An easy way to terminate processes left running after users log off a system. ...continue reading 'Terminating unattended processes'

Unix Tip: More on bc

By Sandra Henry-Stocker, ITworld

In a previous column, we looked at bc, the surprisingly high precision and big value capable Unix tool that you will find on most versions of Unix today. The bc utility is not just a command line tool, however. You can also write numerically intensive scripts in bc. The tool incorporates enough syntax to assign values to variables, write and call functions, collect responses from users and print annotated results. ...continue reading 'Unix Tip: More on bc'

Using bc for big calculations

By Sandra Henry-Stocker, ITworld

For sysadmins who want to perform simple calculations on the command line, there's a considerably more useful tool than expr. Try bc.

Unix Tip: Burning bootable DVDs

By Sandra Henry-Stocker, ITworld.com

One of the messages that you don't want to see when getting ready to upgrade a system to Solaris 10 is "can't open boot device". The problems this kind of error suggests, such as bad CD/DVD reader or improper device alias, can be troublesome. So, when I ran into this problem on a Friday afternoon, I was not amused. I had tried various boot commands, but got the same basic response each time... continue reading 'Unix Tip: Burning bootable DVDs'

Unix Tip: Terminating Options Processing with --

Sandra Henry-Stocker, ITworld.com

Before we get beyond the topic of working around files and directories with oddball names, there's one more trick that's useful to know about -- how to terminate options processing with "--" (excuse the grammatical pun!). Typing -- within a Unix command essentially tells the shell to stop processing the text in the command line as if it contained command line options. ...continue reading 'Unix Tip: Terminating Options Processing with --'

Unix Tip: More on filenames

Sandra Henry-Stocker, ITworld.com

Two weeks ago, we looked at some tricks for displaying file names that include unprintable characters. Another -- and simpler -- way to do this is to use the -b option available with the ls command on some versions of Unix (e.g., Solaris), which forces a display of non-printable characters. ...continue reading 'Unix Tip: More on filenames'

Unix Tip: Stripping file extensions with the basename command

I recently discovered a new trick for using basename to extract filenames from a full pathnames. This can be useful if you want to extract some portion of a file's name and then reuse it. For example, if you want to find the differences between a number of files with .old extensions and the original files. ...continue reading 'Stripping file extensions with the basename command'

Unix tip: How-to rename an oddball file

By Sandra Henry-Stocker

Every now and then I come across a file that just doesn't display properly in a file listing. In fact, it can be a little tricky to determine the name of a file that contains odd characters. You might think a file's name is "myfile.txt" only to find out that it's really "myfile.txt " (note the extra blanks). Here's a way to rename it. ...continue reading 'How-to rename an oddball file'

Unix Tip: Shuffling file systems with rsync

By Sandra Henry-Stocker, ITworld

I recently found myself needing to move several very large file systems into roomier data quarters on a disk array and began thinking about the most efficient and reliable way to get the job done. ...continue reading 'Unix Tip: Shuffling file systems with rsync'

Unix Tip: Local message processing with syslog

By Sandra Henry-Stocker, ITworld

The syslog deamon (syslogd) on Unix systems provides message logging for other services so that each service doesn't have to duplicate the same basic functionality to manage logging for itself. The messages issued and their severity level depends on the applications, but where these messages are logged and how they are filtered when using the services of syslogd depends on how syslog is configured. The basic format of a line in syslog's configuration file specifies a message type and how messages matching the type will be handled. ...continue reading 'Local message processing with syslog'

Unix Tip: The crossover LAN

Sandra Henry-Stocker, ITworld.com

You have probably heard that a two-node LAN can be configured by stringing a crossover cable between the network ports on two systems. Not only is this true, but it's not all that hard to do provided you have a few tools, a length of CAT 5 cable and a couple RJ45 connectors. Using a crossover cable has one decided advantage over a traditional network hookup -- it avoids the requirement that a hub be used to connect the two systems, saving both money and rack space. So, let's examine what is needed to create your own crossover cable. ...continue reading 'Unix Tip: The crossover LAN'