It happens all the time. Sooner or later, every organization may run out of qualified admin staff because of various issues. So how do you deal with fresh out of school admins or other helping people in your organization?
Opensuse Linux version 11.0 has been released and available for download from mirrors
Firefox 3.0 has been released and the creators of Firefox 3.0 are aiming to set a world record for the most downloads in 24 hours.
There are a lot of flavors of Linux on the market, each with its own unique features and quirks. Businesses are usually willing to pony up for one of the “Big Two”: Red Hat or Novell/Suse. Regular folks, on the other hand, are more likely to download one of the free alternatives.
Good news for all Debian / Ubuntu Linux fans. Sun has started to offer Ubuntu Linux based servers. Sun has systems competitively priced for small and medium businesses. Ubuntu is based upon rock solid Debian core. Look like Red hat and Novell going to have some nice competition. Sun offers x64-based systems certified for Ubuntu Linux:
* x64 Rack Servers
* Blade Servers
* x64 Workstations
* Workgroup Disk Storage
* Tape Automation
=> Sun SMB Product Page (Via Arun’s blog)
SAP and Intel , the world’s biggest makers of business software and microchips, will jointly offer servers pre-packaged with SAP software aimed at medium-sized firms, the two companies said.
SAP aims to provide customers with a 45% savings on implementation and a 25% savings on total cost of ownership over what they’d typically spend for a comparable hardware/software combo, said Jans Peter Klaey, president of global SME at SAP, in an interview.
The server is available in five Northern European countries and should reach 20 countries this year.
=> SAP, Intel to offer out-of-the-box servers for SME’s
Yet another computer vendor started to support Linux on Desktop.
Now, Lenovo is finally joining Dell as one of the first top-tier PC vendors to offer pre-installed Linux desktops to its customers. On Aug-07-2007, Lenovo and Novell announced an agreement to provide preloaded Linux on Lenovo ThinkPad notebook PCs and to provide support from Lenovo for the operating system. The companies will offer SUSE Linux Enterprise Desktop 10 from Novell to commercial customers on Lenovo notebooks including those in the popular ThinkPad T Series, a class of notebooks aimed at typical business users, beginning in the fourth quarter of 2007. The ThinkPad notebooks with the Linux-preload will also be available for purchase by individual customers.
PC vendor Lenovo has promised ThinkPads with pre-installed Novell SUSE Linux Enterprise Desktop 10 for some time now. Lenovo will deliver the goods the week of Jan. 14.
Lenovo will release pre-installed SLED 10 on its Intel Centrino processor-powered ThinkPad T61 and R61 14-inch-wide notebooks. In February, Lenovo’s pre-integrated Novell Linux offering will expand to include some Penryn-based ThinkPads.
=> Read more …
rssh is a restricted shell for providing limited access to a host via ssh. It also allows system wide configuration and per user configuration. From the man page:
The user configuration directive allows for the configuration of options on a per-user basis. THIS KEYWORD OVERRIDES ALL OTHER KEYWORDS FOR THE SPECIFIED USER. That is, if you use a user keyword for user foo, then foo will use only the settings in that user line, and not any of the settings set with the keywords above. The user keywordâ€™s argument consists of a group of fields separated by a colon (:), as shown below. The fields are, in order:
- username : The username of the user for whom the entry provides options
- umask : The umask for this user, in octal, just as it would be specified to the shell access bits. Five binary digits, which indicate whether the user is allowed to use rsync, rdist, cvs, sftp, and scp, in that order. One means the command is allowed, zero means it is not.
- path : The directory to which this user should be chrooted (this is not a command, it is a directory name).
rssh examples of configuring per-user options
Open /etc/rssh.conf file:
# vi /etc/rssh.conf
All user tom to bypass our chroot jail:
Provide jerry cvs access with no chroot:
Provide spike rsync access with no chroot:
Provide tyke access with chroot jail located at /users
user="tyke:011:00001:/users" # whole user string can be quoted
if your chroot_path contains spaces, it must be quoted. Provide nibbles scp access with chroot directory:
user=nibbles:011:00001:"/usr/local/tv/shows/tom and jerry"
=> rssh home page
=> Redhat specific chroot jail script (outdated)
=> Refer man pages: rssh.conf, rssh, ssh, sshd, sftp, scp, rsync, sshd_config
Under Linux / UNIX you use lp command to print files from command prompt. lp is quite useful when GUI is not installed on Linux box to print files. The lp command is simply a front end command that calls the lpr command with appropriate options. Its main use is to allow the running of precompiled binary programs and scripts that assume that the lp command is the official printing command.
Changing papa size is very easy under GUI environment. But how do you change paper size under command prompt?
By default lp print to A4 paper size. However sometime you need to print to different paper size from command prompt such as A3 or A5. To print to A3 size, enter:
$ lp -o media=A3 /path/to/file
- -o media=size : Sets the page size to size. Most printers support at least the size names “a4”, “letter”, and “legal”.
Other useful examples
Print a double-sided legal document to a printer called “hpljf2”:
$ lp -d hpljf2 -o media=legal -o sides=two-sided-long-edge /path/to/file
Print an image across 4 pages using a printer called “epd2”:
$ lp -d epd2 -o scaling=200 filename
Print a text file with 12 characters per inch, 8 lines per inch, and a 1 inch left margin to a printer called “lpodc2”:
$ lp -d lpodc2 -o cpi=12 -o lpi=8 -o page-left=72 ~/info.txt
To know more about lp option, enter:
$ man lp
Please note that you need to configure print using CUPS configuration file /etc/cups/cupsd.conf or web based tool located at http://localhost:631/
(Fig 01: My CUPS Configuration, showing HP PhotoSmart Printer )
The open source journal has published an interesting hack. It mostly applies to high-end, multiple-disk storage:
Under the right conditions (that is, with certain hardware configurations which I’ll identify later) it is possible to literally double your sequential read performance from disk. If you noticed the terrible performance of the 3Ware 9500S RAID controller and cared enough to investigate. It all has to do with a sneaky little block device parameter known as readahead. Without going into too much gory detail, readahead controls how much in advance the operating system reads when, well, reading, as its name implies. By default, some operating systems (in particular, RHEL5 Server) sets this to 256 (512-byte sectors), or about 128 KB. When dealing with large filesystems spanning many disks, this paltry figure can actually nuke your performance.
=> HowTo: Linux: Double your disk read performance in a single command