in retrospect…

HAPPY VALENTINES DAY, everyone!!

don’t do what i wouldn’t do…

the wife and i were googling for Philippine webhosts last night but we cannot find anything that will serve our needs… our requirements are the following:

• high disk space [at least 10GB]
• high bandwidth [at least 2GB/month]
• MySQL
• GD or ImageMagick for our Gallery
• an SSH connection [no FTP please!!]
• and of course, Apache and PHP

suffice it to say that all of these must be running in Linux [any flavor will do, really...] and most important of all, it must be dirt cheap!!

any ideas?? hmmm??

Ciao, sweetie…

currently somewhere attending our yearly MANCOM planning… we are now on our second — and hopefully the last — day of planning…

anyway, i was watching The Simpson’s last night before going to bed, and i heard the following exchanges between Bart and Liza:

Bart: why is it destroying other toys?
Liza: maybe it is after the competition…
Bart: you mean, like Microsoft?

their words, not mine… :d

Ciao, sweetie…

i recently acquired an AMD Athlon 64 3000+ processor using the VIA chipset. It supports the Ultra ATA 100/133 Bus Master IDE, a Serial-ATA (SATA) provided by VIA, and an extra SATA onboard controller by Silicon Image, complete with RAID function supporting RAID 0 (striping), 1 (mirroring), and 10 (striped arrays using mirrored arrays).

since i don’t need a striped array (where you have two or more hard disks, but the system sees them as one), i opted to create a RAID 1, or mirrored, array. this will be a high performance mirroring and duplexing array where there is “100% redundancy of data, no rebuild is necessary in case of a disk failure, just a copy to the replacement disk.”

i don’t know why, but i proceeded on creating a software raid (using SuSE 9.1 64) instead of a hardware raid using the SI controller. first thing i did was install the two disks using one of the controllers (remember the VIA and the SI controllers?), and started to boot into YAST (Yet Another Setup Tool) of SuSE. to be continued…

Ciao, baby… 8-)

server backup has always been the bane of a systems administrators’ existence… and finding the right backup utility and media is even worse! would you rather go for tape or writable CD? how about a magnetic drive? or a ZIP drive (that is, if you can still find these guys!)? and when do i backup? every night whenever no one’s around? or early in the morning? so does that mean i have to be here during those times?

okay, the long and shot of it is a big “NO”! that is if you are using rsync!

rsync, “is a tool for efficiently transferring files across a network”, this according to its documentation. but for me, this can be further written as “a tool to efficiently back up data across a network”… this is how it works:

we know that there are two types of backup; full backup and incremental backup (okay, three if you consider differential backup which to me, is not much different with incremental, except that you’d have to update the archive attributes yourself). for a further explanation on what these procedures are, please go to http://www.no-panic.com/backup/tech_supt/Procedures.html. we will be assuming you already know the differences between these procedures…

to use rsync, all you need is an idle box (installed with Linux, of course) and the rsync package installed on both the idle box (box A) and the server (box B) you want to back up. now, from box B, find out the specific files or directories you want to copy, and from box A, where you want to copy them to. it would be good practice to put the files in box A to where it was in box B, as you will find out later on.

and then, simply run this command from the console of box B:

rsynx -vupogtH -e=ssh /path/to/backup [ip/hostname]:/where/to/backup

and then, it will ask you for root’s password on box A, where:

-v = increase verbosity (of output/messages)
-u = update only (don´t overwrite newer files)
-p = preserve permissions
-o = preserve owner (root only)
-g = preserve group
-t = preserve times
-H = preserve hard links
-e=ssh = the connection protocol to use
/path/to/backup = the exact path of the files or directories you want to backup/copy (source)
[ip/hostname] = IP or hostname of the box you want to copy to (or from if done the othre way around)
where/to/backup = the exact location where you want to copy the files/directories (destination)

so, for example, i’d want to backup all directories under the home directory of my box B to the home directory of my box A having an IP of 192.168.0.2, my command would be:

rsync -vupogtH -e=ssh /home/* 192.168.0.2:/home/.

and this will copy all files during the first backup (full), and will only copy newer files during succeeding backups (incremental). read the rsync documentation or do “man rsync” on your linux console for more information on the flags of rsync.

for the actual backup to happen (incremental), what you can do is put the command you use in crontab and let it do the work for you… yes, even at 1 in the morning without the need for you to be at the office and running the command manually. click here to find out more about crontab.

now, for the best part. if, suddenly, box B decides to crash, you still have box A, with the exact same image (if you do everything right)! all you have to do is change the IP of the new box (box A) to what it was for box B, and voila! minimal downtime experienced and no need to copy from a backup image all the data you need (or want, or whatever)… nifty, eh?

so, the next time you are thinking of backing up your data and want full redundancy (okay, partial then) of your servers and its services, look at rsync… i guarranty that you won’t go wrong…

UP NEXT: dancing the Samba with Linux

current disposition: very happy i was able to do something very informative… not my usual drivel and ramblings… ehehehehe…

Ciao, baby… 8-)

Monday last week, my friend Marvin Johns called me up, with a very big problem… he said he just came from Singapore and bought an MSI K8T Neo and an Asus K8V SE Deluxe both sporting the new AMD Athlon 64 PIB. He also bought the latest SuSE Linux 9.0 64bit.

the problem, he is having a hard time using the Promise SATA RAID (redundant array of inexpensive disks) controller, and he would very much like to use these since, 1) it is there to use so why not?; and 2) it is a very new technology (at least for us) and wouldn’t it be a very big boost to our egos if we can install linux into these boxes? and besides, he already bought SATA hard disks! sayang naman kung hindi magagamit, right?

well, confronted with those challenges, i immediately asked him to bring the boxes to me… and so he does… he brought them that day also, and from then on, i suffered many a headaches in trying to install, simply because the installation cannot, for the life of me, find the hard disks… so i googled away with the search terms “Promise SATA linux driver“. well, suffice it to say that there were many links to those terms, but i never did find any that would help me in installing linux on the Promise.

That is, until an email came form Jesse Keating, a Linux Systems Engineer of Pogo Linux. What the email contains is a link to the SuSE 9.0 patch CD. This ISO apparently is a patch to the current SuSE 9.0 64bit CD (or DVD), which already contains drivers for SATA.

you guessed it, folks. i downloaded, i burned, and i installed… no sweat!

you only need to watch out for a few pitfalls, though.
# in the BIOS, instead of creating a RAID with the Promise, you need to configure it such that it sees the hard disks simply as IDE hard disks,
# delete the arrays if any (that is if the disks were previously configured as arrays); and
# if you really want to configure a RAID, use a software RAID, instead. this soooo much easier to use.

so, having these experiences with the SATA, i am now ready to do more jobs concerning these controllers… keep ‘em coming, you guys!!!

Ciao, baby… 8-)

Yaaayyyy!!!

For this term’s NETADDR (that is Net Addressing), I deviated from the norm. Instead of teaching IPv4 to my students, I instead tried to teach the newest version of the Internet Protocol, v6, or simply, IPv6.

Though not all applications (in Linux and otherwise) still allow for an IPv6 implementation, there are some which are, at least the important ones. I have students who are studying DNS, DHCP, Proxy, and Apache (httpd) implementations of IPv6. Will be posting links of packages as well as the configuration (conf) files of each of these applicaitons, so watch out for it.

Now, you will ask what is so important about IPv6? For one, once all devices require IP addresses (like PDAs, phones, cars, refrigerators, etc), the remaining IPv4 addresses will all be consumed. And the fact that the version 4 is already 20 years old!

By the way (highway), IPv6 has around 32 octillion addresses (please see above for a basic definition of numbers http://www.haravata.net/blog/index.php?p=24…

That’s it for now…

Ciao, baby… 8-)

Hey, guys… long time to see [or hear] [or read]

Well, anyway…. i just want to tell you guys that we now have a stable LTSP setup since early this month. Stable in a sense that the workstations can connect without problems to the server…

But what is LTSP?

The Linux Terminal Server Project (LTSP) from LTSP.org is a project by Jim McQuillan to enable the use of legacy computers using Linux running KDE or GNOME [or any window manager, for that matter]. One of the benefits of using LTSP is you save up on hard disks and you can still use your old classic Pentiums as workstations…

For our server setup, I installed Linux on an AMD Athlon XP 1.8GHz with 1BG of RAM and 80GB of hard disk space [all allocated for /home and mounted as /dev/hdb1]. The workstations are comprised of 16 units of Intel Celerons with 64MB of RAM each and using a 3COM 3C905B-TX LAN card, and 1 unit of a Pentium 200 with 32MB of RAM. All [servers and workstations] are connected together using CAT6 10/100 cables connected to a Linksys 16-port switch.rnrnPreviously, they were conencted to a 3COM hub. But when I started booting all of ‘em up, they started acting weird. Some cannot properly boot, while others experience collision left and right. So, I upgraded to the Linksys switch.

The workstations were booted by a single floppy disk. Disk images for specific LAN cards can be found at Etherboot.org. After booting up, each workstation will forget about their own CPU and RAM, and will just use the LAN card to connect to the server. And they will emulate the server, as if you are actually using the server… cool!!!

Anyway, do check it out at the LTSP.org site, or if you want to see a live implementation here at APC, just head on out to Room 506 and I’ll be glad to show you how it works…

Ciao, baby… 8-)

Recently, I answered a survey by one of our students. And I want to share with you my answers (with addendum):

Questions

1 Why use Linux?

I use Linux because:
a. it lets me configure/compile only those applications i want and i need;
b. it gives me the freedom to change any settings in my computer; and
c. it is free.

2 Is Linux for everyone?

There are two types of Linux: linux for the server & linux for the desktop. The server version is not for everyone nor for the faint of heart, I admit. They are used by developers and administrators. The desktop version, though, is for everyone.

3 What benefits can a person get from learning about Linux and its use?

The user is able to understand how applications work, how his computer internals interact with the operating system, how the operating system makes effective use of the computer peripherals in doing its work, etc, etc.

4 What are the uses of Linux?

Server:
file server (Samba)
web server (Apache)
database server (PostgreSQL/MySQL)
proxy server (Squid/SquidGuard)
domain name server (Bind)
firewall (IPChains/IPTables)
development (C/C++, Python, Ruby, Java, PHP)
application server

Desktop:
everything you can think of doing in a desktop

5 What are the differences between Linux and MS Windows?

There are lots of differences, I don’t even know where to begin. But, IMHO, I would say that the LICENSING marks the greatest differences between the two. The licensing of Windows states that only one computer unit must have the installation for the current license. This means that if you have more than one computer, you need to buy additional licenses for those as well.

With Linux under the GNU/GPL (GPL means General Public License. more about his later), you can install the OS in any number of computers. Also, GPL does not prevent the owner of the CD from burning additional copies of the CD and giving this out, or profiting from them, to other people as well, which you cannot definitely do with Windows.

6 Is Linux compatible with every desktop or Mac user?

Actually, it is. If you know how to use a pointing device (a mouse, for instance) to move and to point & click in either Windows or MacOS, you would definitely be able to use a Linux desktop, either GNOME or KDE.

But if you’d rather use the console (like I do) rather than the desktop, it would be a little harder if you haven’;t gone through DOS, and just zipped on by using Windows

7 Can Linux and MS Windows be installed in the same computer?

Dual-booting? Multi-booting even? Why, yes!

This can actually be done. What you need to do first is to install all the Windows version first, followed lastly by Linux. For example, you’d want to install Windows 98 SE, Windows 2000 Professional, Windows XP Professional, and Mandrake Linux 9.1 in your home desktop. First you’ll have to install the Windows OSes by year, meaning 98 first, 2000 second, and XP third. After this is done, you can finally install Linux.

This is because the OS loader of Windows does not recognize that of Linux, but they understand each other. So, after installing all three versions of Windows, you will see after booting up the three in a menu-like interface, waiting for you to make a choice between them.

When you instal Linux, it will install LILO (LInux LOader) as well into the MBR (master boot record). LILO understands Windows (and all its quirks) and will include all 3 in the menu of LILO.

8 What are the drawbacks in using Linux?

Drawbacks for whom and for what?

Whenever I am asked this, especially by supposed-to-be-technically-inclined people, I become sarcastic in a sense. Because the drawbacks they are really looking for are those that will drive the use of Linux to the ground. For desktop users, it will be the same drawbacks you experienced when you were first learning to use it.

But for the server, the only drawback (for others, not for me) is that all applications must be configured using a text file (what’s so hard about that?) and that you must understand all about paths, and daemons (not the evil kind), and processes (how and when to kill ‘em), and how to start/restart-stop a runnning daemon or process.

9 What is the meaning of the Linux GNU/GPL?< GNU/GPL means GNU's Not Unix/General Public License. By contrast with other licenses GNU/GPL "is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users". You can find out more from their site.

Number one, you can go to linuxiso.org and download Linux distributions from them or from their mirror sites. For beginners, I suggest you download first the KNOPPIX distribution. This is a live-cd which you can just pop in to your CD drive and run from the CD.

Number two, you can come to the ITRG office at the 5th floor, bring blank CDs, pay for CD burning, and we’ll burn your CD for you.

11 Which do you prefer: Linux or MS Windows or both?< Depends on the use actually. If I am playing a game I'd rather use Windows instead. But when I got copies of CrossOver Office and VMWare, Linux apps that emulates Windows, bugs and all, I deleted my NTFS partitions. Instead, I installed VMWare in my Linux desktop, and only boot to it whenever I want to play.

For serious work, I use Linux, period.

12 Why is the school (Asia Pacific College) not using Linux as their (desktop) operating system?

I have always pushed for the use of Linux in the desktop. But the arguments of those opposed range form “Linux is not yet a mature operating system” to “Linux is very hard to understand.” While these were true a few years back (like, I wouldn’t even think of migrating all our PCs, all 800+ of them, to Linux back in 1999), not anymore today.

Any computer-savvy kid can now install Linux in no time, and use KDE without even blinking an eye. It is now very mature that Microsoft itself said that in the Halloween Documents that they ARE afraid of the rise of Linux.

And of course, the instructors themselves teaching computer-related subjects are very application-centric. C++ instructors MUST teach them using Microsoft Visual C++, Groupware instructors must teach them Lotus Notes! Why? I ask you. Why do this if we can have license-free and headache free applications like GCC or phpGroupware as alternatives to these applications?

Of course, for the servers, we are using SuSE Linux versions 7.3 and 8.0. I am also now in the process of creating our own distribution. For lack of a more catchy name, I’ll be calling that (for now) APC Linux and I am currently in version 0.03.

So, thatt’s it for now, folks! Will APC finally wake up to the realization that Linux is the wave of the future (wave daw, o!!!)? Only time will tell…

Ciao, baby…

Yes! I have been out of it for a while due to the things I have to catch up on. The past two weeks saw me going from one place to another giving talks on Linux advocacy.

The first week, I along with a group of PLUGgers were hauled off to the City of Pines, all expenses paid, to talk at a symposium of the University of Baguio. Hosted by PLUGger Jopoy Solano (hey, Jops!) and the president of UB, we were billeted at the UB House, cared for by the HRM students. The talk was typical of PLUGgers: technical but very nice. In fact, we started at around 9:30 and ended around 7:30 in the evening. And every break in between, we were fed so many things I lost track of what they were. Feeling ko nga, para kameng patabaing baboy!!! hehehehe… We were brought to so many places and fed so much that everything was simply a whirlwind of going and eating.

Anyway, we all survived all that Baguio can offer (diba Dean??? *wink*), we left for Manila at around 3:30 in the afternoon of Sunday, making it to Manila at about 10:30 in the evening.

Pictures of all PLUG Roadshow sorties can be found here. These include the San Pablo Colleges talks, University of Baguio, and STI Sta Rosa seminars.

Last week, the 7th of March, we had another go at it, this time, in Sta Rosa Laguna. Systems Technology Institute-Sta Rosa invited us to speak in their Linux Seminar 2003, as part of their foundation day celebrations. As usual, we again got together to speak in behalf of our favorite OS.

But speaking about our favorite OS/distro is not the sole purpose of these gatherings. It is the friendship that comes with being together, talking about different topics of interest. Like, for example, during our first sortie in San Pablo City (see story below, It is nice to know there are still fresh young minds out there…) people learned all about the wonders rsync can do when it comes to a network backup. As well, we learned from Ariz Jacinto the way Heartbeat works. Two weeks ago, I learned all about the LFS (Linux From Scratch) project from Dean Michael Berris. Now, I have a working LFS, though still very far from being a production server. But it is working. And so on, and so on…

So, I am also encouraging everyone to be a part of this, as you will not only gain new knowledge, but gain new and lifelong friends as well who share the same goals and purposes as you.

Ciao, baby… 8-)