Disclaimer
The opinions expressed herein are my own personal opinions and do not represent anyone else's view in any way, including those of my employer.
© Copyright 2008
The opinions expressed herein are my own personal opinions and do not represent anyone else's view in any way, including those of my employer.
© Copyright 2008
I am writing this in response to a question it seems I receive daily:
“What do you use to download movies and apps?”
So you are looking to download music, movies, or applications but those old P2P network such as Gnutella, Edonkey, and Freenet(think KaZaa, BearShare, Shareaza) just arent cutting it anymore.
Not only are these networks insecure and the clients used to connect to them full of spyware, but they are also outdated as Bittorent has become the standard for file sharing on the internet.
Here I will give a detailed(as much as I can) explanation of what BitTorrent is and how it compares to other methods of sharing files. I will post a detailed account of actually using a bittorrent client to download (and of course upload) files.
So…
BitTorrent is a protocol designed for transferring files. It is peer-to-peer in nature, as users connect to each other directly to send and receive portions of the file. However, there is a central server (called a tracker) which coordinates the action of all such peers. The tracker only manages connections, it does not have any knowledge of the contents of the files being distributed, and therefore a large number of users can be supported with relatively limited tracker bandwidth. The key philosophy of BitTorrent is that users should upload (transmit outbound) at the same time they are downloading (receiving inbound.) In this manner, network bandwidth is utilized as efficiently as possible. BitTorrent is designed to work better as the number of people interested in a certain file increases, in contrast to other file transfer protocols.
One analogy to describe this process might be to visualize a group of people sitting at a table. Each person at the table can both talk and listen to any other person at the table. These people are each trying to get a complete copy of a book. Person A announces that he has pages 1-10, 23, 42-50, and 75. Persons C, D, and E are each missing some of those pages that A has, and so they coordinate such that A gives them each copies of the pages he has that they are missing. Person B then announces that she has pages 11-22, 31-37, and 63-70. Persons A, D, and E tell B they would like some of her pages, so she gives them copies of the pages that she has. The process continues around the table until everyone has announced what they have (and hence what they are missing.) The people at the table coordinate to swap parts of this book until everyone has everything. There is also another person at the table, who we’ll call ‘S’. This person has a complete copy of the book, and so doesn’t need anything sent to him. He responds with pages that no one else in the group has. At first, when everyone has just arrived, they all must talk to him to get their first set of pages. However, the people are smart enough to not all get the same pages from him. After a short while they all have most of the book amongst themselves, even if no one person has the whole thing. In this manner, this one person can share a book that he has with many other people, without having to give a full copy to everyone that’s interested. He can instead give out different parts to different people, and they will be able to share it amongst themselves. This person who we’ve referred to as ‘S’ is called a seed in the terminology of BitTorrent. There’s more about the various terms in a later section.
The most common method by which files are transferred on the Internet is the client-server model. A central server sends the entire file to each client that requests it — this is how both http and ftp work. The clients only speak to the server, and never to each other. The main advantages of this method are that it’s simple to set up, and the files are usually always available since the servers tend to be dedicated to the task of serving, and are always on and connected to the Internet. However, this model has a significant problem with files that are large or very popular, or both. Namely, it takes a great deal of bandwidth and server resources to distribute such a file, since the server must transmit the entire file to each client. Perhaps you may have tried to download a demo of a new game just released, or CD images of a new Linux distribution, and found that all the servers report “too many users,” or there is a long queue that you have to wait through. The concept of mirrors partially addresses this shortcoming by distributing the load across multiple servers. But it requires a lot of coordination and effort to set up an efficient network of mirrors, and it’s usually only feasible for the busiest of sites.
Another method of transferring files has become popular recently: the peer-to-peer network, systems such as Kazaa, eDonkey, Gnutella, Direct Connect, etc. In most of these networks, ordinary Internet users trade files by directly connecting one-to-one. The advantage here is that files can be shared without having access to a proper server, and because of this there is little accountability for the contents of the files. Hence, these networks tend to be very popular for illicit(and I say that loosely) files such as music, movies, pirated software, etc. Typically, a downloader receives a file from a single source, however the newest version of some clients allow downloading a single file from multiple sources for higher speeds. The problem discussed above of popular downloads is somewhat mitigated, because there’s a greater chance that a popular file will be offered by a number of peers. The breadth of files available tends to be fairly good, though download speeds for obscure files tend to be low. Another common problem sometimes associated with these systems is the significant protocol overhead for passing search queries amongst the peers, and the number of peers that one can reach is often limited as a result. Partially downloaded files are usually not available to other peers, although some newer clients may offer this functionality. Availability is generally dependent on the goodwill of the users, to the extent that some of these networks have tried to enforce rules or restrictions regarding send/receive ratios.
Use of the Usenet binary newsgroups is yet another method of file distribution, one that is substantially different from the other methods. Files transferred over Usenet are often subject to miniscule windows of opportunity. Typical retention time of binary news servers are often as low as 24 hours, and having a posted file available for a week is considered a long time. However, the Usenet model is relatively efficient, in that the messages are passed around a large web of peers from one news server to another, and finally fanned out to the end user from there. Often the end user connects to a server provided by his or her ISP, resulting in further bandwidth savings. Usenet is also one of the more anonymous forms of file sharing, and it too is often used for illicit files of almost any nature. Due to the nature of NNTP, a file’s popularity has little to do with its availability and hence downloads from Usenet tend to be quite fast regardless of content. The downsides of this method include a baroque set of rules and procedures, and requires a certain amount of effort and understanding from the user. Patience is often required to get a complete file due to the nature of splitting big files into a huge number of smaller posts. Finally, access to Usenet often must be purchased due to the extremely high volume of messages in the binary groups.
BitTorrent is closest to Usenet, in my opinion. It is best suited to newer files, of which a number of people have interest in. Obscure or older files tend to not be available. Perhaps as the software matures a more suitable means of keeping torrents seeded will emerge, but currently the client is quite resource-intensive, making it cumbersome to share a number of files. BitTorrent also deals well with files that are in high demand, especially compared to the other methods.
There are several choices here, because unlike some peer to peer applications (such as Kazaa), the BitTorrent implementation is open source. This means that programmers are free to take the source code to the program and modify it, if they feel there is something they’d like to change. Here are the various clients of which I am aware. As a note I use Azureus(Vuze) exclusivley on Linux and Windows. It has a great set of features and is easy to configure and learn. It is somewhat CPU and Memory intensive so a strong CPU(3Ghz+) and 1GB+ of memory is highly recomended for optimal performance. It will certainly work fine with a less powerful machine but dont expect to get much other work done.
I have not personally evaluated it yet.Most of the clients that are pure Python/wxPython (e.g. the official BitTorrent client, Eike Frost’s experimental, Shad0w’s experimental) will run under *BSD/Linux without problems. The source code tarballs for all of these clients are available at the home pages; see the links above. Clients written in other cross-platform languages such as Java (e.g. Azureus) should also work.
The biggest challenge to running a BT client under *BSD/Linux is getting the required libraries installed. At a minimum you will need Python 2.2 or greater. If you want to use the ‘-gui’ versions of the clients you will also need wxWindows, which has Python bindings called wxPython. These should all be available as packages for your system. Your first step should be to consult your distribution’s package system and get these prerequisites installed.
For Debian systems there is a package called bittorrent, which requires the python 2.2 package. You should also install the packages libwxgtk2.4-python and mime-support, if you plan to use the GUI version of the client.
If you are using Mandrake with Cooker, you might want to try the RPMs listed here.
Below are some general instructions for installing on a Unix/Linux system.
Install Python, preferably version 2.2. You can run “python -V” to see what version you currently have installed, if any. Also, you may have multiple versions of Python installed, so you might check /usr/bin for commands like python2.2 if plain python says it’s version 1.x. If your distribution uses packages, use the search tool to find prepackaged versions before trying to manually install. Try here and here for Python RPMs.
Install wxPython if you want to use the GUI version. Note that this will require the GLib and GTK+ libraries, which are probably already on your system if you have GNOME installed. (Start here or search your distribution’s package manager if you need GTK+.) You’ll want to find the wxPython package corresponding to the version of Python which you have installed. For RPM systems such as RedHat and Mandrake, you might try the following wxPython RPMs corresponding to version 2.1, version 2.2, and version 2.3 of Python. More RPMs are available at the Sourceforge site, and you can also consult the wxPython download page. Please be aware that the RPMs linked above assume that Python is installed under /usr and that the Python libs are in /usr/lib/python2.x/. If this is not the case, you will probably need to tell the installer this information.
Finally, install the source tarball for the BT client to a directory of your choice. To integrate the client with your web browser, it will be necessary to associate files of type “application/x-bittorrent” with the BitTorrent client. You will need to add a line such as the following to your /etc/mailcap file:
application/x-bittorrent; /usr/local/bin/btdownloadgui.py –responsefile %s; test=test -n “$DISPLAY”
Note that you should substitute the correct path for the location in which you installed the source tarball. If don’t have wxPython or would prefer to use one of the text-mode clients you can replace btdownloadgui.py with btdownloadcurses.py or btdownloadheadless.py. Also note there’s an error in the INSTALL.unix.txt file, which is missing the –responsefile argument.
Other web browsers may have a different way of associating a command with a MIME-Type, so you may want to try looking at the preferences or init file for details.
BitTorrent is not like other peer-to-peer applications (such as Winmx, Kazaa, Gnutella, etc.) in that it does not have its own “universe.” Put another way, BT lives on top of the Web, which means that all of the searching/listing of available files is done on the web. When you find a file you want to download, you click on it and the BitTorrent client program will run and ask you where to put it, and then start downloading.
Here is a brief list of words associated with BitTorrent and their meanings.
mod_rewrite is a module for the Apache webserver that allows apache to dynamically change the url of a site using php (or other scripting languages). It may seem like a difficult/confusing task at first, but it actually only takes a few steps on most linux distro’s .
1. Before you begin this, please make sure you make a backup copy of the original file in case you make a mistake, this way you can always go back to the original configuration - always backup before you begin doing something like this.)
2. Find the httpd.conf file (usually you will find it in a folder called conf. In Fedora you can find it at /etc/httpd/conf .)
3. Inside the httpd.conf file find and uncomment the line “LoadModule rewrite_module modules/mod_rewrite.so”
4. After you have made the changes and saved them, restart your httpd (apache) server for the changes to take affect. as root : apachectl -k restart
Test It
If apache started without any errors mod_rewrite should be enabled, so now lets verify:
1. Create a php file called “rewrite.php” with your text editor
2. Copy and paste the following code into rewrite.php
<html>
<h2 align=center>
<?
// mod_rewrite Test Page
// Dtek360 2008 dtek@dtek360.net
if($_GET['link']==1){echo”You are not using mod_rewrite”;}
elseif($_GET['link']==2){echo”Congratulations!! You are using Apache mod_rewrite”;}
else{echo”Linux Apache mod_rewrite Test Tool”;}
?>
</h2>
<hr>
<head>
<title>How To Test mod_rewrite in Apache Linux Server</title>
</head>
<body>
<p align=”center”>by <a href=”http://www.dtek360.net”>dtek360</a></p>
<p><a href=”rewrite.php?link=1″>LINK1</a> = rewrite.php?link=1</p>
<p><a href=”link2.html”>LINK2</a> = link2.html</p>
<p>How this works: both links are for this same page, except they both are different. link one is without the mod_rewrite and link2 is using mod_rewrite. Link1 show the php file, with with mod_rewrite we are mascarading the php file into a html file. you can use whatever type of extension you want, you can change it to .htm or .shtml etc… all you have to do is to make sure you also change it in the .htaccess file</p>
<p><<
</body>
</html>
3. Save rewrite.php
4. Now create a file called .htaccess with your text editor
5. Populate the following into the .htaccess file:
RewriteEngine On
RewriteBase /t1/
This requires you have the alias setup in httpd.conf “Alias /t1/ “/var/www/html/test”
RewriteRule ^link([^/]*).html$ rewrite.php?link=$1 [L]
6. Save .htaccess
7. Now upload these two file into a new directory in your site. for example: test
8. Open the rewrite.php file with your browser .
9. you should see two links, LINK1 and LINK2 Click on LINK1 and the same page will display.
10. Now click on LINK2 and the same page will display with the a mod_rewrite message. If it doesnt you either did something wrong. Check your steps. If you checked your steps, refresh your browser, and if refreshing doesn’t work, then you don’t have mod_rewrite enabled.
You can also add this code to rewrite.php to see if mod_rewrite was loaded by apache:
if ( in_array(”mod_rewrite”, apache_get_modules()) ) echo “mod rewrite on”;
NOTE
The “AllowOverride All” must be set for .htaccess to override config settings
You will pull your hair out trying to figure out why you thing it is set up properly, but the rewrite is
not working as you get http 404 pages.
You can also enable Rewrite Logging to get some useful debugging info:
in httpd.conf:
RewriteLog “/var/log/httpd/rewrite_log”
RewriteLogLevel 9
So far, we covered backing up files locally and over a network. Now let let see how to backup databases(only mysql supported - yet).
The script uses ‘mysqldump’ command to backup the data. That means that the backups are in the SQL dump format. The dumps of all the databases that are backed up are compressed and stored in the destination folder. They will be named in this format - YYYY-MM-DD.tar.gz.
This script reads a configuration file named ‘dbbackup.config’ and backups all the databases specified in that file to another location in the same system. This configuration file must be in the same folder as the perl script. The configuration file format is given below…
Data
Project_Nexty
App_activecollab
# Unwanted_DB - commented - will not be backedup
binco
binnyva
#!/usr/bin/perl
# Backups all the databases specified in the dbbackup.config file
$backup_folder = '/var/Backup/Special/Databases'; #EDIT THIS LINE
use File::Basename;
my $config_file = dirname($0) . "/dbbackup.config";
my @databases = removeComments(getFileContents($config_file));
chdir($backup_folder) or die("Cannot go to folder '$backup_folder'");
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
$year += 1900;
$mon++;
#Zero padding
$mday = '0'.$mday if ($mday<10);
$mon = '0'.$mon if ($mon<10);
my $folder = "$year-$mon-$mday";
mkdir($folder) or die("Cannot create a folder called '$folder'");
foreach my $database (@databases) {
next if ($database eq '');
chomp($database);
my $table = '';
if(index($database,' ')+1) { #Get just 1 table in the database - if there is a ' '(space) in the db name
my @parts = split(' ',$database);
$database = $parts[0];
$table = $parts[1];
}
print "Backing up $database ... ";
my $file = $database;
$file .= '_' . $table if($table ne '');
$file .= ".sql";
`mysqldump -u root $database $table > $folder/$file`;
print "Done\n";
}
print "Compressing the folder ... ";
`tar -czf $folder.tar.gz $folder/`;
print "Done\nRemoving Folder ... ";
`rm -rf $folder`;
print "Done\n\n";
sub getFileContents {
my $file = shift;
open (FILE,$file) || die("Can't open '$file': $!");
my @lines=<FILE>;
close(FILE);
return @lines;
}
sub removeComments {
my @lines = @_;
@cleaned = grep(!/^\s*#/, @lines); #Remove Comments
@cleaned = grep(!/^\s*$/, @cleaned); #Remove Empty lines
return @cleaned;
}
If you need, you can set this script as a cron job - this will make sure that you don’t have to worry about the backup.
This script will backup the specified files to another computer on your network. You can also use this to send your files to a remote server. This script compliments the last Rsync Backup script. Its possible to combine both the script together, I prefer to keep them separate.
The Setup
For this to work, you need to have a password-less login system over ssh. You should configure the remote system to accept your credentials by giving your public key to the remote server. If you are not sure how to do that, just leave a comment and I’ll make a post on how to set it up.
The configuration file is the same format as the one used in the last Rsync script. But in this case, the file name will be ‘rsyncnetworkbackup.config‘.
The Code
#!/usr/bin/perl
#The folder on the remote system that must be used to store the data
$backup_folder = ‘/home/neo/Backup’; #Final ‘/’ must NOT be there.
# The user for whom we have set up the key based login
$backup_user = ‘neo’;
# The IP address/domain name of the remote system.
$backup_server = ‘192.168.0.30′;
use File::Basename;
my $config_file = dirname($0) . “/rsyncnetworkbackup.config”;
my @all_locations = removeComments(getFileContents($config_file));
foreach my $folder_locations (@all_locations) {
my($folder,$backup_location) = split(/\s+/,$folder_locations);
print “Backing up $folder to $backup_location … “;
`rsync -avze ssh $folder $backup_user\@$backup_server:\”$backup_folder/$backup_location\”`;
print “Done\n”;
}
sub getFileContents {
my $file = shift;
my @lines;
open (FILE,$file) || die(”Can’t open ‘$file’: $!”);
@lines=;
close(FILE);
return @lines;
}
sub removeComments {
my @lines = @_;
@cleaned = grep(!/^\s*#/, @lines); #Remove Comments
@cleaned = grep(!/^\s*$/, @cleaned); #Remove Empty lines
return @cleaned;
}
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Related Posts
# Shell Script to Backup Files Locally Using Rsync
# Perl Script to Backup MySQL Databases
# Nautilus Scripts - Terminal, File Finder
There are no shortage of audio players in Linux. It has everything from command line MP3 players(mpg123) to RAM eating GUI players(like Amarok). With easily available codecs, linux supports almost all available formats.
This is the final post on a series about MP3 Players in linux. This series focuses on dedicated audio players - not video players that can handle audio as well(like mplayer). Without further ado, presenting the top 10 Linux MP3 players…
amaroK is currently the player of my choice - it rocks. Everything I ever wanted in a MP3 Player and more. It is the clear winner in this field. In my opinion, there is nothing that beats amarok even if you look at Windows and Mac MP3 players as well.
A Winamp clone. Simple and user friendly, it is very popular on linux. It does not have a large feature set - but I am going to give it second place due to its popularity.
Rhythmbox Music Player is a music player and library for tagged files, that support various music formats. It was inspired by Apple’s iTunes. Although it is designed to work well under the GNOME Desktop, I had no issues with it in KDE.
RhythmBox - Gnome Music Player
Exaile is a music player aiming to be similar to KDE’s Amarok, but for GTK+ and written in Python. It incorporates many of the cool things from Amarok (and other media players)
Exaile - Music Player for Gtk+
Audacious is not among the ’star media-players’ in Linux - so many people never try it out. But those who have tried it out like it. For the sake of the article, I installed it - and I liked it. I even considered switching from amaroK to Audacious.
Banshee is an MP3 players for Gnome. You can import, organize, play, and share your music using Banshee’s simple, powerful interface.
Banshee - Music Management and Playback for GNOME
SongBird is an MP3 player built on the XUL framework. It’s a desktop media player mashed-up with the Web.
SongBird - The Firefox of MP3 Players
An audio jukebox that supports collections of MP3, Ogg Vorbis and FLAC files. It is a part of the kdemultimedia package.
mpg123 is a fast, free, minimalist, console MPEG audio player software program for UNIX and Linux operating systems.
mpg123/mpg321 - The Command Line MP3 Players
Instead of putting the last MP3 Player here, I am going to list the MP3 software that did not make it to the list…
So, which is your favorite MP3 Player? Leave a comment…
To me, a shell script is a script that automates repetitive tasks. But that is not the ‘official’ definition. Wikipedia has this definition…
A shell script is a script written for the shell, or command line interpreter, of an operating system.
I use a definition that defines the purpose of the script - while the others prefer a definition that defines the technology used. I am not going to claim that my definition is better than the other definition - that’s pointless. Besides, even I think that the ‘other’ definition is the right one. But I will try to show you the advantages of my approach.
I like to automate things(in other words, I’m lazy). So I have a nice little collection of custom shell scripts. But there is a huge barrier to writing shell scripts - the language used. Traditionally shell scripts are written in a language provided by the shell - like bash or tcsh. That is the problem - these languages are Bad - with a capital ‘B’.
To people who are accustomed to decent languages, these shell languages will seem clunky - or even evil. But since most shell scripts are small, most people don’t mind the torture.
In bash, the control flow commands seem to be thrown in as a after thought rather than something that’s built into the language. If you don’t believe me, compare the ‘if’ loop of bash and Perl.
This code checks wether the variable ‘$value’ has the value 0 - if so it prints the message ‘No Value’
if [ $value -eq 0 ] ; then
echo "No Value"
fiThe same code in Perl…
if($value == 0) {
print "No Value";
}Of course, Perl experts will go for if(!$value) or even unless($value) - but that’s not the point. See how better the code looks in Perl. Yeah, even I am surprised to hear those words - Perl is considered by many to be an ‘ugly’ language. But when compared to shell languages, Perl is a gem(sorry about the pun - couldn’t resist).
The solution is simple - don’t use a shell language to write your shell scripts - use a high level scripting language like Perl. Or Python, Ruby, PHP, Tcl or even JavaScript.
I still use bash to write shell scripts - but if the shell script has an if condition(other than a simple argument check), I use a higher language - usually Perl.
So why am I telling you all this? Two reasons…
One, the next time you are going to write a shell script, I want you to choose a high level language rather than using bash.
The second reason is that now that my series on Linux MP3 Players are over, I am going to take a small break from desktop posts and write on more ‘linuxy’ topics. And one of those topic is Shell Scripting. So in the future posts, I am going to share some of my shell scripts with you. So when I publish a Perl script and call it a shell script, I don’t want you to get confused .
All programmers have their own customized backup solutions. I have six. Yes, six! Five to backup files and one to backup database tables. And I am not counting version control or other backup systems built into the tools I use. Anyway, in the first post of the shell scripts series, let me introduce you to my Rsync based local backup solution.
This script reads a configuration file named ‘rsyncbackup.config’ and backups all the folders specified in that file to another location in the same system. This configuration file must be in the same folder as the perl script. The configuration file format is given below…
#Notes - do NOT include the last '/' at the end of the source folders
~/Scripts
~/Documents
#################### Web files ####################
# My Sites
#Folder to backup #Folder to which it should be backuped to
/var/www/html/Sites Htdocs/
/var/www/html/Projects Htdocs/If there is just one column in a line, that folder will be backuped to “<backup folder>/<folder name>“. Let say that my backup destination folder is ‘/var/Backup/Rsync‘. So the first line, ‘~/Scripts‘ will copy the contents of ‘~/Scripts‘ to ‘/var/Backup/Rsync/Scripts‘
If a line in the configuration file has two columns, then an extra folder will be created with the name provided in the second column. For example, the line ‘/var/www/html/Sites Htdocs/‘ will create a backup of ‘/var/www/html/Sites‘ in ‘/var/Backup/Rsync/Htdocs/Sites‘
And if you have not guessed it already, all lines that begin in a # are comments and will be ignored.
There is the perl script that automates the rsync calls…
#!/usr/bin/perl
#EDIT THIS LINE
$backup_folder = '/var/Backup/Rsync'; #Final '/' must NOT be there.
use File::Basename;
my $config_file = dirname($0) . "/rsyncbackup.config";
my @all_locations = removeComments(getFileContents($config_file));
chdir($backup_folder) or die("Cannot go to folder '$backup_folder'");
foreach my $folder_locations (@all_locations) {
my($folder,$backup_location) = split(/\s+/,$folder_locations);
print "Backing up $folder to $backup_location ... ";
`rsync -a $folder $backup_folder/$backup_location`;
print "Done\n";
}
sub getFileContents {
my $file = shift;
my @lines;
if(!open (FILE,$file)) {
die("Can't open '$file': $!");
} else {
@lines=<FILE>;
close(FILE);
}
return @lines;
}
sub removeComments {
my @lines = @_;
@cleaned = grep(!/^\s*#/, @lines); #Remove Comments
@cleaned = grep(!/^\s*$/, @cleaned); #Remove Empty lines
return @cleaned;
}Execute this script using the command ‘perl RsyncBackup.pl’. In my system I have created an alias ‘bk’ for this script. I recommend that you make a similar alias if you take backups regularly(extremely recommended).
Backing up is done using rsync - so its faster than a simple ‘cp’ as only the modified and new files are copied.
The kernel summit was two months ago, and at the end of that I got one of the new 80GB solid state disks sent to me from Intel. Since then, I’ve been wanting to talk to people about it because I’m so impressed with it, but at the same time I don’t have anyone locally who is interested enough to blabber to, so since I’m testing this whole blogging thing, I might as well vent about it here.
This drive is the absolute truth.
I’ve been impressed by Intel before (Core 2), but they’ve had their share of total mistakes and idiotic screw-ups too (Itanic), but the things Intel tends to have done well are the things where they do incremental improvements. So it’s a nice thing to be able to say that they can do new things very well too. And while I often tend to get early access to technology, seldom have I looked forward to it so much, and seldom have things lived up to my expectations so well.
In fact, I can’t recall the last time that a new tech toy I got made such a dramatic difference in performance and just plain usability of a machine of mine.
So what’s so special about that Intel SSD, you ask? Sure, it gets up to 250MB/s reads and 70MB/s writes, but fancy disk arrays can certainly do as well or better. Why am I not gushing about some nice NAS box? I didn’t even put the thing into a laptop, after all, it’s actually in a 1U Slackware server, so a RAID NAS box would certainly have been a lot bigger and probably have more features.
But no, forget about the throughput figures. Others can match - or at last come close - to the throughput, but what that Intel SSD does so well is random reads and writes. You can do small random accesses to it and still get great performance, and quite frankly, that’s the whole point of not having some stupid mechanical latencies as far as I’m concerned.
And the sad part is that other SSD’s generally absolutely suck when it comes to especially random write performance. And small random writes is what you get when you update various filesystem meta-data on any normal filesystem, so it really does matter. For example, a vendor who shall remain nameless has an SSD disk out there that they were also hawking at the Kernel Summit, and while they get fine throughput (something like 50+MB/s on big contiguous writes), they benchmark a pitiful 10 (yes, that’s ten, as in “how many fingers do you have) small random writes per second. That is slower than a rotational disk.
In contrast, the Intel SSD does about 8,500 4kB random writes per second. Yeah, that’s over eight thousand IOps on random write accesses with a relevant block size, rather than some silly and unrealistic contiguous write test. That’s what I call solid-state media.
The whole thing just rocks. Everything performs well. You can put that disk in a machine, and suddenly you almost don’t even need to care whether things were in your page cache or not. Firefox starts up pretty much as snappily in the cold-cache case as it does hot-cache. You can do package installation and big untars, and you don’t even notice it, because your desktop doesn’t get laggy or anything.
So here’s the deal: right now, don’t buy any other SSD than the Intel ones, because as far as I can tell, all the other ones are pretty much inferior to the much cheaper traditional disks, unless you never do any writes at all (and turn off ‘atime’, for that matter).
So people - ignore the manufacturer write throughput numbers. They don’t mean squat. The fact that you may be able to push 50MB/s to the SSD is meaningless if that can only happen when you do big, aligned, writes.
If anybody knows of any reasonable SSDs that work as well as Intel’s, let me know.
You don’t know this, but your life is empty and missing something important. You need a woolly mammoth in the living room, and on a leash to take shopping. There will be a range of sizes to choose from, mammoths to order from miniatures for condos to 17 ft tall behemoths that will live on your ranch.
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