Disable OpenSolaris Network Auto-Magic (NWAM)

NWAM is now enabled by default, but it has some limitations (only one NIC is enabled, etc). Personally, I like to configure the network interfaces myself.

To disable Network Auto-Magic on SXCE (Solaris Express Community
Edition) or Indiana (OpenSolaris):

# svcadm disable svc:/network/physical:nwam

Custom df (diskfree) column output in Solaris using nawk

Let's say you want to combine some features of "df -h" with "df -n" to show filesystem type and some other custom modifications to the output. This is where awk/nakw/gawk/whatever come in handy:

% df -g | nawk '{if (NR % 5 == 1) printf "%-22s", $1 ; if (NR % 5 == 4) printf "%-10s", "fstype " $1 "\n"; if (NR % 5 == 2) printf "%-30s",$1/2/1024/1024 " GB"; if (NR % 5 == 2) printf "%-30s", $4/2/1024/1024 " GB free "}'

/	33.6627 GB	18.4351 GB free	fstype ufs
/devices	0 GB	0 GB free	fstype devfs
/system/contract	0 GB	0 GB free	fstype ctfs
/proc	0 GB	0 GB free	fstype proc
/etc/mnttab	0 GB	0 GB free	fstype mntfs
/etc/svc/volatile	7.88214 GB	7.8813 GB free	fstype tmpfs
/system/object	0 GB	0 GB free	fstype objfs
/lib/libc.so.1	33.6627 GB	18.4351 GB free	fstype ufs
/dev/fd	0 GB	0 GB free	fstype fd
/tmp	7.88142 GB	7.8813 GB free	fstype tmpfs
/var/run	7.88134 GB	7.8813 GB free	fstype tmpfs
/export/home	74.4858 GB	1.87458 GB free	fstype ufs
/storage	108.639 GB	66.9259 GB free	fstype nfs

You can also add a comma (,) to the separators and output > csv (you can open the comma separated values table in Excel or OpenOffice or any other Spreadsheet application) :-).

OpenBSD Web Portal server (Drupal)

Configuring an OpenBSD Web Portal server Running Drupal on chrooted Apache + MOD_SSL + PHP + MySQL or PostgreSQL

Final goal: Drupal Web portal with TinyMCE JavaScript editor, Unicode and Locales support running on OpenBSD 4.3.

1. Installing and configuring OpenBSD – read the FAQ, partition.

a. You can install OpenBSD via cdrom (install43.iso or cd43.iso for netinstall) or netboot via TFTP / BOOTP / DHCPD. Read diskless(8) for details. On Windows, you can use TFTPD32 for DHCP/TFTP.

b. Partition the disk (read the FAQ on partitioning). Example partitioning scheme:

Partition	Mount location	Filesystem	Mount options
/dev/sd0a	/	ffs	rw,softdep	1 1
/dev/sd0b	swap	swap
/dev/sd0c	Whole disk
/dev/sd0d	/tmp	ffs	rw,softdep,nodev,nosuid	1 2
/dev/sd0e	/var	ffs	rw,softdep,nodev,nosuid	1 2
/dev/sd0f	/usr	ffs	rw,softdep,nodev	1 2
/dev/sd0g	/home	ffs	rw,softdep,nodev,nosuid	1 2

c. Disable non-critical services (like ident, time, daytime, etc.) from /etc/inetd.conf. Just comment out the lines you don’t want with a #.

d. Make sure you enable Soft Updates (softdep) mounts – they increase the Filesystem performance tenfold when it comes to writing a lot of small files. This is done by adding “softdep” to mount options in /etc/fstab.

e. Add a regular user account. You can use the useradd(8) script. Make sure you add the user to the wheel group to allow su – root.

f. For added security configure „sudo” by running visudo(8). You can permit all users in the wheel group to sudo root: %wheel ALL=(ALL) NOPASSWD: SETENV: ALL

i. It’s usually best to disable root logins and use “sudo” for root access (sudo –i or su – if you need a root sheel). Edit /etc/ssh/sshd_config. You can also change the default ssh port from 22 to some random port to mitigate against brute force attacks. Keeps them from filling out your logs with junk. Consider using ssh keys also.

ii. Port 6969

iii. PermitRootLogin no

iv. Restart the OpenSSH daemon: „pkill –HUP sshd”

g. Configure your user profile to use a ftp mirror. Add the following to your ~/.profile: (or whatever shell you’re using, eg: .bashrc, .zshrc): PKG_PATH=ftp://ftp.su.se/pub/OpenBSD/4.3/packages/i386/; export PKG_PATH

h. Restart the system (to mount softdep, etc.).

i. Install some “critical” packages:

i. pkg_add -vi mc zsh screen elinks zip unzip bzip2

j. Install ports

i. cd /usr
sudo ftp ftp://ftp.su.se/pub/OpenBSD/4.3/ports.tar.gz
sudo tar zxf ports.tar.gz

k. Unpack the OpenBSD source code (src and kernel – sys) – these are required for patching OpenBSD:

i. cd /usr/src
sudo ftp ftp://ftp.su.se/pub/OpenBSD/4.3/src.tar.gz
sudo ftp ftp://ftp.su.se/pub/OpenBSD/4.3/sys.tar.gz
sudo tar zxvf src.tar.gz
sudo tar zxvf sys.tar.gz

l. Apply OpenBSD security patches. You download patches from http://www.openbsd.org/errata43.html and you apply them using the instructions in the patch headers:

i. ftp ftp://ftp.openbsd.org/pub/OpenBSD/patches/4.3.tar.gz
You can put 001_openssh.patch, 002_openssh2.patch and the following patches in /usr/src and apply them. Read the header for the patches for instructions.

% head -11 001_openssh.patch
Apply by doing:
cd /usr/src
patch -p0 < install ="="> lib
===> ssh
install -c -s -o root -g bin -m 555 ssh /usr/bin/ssh
install -c -o root -g bin -m 444 ssh.cat1 /usr/share/man/cat1/ssh.0
install -c -o root -g bin -m 444 ssh_config.cat5 /usr/share/man/cat5/ssh_config.0
/usr/share/man/cat1/slogin.0 -> /usr/share/man/cat1/ssh.0
/usr/bin/slogin -> /usr/bin/ssh
===> sshd
install -c -s -o root -g bin -m 555 sshd /usr/sbin/sshd
install -c -o root -g bin -m 444 sshd.cat8 /usr/share/man/cat8/sshd.0
install -c -o root -g bin -m 444 sshd_config.cat5 /usr/share/man/cat5/sshd_config.0
===> ssh-add
install -c -s -o root -g bin -m 555 ssh-add /usr/bin/ssh-add
install -c -o root -g bin -m 444 ssh-add.cat1 /usr/share/man/cat1/ssh-add.0
===> ssh-keygen
install -c -s -o root -g bin -m 555 ssh-keygen /usr/bin/ssh-keygen
install -c -o root -g bin -m 444 ssh-keygen.cat1 /usr/share/man/cat1/ssh-keygen.0
===> ssh-agent
install -c -s -o root -g _sshagnt -m 2555 ssh-agent /usr/bin/ssh-agent
install -c -o root -g bin -m 444 ssh-agent.cat1 /usr/share/man/cat1/ssh-agent.0
===> scp
install -c -s -o root -g bin -m 555 scp /usr/bin/scp
install -c -o root -g bin -m 444 scp.cat1 /usr/share/man/cat1/scp.0
===> sftp-server
install -c -s -o root -g bin -m 555 sftp-server /usr/libexec/sftp-server
install -c -o root -g bin -m 444 sftp-server.cat8 /usr/share/man/cat8/sftp-server.0
===> ssh-keysign
install -c -s -o root -g bin -m 4555 ssh-keysign /usr/libexec/ssh-keysign
install -c -o root -g bin -m 444 ssh-keysign.cat8 /usr/share/man/cat8/ssh-keysign.0
===> ssh-keyscan
install -c -s -o root -g bin -m 555 ssh-keyscan /usr/bin/ssh-keyscan
install -c -o root -g bin -m 444 ssh-keyscan.cat1 /usr/share/man/cat1/ssh-keyscan.0
===> sftp
install -c -s -o root -g bin -m 555 sftp /usr/bin/sftp
install -c -o root -g bin -m 444 sftp.cat1 /usr/share/man/cat1/sftp.0
===> scard
install -c -m 444 -o root -g bin Ssh.bin /usr/libdata/ssh

• 2. Restart the system to apply patches (or just the affected services by using pkill –HUP for example if you didn’t patch the kernel).

3. Installing additional OpenBSD filesets if required by say php5-gd: (if you skipped this at install). You can read the FAQ, but this is basically it:

a. % cd / && sudo ftp ftp://ftp.su.se/pub/OpenBSD/4.3/i386/xbase43.tgz
% sudo tar xzvphf xbase43.tgz

% sudo ldconfig -m /usr/X11R6/lib

4. Install PHP 5 (and various libraries for image manipulation, database access and Unicode support):

a. % sudo pkg_add -vi php5-core php5-mysql php5-curl php5-mbstring php5-gd
Ambiguous: choose package for php5-gd
0:
1: php5-gd-5.2.5
2: php5-gd-5.2.5-no_x11
Your choice: 1
parsing php5-gd-5.2.5

b. Activate PHP modules by creating the various symbolic links:

i. % sudo ln -s /var/www/conf/modules.sample/php5.conf /var/www/conf/modules

ii. % sudo ln -fs /var/www/conf/php5.sample/curl.ini /var/www/conf/php5/curl.ini

iii. % sudo ln -fs /var/www/conf/php5.sample/gd.ini /var/www/conf/php5/gd.ini

iv. % sudo ln -fs /var/www/conf/php5.sample/mbstring.ini /var/www/conf/php5/mbstring.ini

v. % sudo ln -fs /var/www/conf/php5.sample/mysql.ini /var/www/conf/php5/mysql.ini

5. Install, configure and secure the MySQL database:

a. % sudo pkg_add -vi mysql-server

b. Installing the default database

i. % sudo /usr/local/bin/mysql_install_db

c. Starting the MySQL service:

i. % sudo /usr/local/bin/mysqld_safe&
[1] 32390
% Starting mysqld daemon with databases from /var/mysql

d. Secure the installation (delete anonymous users, the test database and set a root password). PS: don’t use # in your password, there’s a bug in the script. Set that manually if you want.

i. % sudo /usr/local/bin/mysql_secure_installation

e. Tune some sysctl parameters for MySQL:

i. Edit /etc/sysctl.conf:
kern.shminfo.shmall=32768
kern.maxfiles=8192

ii. Apply the changes
% sudo sysctl kern.shminfo.shmall=32768
kern.shminfo.shmall: 8192 -> 32768
% sudo sysctl kern.maxfiles=8192
kern.maxfiles: 3580 -> 8192

iii. Add a mysql login in /etc/login.conf:
mysql:\
:openfiles-cur=1536:\
:openfiles-max=3096:\
:tc=daemon:

iv. % sudo cap_mkdb /etc/login.conf

6. Configure SSL (Secure Sockets Layer) for Apache mod_ssl (https). Generate a self signed certificate (or sign one) by reading ssl(8).

a. % sudo openssl genrsa -out /etc/ssl/private/server.key 1024
% sudo openssl req -new -key /etc/ssl/private/server.key -out /etc/ssl/private/server.csr
% sudo openssl x509 -req -days 365 -in /etc/ssl/private/server.csr -signkey /etc/ssl/private/server.key -out /etc/ssl/server.crt

b. Test SSL support (lynx is ssl enabled):
% sudo apachectl startssl
% lynx https://localhost

7. Configure the Apache webserver:

a. Edit the Apache configuration file and setup PHP and server details /var/www/conf/httpd.conf
AddType application/x-httpd-php .php
ServerAdmin cmihai@website
DirectoryIndex index.html index.php
ServerName hostname(fqdn)

b. Configure PHP:

i. Edit the PHP config /var/www/conf/php.ini
upload_max_filesize = 12M

c. Test PHP:
ed /var/www/htdocs/index.php
a

Test PHP:
.
w
q
% lynx http://localhost/index.php

d. Configure Sendmail for supporting the Apache chroot[1]
% sudo pkg_add -vi mini_sendmail-chroot
parsing mini_sendmail-chroot-1.3.6p0
mini_sendmail-chroot-1.3.6p0: complete

% sudo mkdir -p /var/www/usr/sbin/
% sudo ln /var/www/bin/mini_sendmail /var/www/usr/sbin/sendmail
% sudo cp /bin/sh /var/www/bin

8. Configure services to start at boot (Apache and MySQL):

a. % sudo ed /etc/rc.conf
httpd_flags="-DSSL"

b. % sudo ed /etc/rc.local
if [ -x /usr/local/bin/mysqld_safe ] ; then
su -c mysql root -c '/usr/local/bin/mysqld_safe >/dev/null 2>&1 &'
echo -n ' mysql'
fi
# Crearea unui link pentru socketul MySQL in chrootul Apache
mkdir -p /var/www/var/run/mysql
sleep 5
ln -f /var/run/mysql/mysql.sock /var/www/var/run/mysql/mysql.sock

c. Reboot to test changes.

9. Crate a database for Drupal and a user. Grand permissions:

a. % sudo mysql -u root -p
CREATE USER drupal IDENTIFIED BY 'password';
CREATE DATABASE drupal CHARACTER SET utf8;
GRANT ALL PRIVILEGES ON drupal.* to USER drupal@localhost IDENTIFIED BY 'password';

10.Install Drupal and modules:

a. % sudo pkg_add -vi drupal5-tinymce drupal5-link-to-content drupal5-imce drupal5-image drupal5-backup-migrate drupal5-autolocale drupal5-token drupal5-securelogin ImageMagick

11.Optionally configure .httauth for security:

a. % cd /var/www
% sudo htpasswd -c htpasswd username

Add .htaccess to /var/www/htdocs
AuthName "Nu este permis accesul"
AuthType Basic
AuthUserFile ../htpasswd
require valid-user

b. Add “Add AllowOverride All” în /var/www/conf/httpd.conf.

c. Restart Apache (apachectl stop && apachectl startssl).

You can now configure Drupal and the various modules. Be sure to setup a backup schedule. You can use the Drupal database backup and restore module.

You can also install Apache mod_security for additional security:
% sudo pkg_add -vi modsecurity-apache
% sudo /usr/local/sbin/mod_security-enable
% sudo apachectl stop && sudo apachectl startssl

Make sure you read /usr/local/share/doc/mod_security/modsecurity-manual.pdf

You should also keep an eye on your webserver. For monitoring, I recommend top(1), vmstat, (8), sysctl hw, pftop and mytop.

% sudo pkg_add -vi mytop pftop
% sudo /usr/local/sbin/pftop

To use mytop you'll need a ~/.mytop file (and set proper permissions on it). You can add something like:

prompt=1
pass=
user=drupal
db=drupal
delay=5
port=3306
socket=
batchmode=0
header=1
color=1
idle=1

% mytop


MyTOP in Action

You'll also want to setup Packet Filter. Read the PF User's Guide, pf.conf(5) and the example rulesets in /usr/share/pf/examples. Enable pf in /etc/rc.conf (pf=YES).

---

[1] Read chroot(2) ssl(8) afterboot(8), etc.

OpenBSD 4.3 has been released

OpenBSD 4.3 has been released.

• Changelist
  
• Mirror list.
• Patches
• Upgrade Guide
• FAQ
  

Convert NRG images to ISO images (nrg2iso) using dd

If you want to convert Nero "nrg" images to ISO format to mount or burn you can either use nrg2iso, or just use dd to skip the 300k header (will work just fine for DAO images):

dd if=image.nrg of=image.iso bs=4096 skip=75

Solaris 10 update 5 Released

Solaris 10 5/08 has been released.

Project Etude - The Solaris 8 Migration Assistant now free

Project Etude - that lets you run Solaris 8 Containers (Zones) is now free.
Announcement here. Solaris 9 containers will also be available.

The project has been renamed into Solaris 8 Migration Assistant.

C Programming under Tru64 UNIX

A crash course in C programming under Tru64 UNIX :-). You've got a text editor - ed(1), of course, make(1), install(1) and a C compiler - cc(1) - and you're good to go.

Don't like ED? Well, Tru64 also comes with vi and XEmacs by default, so no worries.



All you need to do now is write a Makefile:

% ed Makefile
a
CC=cc

hello: hello.o
$(CC) -o $@ $<

hello.o: hello.c
$(CC) -c -o $@ $<

clean:
rm -f hello hello.o
.
w
q

% make
cc -c -o hello.o hello.c
cc -o hello hello.c
% ls
Makefile hello hello.c
% hello
Hello, Tru64 UNIX!
% make clean
rm -f hello hello.o
% ls
Makefile hello.c

Building Git Version Control System on AIX, HP-UX and Solaris

Git is a fast version control system originally designed for the Linux kernel and written by Linus Torvalds.
Need git on AIX or HP-UX? Here's how:

HP-UX PA-RISC 2.0:

First, you're going to need a compiler (GCC), GNU make (gmake) and GNU coreutils (install). swinstall the dependency repositories first:
coreutils 6.9 coreutils
gcc 4.2.3 gcc
libgcc 4.2.3 libgcc
libiconv 1.12 libiconv
make 3.81 make
perl 5.8.8 perl
zlib 1.2.3 zlib

Untar the package and start building:

$ ./configure --with-iconv=/usr/local/bin

Edit the Makfile:

CC = gcc
AR = ar
RM = rm -f
TAR = tar
FIND = find
INSTALL = /usr/local/coreutils/bin/install

# sudo gmake NEEDS_LIBICONV=1 NO_TCLTK=1 install prefix=/usr/local

$ which git
/usr/local/bin/git
$ uname -sr
HP-UX B.11.11
$ git --version
git version 1.5.4.4


Building GIT on AIX 5.3 POWERPC:

Install dependencies and GCC, gmake, GNU coreutils (install), etc:

gcc-4.0.0-1 libgcc-4.0.0-1 libstdc++-4.0.0-1 libstdc++-devel-4.0.0-1 gcc-c++-4.0.0-1 readline-4.3-2 readline-devel-4.3-2 zlib-1.2.3-3 zlib-devel-1.2.3-3 make-3.80-1 unzip-5.51-1 flex-2.5.4a-6 bison-1.875-3 popt-1.7-2 gettext-0.10.40-6 expect-5.42.1-3 tcl-8.4.7-3 tk-8.4.7-3 coreutils-5.2.1-2

$ ./configure

vi Makefile:

CC = /opt/freeware/bin/gcc
AR = ar
RM = rm -f
TAR = /opt/freeware/bin/tar
FIND = find
INSTALL = /usr/linux/bin/install
RPMBUILD = rpmbuild
TCL_PATH = /opt/freeware/bin/tclsh
TCLTK_PATH = /opt/freeware/bin/wish

# gmake NO_MSGFMT=1 install prefix=/opt/freeware

$ uname -a
AIX aix 3 5 004518FC4C00
$ which git
/opt/freeware/bin/git
$ git --version
git version 1.5.4.4

Solaris 10:

Solaris 10 comes with gcc, gmake and GNU tools in /usr/sfw/bin, but you'll need ginstall from GNU coreutils (you can get it from Solaris Freeware).

$ ./configure

Edit the Makefile - set the path to "ar", "gcc" and GNU "install".

CC = /usr/sfw/bin/gcc
AR = /usr/ccs/bin/ar
RM = rm -f
TAR = tar
FIND = find
INSTALL = /opt/sfw/bin/install

Look for ifeq ($(uname_S),SunOS) and set INSTALL to /opt/sfw/bin/install also.

# gmake NO_TCLTK=1 NO_CURL=1 install prefix=/opt/sfw

% uname -a
SunOS ibmsolaris 5.10 Generic_127112-11 i86pc i386 i86pc

% git --version
git version 1.5.4.4

IBM z/OS - OS/390 UNIX on zSeries Mainframe Development - C89

Here's a nice quick intro to C programming on IBM mainframes :-).

ES40 - OpenSource Alpha AXP Emulator

I've already posted about other free Alpha or VAX emulators like PersonalAlpha (the free version of CHARON-AXP, also makers of CHARON-VAX) and SIMH. Now it's time for something open source, that will work on Windows and UNIX systems.

AlphaServer ES40 Emulator is a portable emulator for the HP (DEC, Compaq) AlphaServer ES40. The current version is capable of running OpenVMS with some limitations. The goal is to have a drop-in replacement for real ES40's. Emulates the Alpha AXP EV68CB processor and other devices.

Now you can run OpenVMS or Tru64 UNIX on your own personal computer.



The advantage of ES40 over PersonalAlpha is that you can emulate EV68 CPUs and a more modern system (AlphaServer ES40) and additional hardware. It's also open source, and will run on your Windows, Linux and UNIX machines. The problem is, it's no match for CHARON-AXP or PersonalAlpha in terms of performance.



You can even use ES40 to install other operating systems like BSD and Linux on Alpha.
Here's FreeBSD/alpha 6.3-RELEASE

VPNC - Open Source client for Cisco VPN Contentrator

Got an ASA, a PIX or some other VPN Concentrator (or even Juniper NetScreen)? Well, you'll run into some troubles sooner or later. The Cisco VPN Client doesn't support 64 bit Windows clients, x86 Solaris clients and is just a pain to use on Linux.

VPNC doesn't require any kernel modules. Just put the IPSec gateway IP, IPSec ID, IPSec secret and XAuth username into /etc/vpnc/default.conf and start vpnc. It should work instantly :-). No fuss, no mess.

It will work just fine on Solaris, Linux, MacOS X or BSD machines. You can even get it running on your Windows box (Cygwin libs).

Tunneling over ICMP, DNS, HTTP and HTTPS proxies

Stuck beyond a firewall, captive portal or proxy and need your ssh (or any other service)? Here's a few ways to tunnel out:

• PTunnel - Tunnel TCP using ICMP echo request and reply packets (PING), includes authentication, allows for multiple connections.
• Iodine - tunnel IPv4 data through a DNS server, allows for authentification.
• NSTX - Tunneling network packets over DNS.
  
• Corkscrew - tunneling SSH through HTTP proxies.
• httptunnel - bidirectional virtual data connection tunnelled in HTTP requests.
• gotthard - ssh through https proxy tunnel

I've already mentioned Shared Shell and such too :-).

SeamlessRDP - Seamless Remote Desktop Connection Shells for Terminal Services

SeamlessRDP is basically like VirtualBox or VMware Fusion Seamless Mode, but for Windows Applications. Or like doing ssh -X, but with Windows :-). Or Citrix or Tarantella (Sun Secure Global Desktop), etc.

It works with RDesktop/TSClientX.

Disk monitoring and tuning with dd and S.M.A.R.T. - Reallocating bad sectors and predicting disk failure

What is S.M.A.R.T.?

Modern disk drives will automagically reallocate bad sectors on the fly, as soon as they encounter some kind of R/W/ECC error. But in order for this to happen, it must first access that sector. This is why you never see surface errors on modern disks.

Modern hard drives (ATA and SATA) have S.M.A.R.T. - Self-Monitoring, Analysis, and Reporting Technology. Once you have that enabled in BIOS (assuming you have a S.M.A.R.T. capable disk and controller) you can monitor a number of disk health and performance parameters.

What you should keep an eye on is the Reallocated Sectors Count (if the drive has a problem with a R/W/ECC error it will mark the sector "Reallocated" and transfer the data to a spare area on the disk). This will result in some performance decrease, and is a sign of imminent disk failure.


Monitoring S.MA.R.T.

ATA and SATA disks:
To monitor S.M.A.R.T. data you can use HDTune on Windows or SmartMonTools (smartd, smartctl) on Darwin (Mac OSX), Linux, FreeBSD, NetBSD, OpenBSD, Solaris, OS/2, or eComStation systems. If you're up to it, you can also use SmartMonTools on Windows.

USB Enclosures:
While in most cases you should have no trouble using HDTune or SmartMonTools, some USB drive enclosures may be resilient to monitoring with S.M.A.R.T. programs and will require vendor software. In such cases, you can download vendor software to perform monitoring, like "Western Digital Data LifeGuard Diagnostics".

iPods:
You can also get S.M.A.R.T. info on your iPod. You can either configure it to act as a pass through device (regular USB media) or boot your iPod in diagnostic mode. You can check S.M.A.R.T. disk data and perform more test on your iPod. To do so, you must reset your iPod and hold REW + Select (5G) at the Apple boot menu. For other iPod models, see here (or Google Apple Diagnostic Mode your iPod Model).

Forcing the disk to remap damanged sectors

Now you should know that if you see any problems with Reallocated Sector Count, Reallocated Event Count, Seek Error Rate, Offline Uncorrectable, UDMA CRC Error Count, Multizone Error Rate, Hardware ECC Recovered values, you should consider getting a new disk. These are all signs of a failing disk. Learn more about S.M.A.R.T. attributes and their meaning here. Note that depending on vendor, there may also be enhanced or propriotary S.M.A.R.T. attributes. Read your HDD vendor documentation.

But sometimes you just need to get a bit more life out of a disk, and force the disk to reallocated damaged sectors. You can do so easily by performing a full raw disk read and write operation. For this, you can use the UNIX "dd" tool. Make sure your target disks aren't mounted (Type "mount" to list mounted disks then use "umount disk").

You can perform a disk read operation (reading the whole disk) using a syntax similar to:

# dd if=/dev/disk of=/dev/null bs=2048

You can perform a disk write operation (zero out the disk, this WILL result in data loss) using syntax similar to:

# dd if=/dev/zero of=/dev/disk bs=2048

Now you may wish to perform both a read and write at the same time, and not wipe out your disk data (zero it out). You can perform such a "disk refresh" using syntax similar to:

# dd if=/dev/disk of=/dev/disk bs=1m

This will read and rewrite the data to disk in 1MB chunks to prevent presently recoverable read errors from progressing into unrecoverable read errors.

Of course, you should read the dd manpage for your OS (on Windows you could use a dd for Windows implementation or resort to some sort of Linux or BSD LiveCD). Replace /dev/disk with your disk (make sure you're using the right disk). On Linux you can find out what disk you need to use from "dmesg" or /proc/partitions:

# cat /proc/partitions

You can also use "fdisk -l" to list partitons on your disk, see if that's the right disk

# fdisk -l /dev/hda

Do note that you need root permissions for all of this activity, so on some Linux systems you may need to use "sudo -i" to get a root shell, or precede all operations with "sudo".

While you're doing this rewrite operation, you should monitor the kernel log (dmesg). You can monitor /var/log/messages for this:

# tail -f /var/log/messages

You usually watch out for "DriveReady SeekComplete Error status=0x51 DriveStatusError error=0x04" or some other error.

You should also keep an eye on the Reallocated Sectors and other Interesting Parameters in smartctl:

# smartctl -A /dev/hda

Do this every now and then, and note the values before you've started the operation.

Once you begin the "dd" operations you can send dd a SIGINFO signal (use pkill / kill / whatever) to make it print out I/O information (progress). Some shells / TERMS also respond to Ctrl-T by sending SIGINFO.

# pkill -SIGINFO dd

Once you're done with dd and S.M.A.R.T. tools you should also perform a filesystem check (fsck / chkdsk / whatever).

Conclusions:

1. Monitor S.M.A.R.T. data with smartclt, keep an eye on Reallocs. Consider getting a new disk if you see reallocated sectors
2. Perform a disk refresh with dd in order to prevent recoverable read errors from progressing into unrecoverable errors. You don't need fancy tools like SpinRite.
3. You can use a simple Linux or BSD LiveCD to perform the disk refresh.
   
4. This is NOT a data recovery procedure. If you're doing data recovery, use something like dd_recover to a separate media.
5. This is NOT a step by step tutorial. Read your OS manpages to make sure you're not wiping out the wrong disk or something.
6. Always monitor S.M.A.R.T. parameters in order to spot disk failure before it happens.
7. Always keep backups.
   

Links and resources:

• Linux Harddisk Monitoring with SmartMonTools (smartctl)
• HDTune - S.M.A.R.T. tool for Windows
• Wikipedia S.M.A.R.T. page (good links)
  

WinDirStat - KDirStat graphical disk usage utility clone for Windows

If you're familiar with KDirStat (or even Baobab) Disk Usage Analyzers in *NIX, you'll be happy to know there's a clone for Windows (yes, WinDirStat is the clone). Makes disk cleanup so much easier.

Just grab WinDirStat from the SourceForce page, and run it. You'll get a nice graphical view of disk usage.


Anyway, if you use Linux/BSD/whatever just use Baobab (Gnome Disk Usage Analyzer - part of gnome-utils package), KDirStat part of KDE or Filelight.

You can also get Scanner if you like that Baobab / Filelight PIE chart view, get Scanner on Windows.

Latest ZFS binaries and source code for MacOS available

The latest binaries and source code of the Zettabyte Filesystem for MacOS are now available:
http://zfs.macosforge.org/

DragonFlyBSD - HAMMER Filesystem

The DragonFlyBSD HAMMER Filesystem has made progress. DragonFlyBSD 2.0 is expected shortly, so it may well be worth a look.

Using GNU screen as a terminal emulator for serial null modem connections

Don't have tip / cu / minicom / kermit / hyperterminal / securecrt / an old vt100 / whatever around or just love GNU Screen? Here's a cool tip:

Start a screen session on the serial console at 9600baud:

$ screen /dev/ttyS0 9600

Too slow and your setup can handle it? Use 115200 baud:

$ screen /dev/ttyS0 115200

So, how do you send a break? C-a B. Just use Ctrl-a ? for help.

Run ancient UNIX v5 on your Gameboy with gbaunix

Bored? Why not run UNIX 5th edition on your gameboy..

http://www.kernelthread.com/publications/gbaunix/



Double bored? Emulate the GBA :P.