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SMB Printing in Mac OSX

Most Mac users simply access network printers using LPR, but occasionally, you will need to interact with networks that are unfriendly to this method and find yourself having to use SMB printing. It’s a little inconvenient, but overall pretty easy to configure. I found some great instructions here. The method varies depending on which version of the operating system you have, but this site has directions for OS 10.2, 12.3, and 10.4, so it pretty much covers all the bases.

Quick Start Guide for Asterisk

Asterisk is a complete open source software-based IP PBX solution that runs on a variety of platforms. It supports VOIP in several protocols, and can seamlessly integrate with almost any standards-based telephony equipment using relatively inexpensive hardware.

This guide is a quick-start set of notes that should help you get the Asterisk service up and running with the web-based graphical user interface. Much of this was taken from the various README files that come with the software download, but I thought it would be nice to have the directions all in one place so that I don’t have to search for them in the future. I did this on a new RHEL 5 install. I would imagine that the same procedure should work on most Linux distributions.

Configuration and implementation of Asterisk is fairly complex and is beyond the scope of this document. I should also say this this guide does not include directions for installing and configuring other Asterisk related software that is required to integrate with telephony equipment.

Enough disclaimers… Let’s get started.

• Download the latest source package of Asterisk, untar it and CD into the newly created directory.
• Run “make“
• Run “make install“
• Run”make samples” (Doing this will overwrite any existing config files you have, so don’t do it if you are upgrading or something like that)
• Run “make config” (This creates the `/etc/rc.d/init.d/asterisk’ file so you can crontroll the

asterisk service with chkconfig and service.)

You are now done installing Asterisk. Now let’s install the GUI.

• Download the latest source package of the Asterisk GUI client, untar it and CD into the newly created directory.
• Run “make“
• Run “make install“
• Run “make samples” This installs the sample configuration files. Again, don’t do this if you are upgrading because it will overwrite your existing files.

Now let’s configure it.

You need to edit a few Asterisk configuration files to enable the GUI

1) In /etc/asterisk/http.conf:

        [general]
        enabled = yes
        enablestatic = yes
        bindaddr=xxx.xxx.xxx.xxx (The IP address of your Asterisk server)

2) In /etc/asterisk/manager.conf

        [general]
        enabled = yes
        webenabled = yes

3) Create an appropriate entry in manager.conf for the administrative user

        [admin]
        secret = YourFavoritePassword
        read = system,call,log,verbose,command,agent,config
        write = system,call,log,verbose,command,agent,config

4) Run “make checkconfig“

Look for the following lines… They will tell you how to get to your GUI.

  * GUI should be available at
  * http://xxx.xxx.xxx.xxx:8088/asterisk/static/config/cfgbasic.html

  * Before using the GUI, Please visit the install page at
  * http://xxx.xxx.xxx.xxx:8088/asterisk/static/config/setup/install.html

5) We should be all set Let’s start or restart asterisk:

Run “/sbin/service asterisk restart“

6) Lastly, grab a web browser and go to your install page. It should look something like this:

http://xxx.xxx.xxx.xxx:8088/asterisk/static/config/setup/install.html

Configure it up and have fun with your new Asterisk server.

Diebold Voting Machine Key Copied From Photo

Diebold makes electronic voting systems. In fact they make a lot of electronic voting systems! They advertise “Over 130,000 Diebold electronic voting stations are being used in locations across the United States to assist voters in exercising their most fundamental constitutional right: the right to vote.” With the 2000 and 2004 elections being shrouded in suspicion of voter fraud, you would think that Diebold would make every effort to ensure the security of their product. They have not.

The guys at Princeton have put together a video that shows just how insecure these systems really are. Aside from the multiple logical attacks that work against them, the ways to defeat the physical security are countless. They seem to use a “wafer-tumbler” type lock that can be easily picked in under 5 seconds. Don’t know how to pick locks? No problem. Just unscrew the bottom and you have access!

As if all this was not disturbing enough, Diebold had put a picture of the master key to these systems up on their online store and Ross Kinard of SploitCast used it to create a working key of his own. While this may seem difficult, it is not. Using the image, one can determine which key blank to use fairly easily. This is because there are really not that many key blanks in use; especially for “wafer-tumbler” type locks. Once the key blank is determined, all that is left is to figure out how deep make the cuts. This can be quickly determined by referencing the photo that was so kindly provided by Diebold on their online store. Granted, there are a few more details to be aware of, but anyone who has invested much time in learning how to defeat locks should have little trouble in figuring them out.

Ross writes:

I bought three blank keys from Ace. Then a drill vise and three cabinet locks that used a different type of key from Lowes. I hoped that the spacing and depths on the cabinet locks’ keys would be similar to those on the voting machine key. With some files I had I then made three keys to look like the key in the picture.

He then sent the keys to J. Alex Halderman at Freedom To Tinker.com who quickly confirmed that two of the three keys would, indeed, open the door to the memory card on the Diebold system. This video shows the key Ross made opening the voting machine used in the Princeton study:

Didbold has finally removed the picture of the key from their website, but it would seem that it’s too little too late. The picture is out there along with more than 130,000 voting machines on which a key made from it will work. It looks like this is one company that has some explaining to do!

Horde / IMP on RHEL 4 From RPM HOWTO

Whenever you go to install applications and services on registered RHEL servers, it’s always nice to use the RPMs because up2date will keep everything current for you. Managing upgrades gets a whole lot easier when you can bring your system up to current with one simple command. Because of this, I decided that I would try to use as many RPMs as I could when I set up our latest Horde / IMP installation.

Unfortunately, RedHat does not supply RPMs for the Horde applications, but luckily CentOS does. You should be able to download them from here. Get the latest version, which at the time of this writing was horde-3.1.3-1 and imp-h3-4.1.3-1.

Don’t install them yet though because Horde and IMP have always had a lot of dependancies which must be installed and enabled first. Installing the following RPMs should take care of them.

• mysql-4.1.20-1.RHEL4.1.i386.rpm
• mysqlclient10-3.23.58-4.RHEL4.1.i386.rpm
• mysqlclient10-devel-3.23.58-4.RHEL4.1.i386.rpm
• mysql-devel-4.1.20-1.RHEL4.1.i386.rpm
• mysql-server-4.1.20-1.RHEL4.1.i386.rpm
• perl-DBD-MySQL-2.9004-3.1.i386.rpm
• php-4.3.9-3.15.i386.rpm
• php-devel-4.3.9-3.15.i386.rpm
• php-domxml-4.3.9-3.15.i386.rpm
• php-imap-4.3.9-3.15.i386.rpm
• php-ldap-4.3.9-3.15.i386.rpm
• php-mysql-4.3.9-3.15.i386.rpm
• php-pear-4.3.9-3.15.i386.rpm

Assuming you will want up2date to handle upgrades of these packages, it is very important that you either use “up2date” to install them, or download them from correct channel at the RedHat website. You could also simply get them from the CD distribution that you used to install the system itself.

Once PEAR is installed, you will have to upgrade it, and install the PEAR::Log module.

[root@server]# pear upgrade -a PEAR-1.3.6
[root@server]# pear upgrade PEAR

Ok, now let’s make sure the web server is configured to start when the system comes up:

[root@server /]# /sbin/chkconfig –list httpd

You should see this:

httpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off

But if you see 5:off, simply run:

[root@server /]# /sbin/chkconfig httpd on

Now we enable and start up our new MySQL database server:

[root@server /]# /sbin/chkconfig mysqld on
[root@server /]# /sbin/service mysqld start

And we’re ready to install Horde and IMP. Install the following RPM’s, which will put everything in /usr/share/horde and creates a file called horde.conf in /etc/httpd/conf.d/

• horde-3.1.3-1.c4.noarch.rpm
• imp-h3-4.1.3-1.c4.noarch.rpm

This will install the HORDE and IMP packages in /usr/share, and /usr/share/horde respectively.

Finally, we start or restart apache:

[root@server /]# /sbin/service httpd start

Grab a browser and go to the following URL to proceed with the Horde and IMP configuration.

http://server.example.com/horde/

Installing OpenGroupWare 1.1.5 on RHEL 3

OpenGroupWare is an open source groupware package intended as an alternative to proprietary applications such as Exchange and PostPath. It is fairly robust in its feature set, and even integrates well with MS Outlook.

Its strongest points, in my opinion are that it does not depend in any way on Active Directory, and that it integrates well with open source standards like Open LDAP and University of Washington IMAP. Its downsides are that the documentation is sparse and scattered, that is is backed with PostgreSQL rather than MySQL, and that the package is bundled into a TON of RPM's.

I have not tried installing it from source, though I suspect that it would not be much more work than using the RPM's. Anyhow, if you want to install it for yourself, here are some quick scripts to help you, as well as some quick cookbook instructions. I installed it on RHEL 3 Workstation, though I suspect that it would work most Linux distributions.

The first thing we have to do is install the foundation for OpenGroupWare From the RHEL CD's or Website:

Install apache
Install PostgreSQL
Install PostgreSQL-devel
Install php
Install php_PostgreSQL

Next, run the following commands to get the database and webserver started:

# /sbin/chkconfig httpd on
# /sbin/chkconfig postgresql on
# /sbin/service postgresql start
# /sbin/service httpd start

Sendmail should already be installed and running, but if not, you will have to install it as well.

OK, so I said before that there are a TON of RPM's that you will have to install. These can be found at the OpenGroupWare website. Get them however you want, but if you have "wget" installed, you can use my script to fetch everything you need. You can omit the "devel" packages if you don't want to install the source code.

Ok, so now we have a directory filled up wit RPM's. Many of these have a lot of dependancies, so the order of install is important. The script below has them in the correct order, so you can either use it as a reference to install them yourself, or just save the script in the directory that has all your RPM's and run it. Your choice.

Some things to note about the install.

These all have to be done on one line or "rpm" will complain that it can's resolve dependancies:
rpm -Uvh ogo-webui-app-1.1.5-r1717.0.i386.rpm ogo-theme-default-1.1.5-r1717.0.i386.rpm ogo-webui-resource-en-1.1.5-r1717.0.i386.rpm ogo-webui-resource-de-1.1.5-r1717.0.i386.rpm

ogo-database-setup-1.1.5-0.i386.rpm sets up your PostgreSQL database and database user for you. The output should look something like this:

Preparing...                     ########################################### [100%]
1:ogo-database-setup             ########################################### [100%]
PostgreSQL seems to be already initialized
and I can see it running:
PIDS used: 3456 3458 3459
We're on PostgreSQL 7 (7.4)
checking /var/lib/pgsql/data/postgresql.conf
need to patch /var/lib/pgsql/data/postgresql.conf for 7.4
backup current one to /var/lib/pgsql/data/postgresql.conf.20061213-153319
checking /var/lib/pgsql/data/pg_hba.conf
need to patch /var/lib/pgsql/data/pg_hba.conf for 7.4
backup current one to /var/lib/pgsql/data/pg_hba.conf.20061213-153319
The changes we've made require that we restart PostgreSQL...
Stopping postgresql service:    [  OK  ]
Starting postgresql service:      [  OK  ]
OK! PostgreSQL runs again: (3909 3911 3912)
creating database user: OGo
creating the database itself: OGo
we've successfully created both the user OGo and the raw database OGo
we'll now fill the database with the scheme itself
checking the logfile created during scheme rollin...
/tmp/database_setup_psql.sh.20061213-153319.log
removing log - not needed anymore

OK... Now everything is installed, and if you run the following command:

# /sbin/chkconfig --list | grep ogo

You should see the following output:

ogo-zidestore   0:off   1:off   2:on    3:on    4:on    5:on    6:off
ogo-webui       0:off   1:off   2:on    3:on    4:on    5:on    6:off
ogo-xmlrpcd     0:off   1:off   2:on    3:on    4:on    5:on    6:off
ogo-nhsd        0:off   1:off   2:on    3:on    4:on    5:on    6:off

Now, let's fire up these services:


# /sbin/service ogo-zidestore start
# /sbin/service ogo-webui start
# /sbin/service ogo-xmlrpcd start
# /sbin/service ogo-nhsd start

Everything should be up and running now, so you can grab a web browser and go to the following RUL:

http://server.domain.com/OpenGroupware

You will be logged in as the root user, so make sure to change the password.

If you are using this system as a stand-alone server, you are pretty much all set. We needed to authenticate it against our central LDAP, and point it towards our IMAP server though, so I added the following lines to "/var/lib/opengroupware.org/.libFoundation/DefaultsNSGlobalDomain.plist":


LSAuthLDAPServer = "ldapserver.domain.com";
LSAuthLDAPServerRoot = "dc=mydomain,dc=com";
imap_host = "imapserver.domain.com";
UseSkyrixLoginForImap = YES;


Make sure to put these lines at the end of the file, but before the closing braces.

The file should look something like this:

###### SNIP #######
{
"skyrix_id" = "server.domain.com";
LSConnectionDictionary = {
  databaseName = OGo;
  hostName = "127.0.0.1";
  password = "";
  port = 5432;
  userName = OGo;
};
  LSNewsImagesPath = "/var/lib/opengroupware.org/news";
  LSNewsImagesUrl = "/ArticleImages";
  Languages = (
  English
);
  TimeZoneName = GMT;
  WOHttpAllowHost = (
  localhost,
  "127.0.0.1",
  "localhost.localdomain"
);
  LSAuthLDAPServer = "ldapserver.domain.com";
  LSAuthLDAPServerRoot = "dc=domain,dc=com";
  imap_host = "imapserver.domain.com";
  UseSkyrixLoginForImap = YES;
}
###### /SNIP #######

Since the system won't let you authenticate the "root" user against the local database if your are using LDAP, you have to create a root user on your central LDAP.

Create an LDIF file called root.ldif like so:

###### SNIP #######
dn: uid=root,ou=People,dc=mydomain,dc=com
objectClass: organizationalPerson
objectClass: top
objectClass: posixAccount
objectClass: shadowAccount
uid: root
uidNumber: 0
gidNumber: 0
sn: Root
cn: Root
homeDirectory: /root
loginShell: /bin/bash
gecos: Root
###### /SNIP #######

Finally, run the following command to add the root user:


ldapadd -x -D "cn=Manager,dc=mydomain,dc=com" -W -f root.ldif"


You should now be authenticating against your central LDAP server. Have fun!

Setting Up The Automounter Service on RHEL

Mounting filesystems in RHEL is pretty straightforward and easy. Occasionally, however, you will not want the filesystem to remain mounted all the time, but rather to automatically mount for a set period of time only when it is needed. Because of networking overhead, and the general unreliability of networks, NFS mounts are a good example of when this can be especially useful.

In order to manage the automatic mounting and unmounting of filesystems on RHEL, we use the Automounter service. Here is how.

First, The main configuration file is "/etc/auto.master". It should look something like this:

#
# $Id: auto.master,v 1.3 2003/09/29 08:22:35 raven Exp $
#
# Sample auto.master file
# This is an automounter map and it has the following format
# key [ -mount-options-separated-by-comma ] location
# For details of the format look at autofs(5).
#/misc  /etc/auto.misc --timeout=60
#/misc  /etc/auto.misc
#/net   /etc/auto.net

Let's assume that we want to set up an NFS mount on "/misc/backups". We would first create an entry in this file that looks something like this:

/misc   /etc/auto.misc --timeout=120

This tells the autofs service that we want to use it to manage mounts from within "/misc", that the configuration file is "/etc/auto.misc", and that it should disconnect after 2 minuets of inactivity.

Now, let's edit the "/etc/auto.misc" file. The file has three columns: the mount point from within the /misc directory, the options for mounting the filesystem, and the filesystem to be mounted. It also includes the remote server's name since we are using NFS. It should look something like this when you are done:

#
# $Id: auto.misc,v 1.2 2003/09/29 08:22:35 raven Exp $
#
# This is an automounter map and it has the following format
# key [ -mount-options-separated-by-comma ] location
# Details may be found in the autofs(5) manpage

cd              -fstype=iso9660,ro,nosuid,nodev :/dev/cdrom
backups         -rw,soft,intr remoteservername:/path/to/nfs/export

# the following entries are samples to pique your imagination
#linux          -ro,soft,intr           ftp.example.org:/pub/linux
#boot           -fstype=ext2            :/dev/hda1
#floppy         -fstype=auto            :/dev/fd0
#floppy         -fstype=ext2            :/dev/fd0
#e2floppy       -fstype=ext2            :/dev/fd0
#jaz            -fstype=ext2            :/dev/sdc1
#removable      -fstype=ext2            :/dev/hdd

Next, we create the directory for the mount point in /misc:

# mkdir /misc/backups

And finally we restart the autofs service:

# service autofs restart

That should pretty much do it. If you don't have autofs configured to start up, you can use chkconfig to enable it. "/misc/backups" will now be mounted whenever a user or process attempts to access data on it, and it will be automatically disconnected after 120 seconds of inactivity. Last, but not least, you can always confirm that it is running with the "service" command:

# service autofs status

As always, change the details to match your own requirements.

Using Sort to List Directories by Size

If you manage a UNIX system with a large number of directories that vary in size, chances are that you've needed to figure out which ones are using up the most disk space. Of course if the directories are user accounts, the best way to do this is to enable quotas and use the "repquota" command. If you just have a bunch of directories, however, you can easily figure out which ones are largest by giving the correct arguments to "du" and "sort". Here is how:

du -sk * | sort +0nr

This will display the size of all directories and sort them from largest to smallest. If you want to sort them from smallest to largest, simply remove the "r".

du -sk * | sort +0n

If you have nested directories, you will need to incorporate foreach to recurse through and get all the directory names.

Taking Disk Cylinders From Swap on Solaris 8

Kids... DO NOT TRY THIS AT HOME! If this is not done exactly right, you will render your system unbootable and corrupt your data. That being said, under some circumstances you can take some space from your swap partition and add it to an unused one without initializing your entire disk. This is particularly useful if you decide you want to use DiskSuite to mirror your system disk, but have not allocated the 100MB partition that is needed to hold the state databases. As always, BACK EVERYTHING UP FIRST. Better yet, make two backups and store them on two different systems. This is a risky procedure, and you don't want to lose any data!

You can also use my instructions for copying a Solaris boot drive to a disk with a different partition layout as a safer alternative.

The first thing you need to do is figure out if your disk layout will allow for this procedure. Usually the swap partition is the second one on the disk, making it partition number 1 (Partition number 0 is root). If partition number 1 is swap on your system, and partition number 3 or 4 are unused, you are in good shape, and this should work. To figure this out, you should do something like this:

# format
Select the boot disk - usually disk 0
Specify disk (enter its number): 0
format> partition
format> print
This will show you the current disk layout.

Current partition table (original):
Total disk cylinders available: 24620 + 2 (reserved cylinders)

Part      Tag    Flag     Cylinders         Size            Blocks
  0       root    wm       0 -   725        1.00GB    (726/0/0)    2097414
  1       swap    wu     726 -  9436       11.90GB    (8635/0/0)  24946515
  2     backup    wm       0 - 24619       33.92GB    (24620/0/0) 71127180
  3 unassigned    wm       0                0         (0/0/0)            0
  4 unassigned    wm       0                0         (0/0/0)            0
  5        usr    wm    9437 - 10888        2.00GB    (1452/0/0)   4194828
  6        var    wm   10889 - 18148       10.00GB    (7260/0/0)  20974140
  7 unassigned    wm   18149 - 24619        8.91GB    (6471/0/0)  18694719

Here we see that partitions 3 and 4 are unused and directly after partition 1, so we can take some space from swap and assign it to one of these. Partition 2 is, of course the entire disk. I have not tried it, so I don't know if you could assign non-sequential cylinders to a partition that is not directly after swap.

So to take some space from partition 1 and add it to partition 3, the first thing we have to do is disable swap, so the format utility will let us change it.

Comment out the following lines in your /etc/vfstab file and reboot the system.

#/dev/dsk/c1t0d0s1         -       -               swap    -       no      -
#swap    -       /tmp    tmpfs   -       yes     -

This will bring the system up without swap enabled. You can now edit the disk label. Remember that our cylinders need to be sequential, so always work in cylinders when using the format utility.

Re-enter the format utility, select your system disk and view the partition table:

# format
Select the boot disk - usually disk 0
Specify disk (enter its number): 0
format> partition
format> print
Again we wee that partitions 3 and 4 are unused.

Current partition table (original):
Total disk cylinders available: 24620 + 2 (reserved cylinders)

Part      Tag    Flag     Cylinders         Size            Blocks
  0       root    wm       0 -   725        1.00GB    (726/0/0)    2097414
  1       swap    wu     726 -  9436       11.90GB    (8635/0/0)  24946515
  2     backup    wm       0 - 24619       33.92GB    (24620/0/0) 71127180
  3 unassigned    wm       0                0         (0/0/0)            0
  4 unassigned    wm       0                0         (0/0/0)            0
  5        usr    wm    9437 - 10888        2.00GB    (1452/0/0)   4194828
  6        var    wm   10889 - 18148       10.00GB    (7260/0/0)  20974140
  7 unassigned    wm   18149 - 24619        8.91GB    (6471/0/0)  18694719

The first thing we need to do is take some cylinders away from partition 1. In this example, we are looking to make partition 3 roughly 100MB, so we need to take about 75 cylinders from partition 1 so that we can add it to partition 3. Parititon 1 ends at cylinder 9436, so we need to subtract 75 from that number. 9436 - 75 = 9361, so that is the new ending cylinder for partition 1. We then subtract the beginning cylinder (726) from that number to give us the new total number of cylinders for partition 1. 9361 - 726 = 8635, so this is the number we enter when format asks for the size of the partition. Like so:

partition> 1
Part      Tag    Flag     Cylinders         Size            Blocks
  1       swap    wu     726 -  9360       11.90GB    (8635/0/0)  24946515

Enter partition id tag[swap]:
Enter partition permission flags[wu]:
Enter new starting cyl[726]:
Enter partition size[24946615b, 9436c, 12880.92mb, 12.00gb]: 8635c
partition>

Now we have to add these 75 cylinders to partition 3.

partition> 3
Part      Tag    Flag     Cylinders         Size            Blocks
  3 unassigned    wm       0                0          (0/0/0)            0

Enter partition id tag[unassigned]:
Enter partition permission flags[wm]:
Enter new starting cyl[0]:9361
Enter partition size[0b, 0c, 0.00mb, 0.00gb]:75c
partition>

Print out the new partition table to make sure everything lines up correctly:

partition> print
Current partition table (original):
Total disk cylinders available: 24620 + 2 (reserved cylinders)

Part      Tag    Flag     Cylinders         Size            Blocks
  0       root    wm       0 -   725        1.00GB    (726/0/0)    2097414
  1       swap    wu     726 -  9360       11.90GB    (8635/0/0)  24946515
  2     backup    wm       0 - 24619       33.92GB    (24620/0/0) 71127180
  3 unassigned    wm    9361 -  9436      107.21MB    (76/0/0)      219564
  4 unassigned    wm       0                0         (0/0/0)            0
  5        usr    wm    9437 - 10888        2.00GB    (1452/0/0)   4194828
  6        var    wm   10889 - 18148       10.00GB    (7260/0/0)  20974140
  7 unassigned    wm   18149 - 24619        8.91GB    (6471/0/0)  18694719

Partition 1 ends at cylinder 9360, and partition 3 picks right up at cylinder 9361. Partition 3 ends at cylinder 9436, and partition 5 begins at cylinder 9437. Partition 4, of course, remains unused. Since none of the cylinders overlap, we can go ahead and write the disk label out. DO NOT DO THIS if you have any doubt at all about what you have just done. By writing out the disk label, you could corrupt the data on your formated filesystems if any cylinders overlap into them. The format utility is usually pretty smart about keeping you from making mistakes, but be very careful anyway! You don't want to end up with scrambled eggs on a disk that has valuable data on it.

partition> label
This writes out the disk label, so you can now exit the format utility and re-enable swap in your /etc/vfstab file. Simply uncomment out the following two lines and reboot the system.

/dev/dsk/c1t0d0s1         -       -               swap    -       no      -
swap    -       /tmp    tmpfs   -       yes     -

Reboot your system, and if all goes well, it will come up, and you will see that partition 3 will have a little over 100MB on it. Usually people want to do this so they can store the DiskSuite meta database on the newly created partition. If this is the case for you, you can now move on to mirroring the system disk.

Controlling Services With chkconfig

Many system 5 UNIX variants use scripts in the /etc/rcN.d/ directories to control which services should be started in the various runlevels. If, for instance, you wanted the secure shell daemon to run in runlevel 4, you would put a script named something like "S55sshd" in "/etc/rc4.d". This script would usually accept the "start" "stop" and "restart" arguments, as well as the commands to perform these functions. When the system came up, it would execute "/etc/rc4.d/S55sshd start" when it transitioned into runlevel 4. On the way down, it would execute "/etc/rc4.d/S55sshd stop" as the system passed from runlevel 4 to runlevel 3. If you had made some changes to the sshd configuration file, and wanted to restart the service, you could manually execute "/etc/rc3.d/sshd restart" to kill and then restart the daemon.

Since this model involved having multiple copies of the same script in many different directories, Linux and others have adopted the standard of putting all service control scripts in "/etc/init.d/", and using symbolic links to these scripts in the various "/etc/rcN.d/" directories. This allowed for the SGI IRIX innovation of the "chkconfig" command, which is command line tool that manages the symbolic links for you.

How to use "chkconfig" in Red Hat Enterprise Linux:

First, all your service control scripts need to be in the "/etc/init.d/" directory. They should reflect the name of the service they control. In our example, the file is named /etc/init.d/sshd".

Secondly, they have a tag at the head of the script that looks something like this so that "chkconfig" understands that it can controll it:

# Basic support for IRIX style chkconfig
###
# chkconfig: 2345 55 25
# description: Manages the services you are controlling with the chkconfig command
###

The first set of numbers "2345" is are the default runlevels for the service, and "55" and "25" represent the name of the "S" and "K" symbolic links, and the order in which the service will be started and stopped in the respective runlevel. You will need to change these last two numbers, making them unique.

Once these requirements are met, using the command is fairly simple. When we go into /etc/rc3.d, we see a file called "S55sshd".

[root@calvin rc2.d]# cd /etc/rc3.d
[root@calvin rc2.d]# ls -al S55sshd
lrwxrwxrwx 1 root root 14 Nov 15 15:10 S55sshd -> ../init.d/sshd

We see this file is a symbolic link to "../init.d/sshd". Let's run the "chkconfig" command to turn sshd off.

[root@calvin init.d]# /sbin/chkconfig sshd off
[root@calvin init.d]# /sbin/chkconfig --list sshd
sshd 0:off 1:off 2:off 3:off 4:off 5:off 6:off

chkconfig --list sshd confirms that sshd has been disabled in all runlevels, and the symbolic link has been removed from all "/etc/rcN.d/" directories.

Let's turn sshd back on:

[root@calvin init.d]# /sbin/chkconfig sshd on
[root@calvin rc2.d]# /sbin/chkconfig --list sshd
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off

chkconfig --list sshd confirms that sshd has now been enabled in runlevels 2, 3, 4 and 5, and we see s symbolic link to "/etc/init.d/sshd" named "S55sshd" in "/etc/rc2.d/", "/etc/rc3.d/", "/etc/rc4.d/" and "/etc/rc5.d/".

Let's imagine now that we only want sshd to be enabled in runlevel 5. We run the following command to accomplish this:

[root@calvin rc2.d]# /sbin/chkconfig sshd --level 234 off
cd /etc/[root@calvin rc2.d]# /sbin/chkconfig --list sshd
sshd 0:off 1:off 2:off 3:off 4:off 5:on 6:off

chkconfig --list sshd confirms that sshd has been disabled in all runlevels except 5, and the "S55sshd" has been removed from "/etc/rc2.d/", "/etc/rc3.d/" and "/etc/rc4.d/".

There is, of course, more to it, but this should get you well on your way to happily managing your system services with "chkconfig".

Making RHEL 3 See Multiple LUNS

For some reason RHEL 3 comes out of the box configured to see only the first Lun on a SCSI channel. This is usually not a problem, as the first Lun is all you care about, but in some instances, you will need to configure the SCSI module to see multiple Luns.

In this case we are using an Adaptec DuraStor 6200S, which is set up to present the RAID controller as Lun 00, and the actual RAID array as Lun 01. Without any modifications to the system, we plug in in, and after a reboot check /proc/scsi/scsi. We can see the RAID controller, but since we can only see the first Lun on the channel, we never get to the array:

Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: Adaptec Model: DuraStor 6200S Rev: V100
Type: Processor ANSI SCSI revision: 03

The actual array would show up as "Channel: 00 Id: 00 Lun: 01", but it's not there. To resolve this, we have to first edit "/etc/modules.conf" and add the following line:

options scsi_mod max_scsi_luns=128 scsi_allow_ghost_devices=1

In our case, modules.conf looks like this after the modification:

alias eth0 e1000
alias eth1 e1000
alias scsi_hostadapter megaraid2
alias usb-controller usb-uhci
alias usb-controller1 ehci-hcd
alias scsi_hostadapter1 aic7xxx
options scsi_mod max_scsi_luns=128 scsi_allow_ghost_devices=1

Next we have to build a new initrd image. This is done with the "mkinitrd" command.

WARNING: MAKE DARN SURE you build this against the right kernel (the kernel you want to use). If you are going to replace your current initrd image with the new one, you should make a back-up copy first. The -f option will force or overwrite the current initrd image file.

cp /boot/initrd-2.4.21-47.ELsmp.img /boot/initrd-2.4.21-47.ELsmp.img.bak
mkinitrd -f -v /boot/initrd-2.4.21-47.ELsmp.img 2.4.21-47.ELsmp

Once this is done, you can reboot your machine, and check "/proc/scsi/scsi" to see confirm that it sees the second Lun. You should see something like this:

Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: Adaptec Model: DuraStor 6200S Rev: V100
Type: Processor ANSI SCSI revision: 03

Host: scsi2 Channel: 00 Id: 00 Lun: 01
Vendor: Adaptec Model: DuraStor 6200S Rev: V100
Type: Direct-Access ANSI SCSI revision: 03

Hat Tip: Alan Baker for help figuring this out.
UPDATE: RHEL 4 doest not have this problem.

REL 3 Direct Connect to EonStor A12F-G2221

This summer we have been migrating a bunch of data to our shiny new InfoTrend EonStor A12F-G2221. With 1G battery backed cache, it's a screaming box of disk, and it looks cool to boot. There is a gotcha though if you want to direct connect it to QLogic QLA2340 card on a REL 3 server. Here is what you have to do.

First, get the new driver from QLogic, or install the one that came on CD with the HBA. The one that Red Hat packages is always old and useless, and one that QLogic provides is better anyways because the installer rebuilds the rdimage for you. Once you get the package just "cd" into the "qlafc-linux-X.XX.XX-X-install" and run "qlinstall". This will install it all for you, so let it do it's thing, and reboot the system when it's done.

Now, go into the management console for your EonStor A12F-G2221. For the most part, the system defaults should work, but InfoTrend sets the default Fibre Connection to "Loop Only". This is fine if you are dealing with a san, but since we are trying to do a direct connect, we have to change it to either "Auto" or "Direct Connect". I suggest "Auto", since that way you can have the other port connected to a loop if you want.

That should be all you have to do. You will have to reboot the controller for the change to take effect, so make sure you do this during a scheduled downtime if you have the disk in production.

Changing Linux Mount Points

If you're familiar with UNIX, you know that changing mount points is really pretty easy. All you have to do is go into "/etc/fstab", "/etc/vfstab" (or whatever your flavor of UNIX happens to call its filesystem table) and change the mount director