Fixing Choppy Video Playback (Vostro 1100 & XP)

ISSUE: Windows and VLC playback is suddenly choppy on a Dell Vostro 1100 Laptop. 

This issue arises after playing a DVD that reports errors and Windows reverts back to PIO Mode (slower) which it deems more reliable than the more common DMA mode.

SOLUTION: You may be able to simply change the setting by going to Settings-> Control Panel-> System-> Device Manager-> IDE ATA/ATAPI Controllers-> Primary IDE Channel-> Advanced Settings and checking to see if it has defaulted to PIO. Changing this back to DMA may resolve your problem however I found otherwise. If this doesn't fix the issue, right click on the Primary IDE Channel and remove it or both if more than one is listed. The system will auto reinstall them.

Reboot and attempt playing a commercial DVD. This should resolve your choppy video playback problem.

Hobbit/Xymon - Install on CentOS (coming soon)

A few notes for my future post...

After installing Xymon (Hobbit) on a CentOS system I found that the graphs didn't contain any text.  Very frustrating to say the least.  I did the following to temporarily solve my problem, but this might become permanent.

 Used the ldd tool to determine which rrdtool library was used

# ldd /usr/lib/xymon/server/bin/hobbitgraph.cgi

    linux-gate.so.1 =>  (0xffffe000)
    libpcre.so.0 => /lib/libpcre.so.0 (0xf7f5a000)
    librrd.so.2 => /usr/lib/librrd.so.2 (0xf7f10000)
    libpng12.so.0 => /usr/lib/libpng12.so.0 (0x004c4000)
    librt.so.1 => /lib/librt.so.1 (0x00b9d000)
    libc.so.6 => /lib/libc.so.6 (0x00a3b000)
    libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0x003ac000)
    libz.so.1 => /usr/lib/libz.so.1 (0x0050a000)
    libart_lgpl_2.so.2 => /usr/lib/libart_lgpl_2.so.2 (0xf7ef8000)
    libm.so.6 => /lib/libm.so.6 (0x00bc3000)
    libpthread.so.0 => /lib/libpthread.so.0 (0x00ba8000)
    /lib/ld-linux.so.2 (0x00a1c000)

Then...I did a strings and grep to see what ttf file it references

# strings /usr/lib/librrd.so.2 |grep ttf

 @/usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf
"@/usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf
@/usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf
 @/usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf
 @/usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf

File did not exist nor the directory it was referencing...need to go back and determine why this is.

Created directory as referenced above.

Grep'd for the "DejaVuSnasMono-Roman.ttf" font and didn't find it on the system.  However I did find a very similar one named "DejaVuLGCSansMono.ttf and created a symbolic link to it for a test.

# ln -s /usr/share/fonts/dejavu-lgc/DejaVuLGCSansMono.ttf ./DejaVuSansMono-Roman.ttf

Presto.  Worked like a charm.

OpenVPN - Bridging Mode

Scope:  OpenVPN 2.2.0 on CentOS 5.6

Previously I documented the install of OpenVPN on Debian in a bridged configuration.  Later I installed a similar setup on CentOS 5.6 and found that some additional steps were required.

 

As a place holder and reminder....

 

Create ifcfg-br0 file.

 

cat /etc/sysconfig/network-scripts/ifcfg-br0

DEVICE=br0
TYPE=Bridge
IPADDR=192.168.0.100
NETMASK=255.255.255.0
GATEWAY=192.168.0.1
ONBOOT=yes

 

Modify the ifcfg-eth0 file (or the interface file you are creating the bridge to)

 

cat /etc/sysconfig/network-scripts/ifcfg-eth0

 

DEVICE=eth0
TYPE=ETHER
BRIDGE=br0
ONBOOT=yes
 

Set Scripts to run at start-up.

ZenCart 1.3.9 - Template Problem

ISSUE:

After working to create a custom theme I found the default template and any new templates became unavailable through the typical method within the admin console.  I attempted to resolve the issue by re-installing and stepping through each modification systematically with no success.  This led to the manual modification of the database to choose the theme of choice.

WORK AROUND:

• Obtain the database name, database username and password.
• Create a new template being sure to include a template_info.php with the correct information.  Note the directory name.
• Enter MySQL (-p will prompt for the user password)

       # mysql -u database_username -p

•  Select database to use.

       mysql> use database_name;

• Change the default template dir.

       mysql> UPDATE database_template_select SET template_dir = 'new_template'; 

• Exit database

       mysql> \q

Template directory has now been changed and will be reflected in the admin console.

ZenCart - MySQL Database Backup & Restore (mirror really)

While there seems to be a tremendous amount of information on MYSQL and backing up databases as well as restoring them, I ran into some challenges and had to follow the steps below to mirror a database.

My goal was to simply have the ability to backup my database while going through some testing.  I also wanted to verify that once I had a working "development" environment that I could export/import into a new "production" environment.  While mysqldump should accomodate this request possibly in one simple command, I had issues and ended up using mysqldump to export and the "source" command to populate a new database.  

# mysqldump -u user_name -p database_name > database_bkup_file_name.sql

Note:  Adding the '-p' will cause mysqldump to prompt for the password for the user that you stated in "user_name".

You should theoretically then be able to use mysqldump to then populate a database as follows:

# mysqldump -u user_name -p database_name < database_bkup_file_name.sql

Based on some challenges and a desire to move forward and not necessarily become a MySQL admin, I simply created a new database, added the proper user & permissions followed by:

mysql> use new_database_name;

mysql> source name_of_database_backup_file.sql;

 
It should have been obvious that the new database was being populated but if you desire to verify, you can simply view the tables.

mysql> show tables;

While this proved handy, it does not allow you to update a database.  I will be making some incremental changes to a "dev" environment and will want to update the "prod" environment.  In order to accomplish this, I will need to drop the "prod" database and then recreate it and populate it with data.  I can see how learning to properly use the mysqlimport command may be the better answer.

OpenBSD - Compact Flash Media Installation w/Read-Only Configuration

The core "Installation Guide" (coming soon) is compliments of Lin.  He was able to compile the information from various sources and has proven it out multiple times through various installations.  

I recently had reason to install a Alix2D3 and followed his tutorial.   I strayed slightly from the instructions and will note it at the beginning along with a few oddities that I encountered. 


If you choose not to configure the CF Card as read-only be advised that Flash memory, regardless of format, is limited to a finite number of erase/write cycles for any "block," before that block can no longer be written to successfully.  In other words, the life expectancy of your system could be very short.  

I had initially setup a device in a read-write state intending to return at a later date to configure it as read-only.  This proved catastrophic as I exceeded the write cycles of the CF card in a rather short period of time.  You have been sufficiently warned...better to learn from others miss fortune.

Component List:

• VMware Fusion - MacBook Pro
• OpenBSD 4.8 ISO 
• 2G CF Card
• ALIX2D3 - PCEngines mainboard & Case
• NULL Modem Cable 
• USB -> Serial cable
• Compact Flash Card Reader

Helpful Hints based on my most recent installation:

Each time I partitioned and formatted the CF card without a reboot, I encountered write errors on the CF card and the installation failed.  If you experience this same issue, I found that partitioning followed by an immediate restart of the installation was the answer.  This may simply be a problem related to Fusion or the method I am using for installation.

To minimize the installation footprint, I did not install any "x" packages.  If you do find something missing, it is a trivial matter to add at a later date.

I opted to use a 9600 baud rate throughout instead of 19200.

While using both "screen /dev/tty.usbserial 9600" and putty under windows to console to the Alix2D3 device, I experienced times where the output to the console was clean but it wouldn't accept any input from the keyboard.  This led me on a wild goose chase for a time but I was able to determine that this happens on both a windows and Mac OSX platform.  Resetting the terminal would not resolve the issue, it required that I move the usb -> serial cable to a different port.  No reset of the device was necessary.

I also utilized another OpenBSD virtual machine to mount the CF Card after the installation to make the minor modifications necessary in fstab.  If you choose to make additional changes or symbolic links while mounted in this way, please use extreme caution as any mistake could lead to an unusable installation.

If setting up as a firewall remember the following:

• /etc/mygate
• rc.conf (pf=YES)
• sysctl.conf (ip forwarding)
• pf.conf requires syntax changes for ver. 4.7 and later. 

-----------------------------------------------

Installing OpenBSD on CompactFlash

----------------------------------------------

First you need to get a compactflash or other media installed with OpenBSD

Download latest .iso image and save it on a box with vmware or other vm technology

Create a virtual machine with no disk drives, and point the cdrom to the OpenBSD install .iso file.

Boot from cd on the vm, thus entering the OpenBSD install process.

When you get to the (I)nstall, (U)pgrade or (S)hell? prompt, connect/insert the usb device holding your intended media to the usb hub of the virtual machine.  OpenBSD should recognize the media correctly if you insert it after boot.  Otherwise you might get errors asking about the geometry of the disk.

Proceed with normal install on sd0 or other appropriate device.

Make sure you include the ramdisk kernel in the install bsd.rd or whatever.

-----------------------------------------

Booting the New OpenBSD install

-----------------------------------------

After install insert your media (compact flash) into a running OpenBSD machine.  Mount the sd0a (if that is /) partition for example and enter the /etc dir.

Create a boot file (/etc/boot.conf) with the following, unless you answered yes to the questions regarding the console output when prompted during installation:

stty com0 19200

set tty com0

Now when you boot from the new install, the serial port will be used for the console, so you can connect from another PC via a serial cable using screen thus:

sudo screen /dev/ttyS0 19200

My Mac required syntax of

screen /dev/tty.usbserial 19200

A regular boot from the new install will probably fail as your media is now the boot disk and will be referenced differently (not sd0) by the OS, while the /etc/fstab file probably still says sd0a or whatever.

In order to fix this and other problems, you actually want to boot the ramdisk first.  To do so, use the following as the boot line in the above boot.conf to begin with.

boot wd0a:/bsd.rd 

or type

wd0a:/bsd.rd

at the boot prompt

When you get to the prompt, choose "S" for shell.

Now you can work with things to prepare for a real boot.

-------------------------------------------

Get into a Sane Working Environment

-------------------------------------------

Mount your partitions so that /mnt is the root of the newly installed system, and everything is mounted correctly under that.

Next, we chroot to /mnt thus:

# /mnt/usr/sbin/chroot /mnt

Set some environmental variables thus:

# export TERM=vt220

# export HOME=/

vi should work for you now, but if not it's located at /usr/bin/vi

Update the /etc/fstab file to reflect how your OS views your install media now.

/dev/wd0a / ffs rw 1 1 

Note: that the sd0a from the usb device specified to install OpenBSD on originally has been changed to wd0a

Find out what your network interfaces are by running ifconfig

Now copy /etc/hostname.xxx to create files for your interfaces such as

/etc/hostname.dc0

/etc/hostname.vr0

/etc/hostname.vr1

or whatever they are - you can even edit them to assign IP's etc if you like.

My notes indicate the following is important in the /etc/ttys file (baud rate):

tty00   "/usr/libexec/getty std.19200"  vt220    on secure"

YOUR SYSTEM SHOULD BOOT NORMALLY NOW, AND YOU SHOULD BE ABLE TO GET TO IT FROM A SERIAL INTERFACE LIKE HYPERTERMINAL, MINICOM, OR SCREEN. (But only if you edit the /etc/boot.conf file to boot regularly, and not to the ramdisk)

To do so, remove the boot line - default is to boot normally after 5 seconds

Note: While this should be true, I found that I had to add the boot parameter to the last line of my boot.conf file in order for my system to boot without manually typing return at the >boot prompt.

---------------------------------------------------

Tweak OpenBSD to boot from read only disk

---------------------------------------------------

Edit the /etc/fstab as follows to provide a 50MB ram disk /mfs

Note: that wd0a has been changed to read only (ro)

/dev/wd0a / ffs ro,softdep 1 1

#/dev/wd0a / ffs rw,noatime 1 1

swap /mfs mfs rw,nosuid,-P=/skel,-s=102400 0 0

Make the dir for the ram disk above

# mkdir /mfs

Now, we have written in fstab that the content of /skel (-P=/skel)

Directory must be copied in /mfs at boot.

So, now, all the files will be stored in /skel. Start by making the directories:

# mkdir /skel

# mkdir /skel/dev

Now we can make the rights link, but first we make a symbolic link to
the real path:

# cd /mfs

# ln -s /skel/dev/ .

---------------------

Create the devices

---------------------

# mv /dev/ptyp* /skel/dev/

# mv /dev/ttyp* /skel/dev/

# cd /dev/

# for i in /mfs/dev/* ; do ln -s $i . ; done

# rm -rf /mfs/dev

------------------------------

Important RW Directories

------------------------------

In the / (root) dir:

# mv /root/ /skel/

# mv /tmp/ /skel/

# cd /

# ln -s /mfs/root .

# ln -s /mfs/tmp .

In the /var dir:

# mkdir /skel/var

# mv /var/backups/ /skel/var/

# mv /var/cron/ /skel/var/

# mv /var/db/ /skel/var/

# mv /var/empty/ /skel/var/

# mv /var/log/ /skel/var/

# mv /var/mail/ /skel/var/

# mv /var/msgs/ /skel/var/

# mv /var/named/ /skel/var/

# mv /var/run/ /skel/var/

# mv /var/spool /skel/var/

# mv /var/tmp/ /skel/var/

# ln -s /skel/var/ /mfs/var

# cd /var/

Note:  The next line did not work under ksh.  I had to create the symbolic links manually.

# for i in /mfs/var/* ; do ln -s $i . ; done

# rm -rf /mfs/var/

That should pretty much do it.  You will still need to boot in read-write mode to create your ssh keys and a few other things might have to be done in rw mode...

Create lock and unlock files thus

mkdir /usr/local/conf

echo "mount -o rw,noatime /dev/wd0a /" > /usr/local/conf/unlock.txt

echo "mount -o ro,softdep /dev/wd0a /" > /usr/local/conf/lock.txt

now you can lock and unlock when needed as follows:

`cat /usr/local/conf/unlock.txt`

or

`cat /usr/local/conf/lock.txt`

You might want to leave the following line in fstab, just commented out

#/dev/wd0a / ffs rw,noatime 1 1

So you can easily adjust if you need to reboot in RW mode.

----------------------------------------

Examples of what stuff should look like

----------------------------------------

# ls -lhF /var/

total 40

# ls -lhF /skel

total 16

drwxr-xr-x   2 root  wheel   2.0K Jul  9 22:16 dev/

drwx------   2 root  wheel   512B Jul  9 22:24 root/

drwxrwxrwt   2 root  wheel   512B Jul  9 22:25 tmp/

drwxr-xr-x  13 root  wheel   512B Jul  9 22:29 var/

# ls -lh /mfs/

#

drwxr-xr-x   2 root  wheel      512B Jul  9 21:01 account/

drwxrws---   2 root  wheel      512B Jul  9 21:01 audit/

drwxrwx---   2 root  authpf     512B Jul  9 21:01 authpf/

lrwxr-xr-x   1 root  wheel       16B Jul  9 22:37 backups@ -> /mfs/var/backups

drwxr-xr-x   3 root  wheel      512B Jul  1 17:54 cache/

drwxrwx---   2 root  wheel      512B Feb 23 08:26 crash/

lrwxr-xr-x   1 root  wheel       13B Jul  9 22:37 cron@ -> /mfs/var/cron

lrwxr-xr-x   1 root  wheel       11B Jul  9 22:37 db@ -> /mfs/var/db

lrwxr-xr-x   1 root  wheel       14B Jul  9 22:37 empty@ -> /mfs/var/empty

drwxrwxr-x   5 root  games      512B Feb 23 08:26 games/

lrwxr-xr-x   1 root  wheel       12B Jul  9 22:37 log@ -> /mfs/var/log

lrwxr-xr-x   1 root  wheel       13B Jul  9 22:37 mail@ -> /mfs/var/mail

lrwxr-xr-x   1 root  wheel       13B Jul  9 22:37 msgs@ -> /mfs/var/msgs

lrwxr-xr-x   1 root  wheel       14B Jul  9 22:37 named@ -> /mfs/var/named

drwxr-x---   2 root  operator   512B Jul  9 21:01 quotas/

lrwxr-xr-x   1 root  wheel       12B Jul  9 22:37 run@ -> /mfs/var/run

drwxr-xr-x   2 root  wheel      512B Jul  9 21:01 rwho/

lrwxr-xr-x   1 root  wheel       14B Jul  9 22:37 spool@ -> /mfs/var/spool

lrwxr-xr-x   1 root  wheel       12B Jul  9 22:37 tmp@ -> /mfs/var/tmp

drwxr-xr-x  10 root  daemon     512B Jul  9 21:01 www/

drwxr-xr-x   2 root  wheel      512B Jul  9 21:09 yp/

 

Pf Tips

Some basic notes and commands to aid in diagnosing PF.

pfctl -d	Disable the packet filter
pfctl -e	Enable the packet filter
pfctl -Fa -f /etc/pf.conf	Flush all (nat, filter, queue, state, info, table) rules and reload from the file /etc/pf.conf
pfctl -s rules	Report on the currently loaded filter ruleset.
pfctl -s nat	Report on the currently loaded nat ruleset.
pfctl -s state	Report on the currently running state table (very useful).
pfctl -v -n -f /etc/pf.conf	This does not actually load any rules, but allows you to check for errors in the file before you do load the ruleset. This is obviously good for testing.

pflogd logs in tcpdump binary format

To watch only packets that match a certain interface use the following: 

tcpdump -n -e -ttt -i pflog0 host 192.168.0.1

To watch packets that match a specific port:

tcpdump -n -e -ttt -i pflog0 port 443

To determine a specific rule as identified from tcpdump.  For example rule #100 below.  Note:  This is not the same as simply editing the pf.conf file and going to line #100.  PF expands rules due to macros etc...

pfctl -vvs rules|grep \@100