Installing and Configuring ZendServer Community Edition (CE) on CentOS 5 / 6

The quick and the dirty:

Download the Zend Server (DEB/RPM Installer Script) from zend.com. (An account is required).

un-pack the the tarball (tar -xzfv ZendServer-5.5.0-RepositoryInstaller-linux.tar.gz)

Run ./install_zs.sh 5.3 ce or ./install_zs.sh 5.2 ce depending on which version of PHP you want to run.

Edit your iptables (you are running iptables right?) vi /etc/sysconfig/iptables

Add in a line for the ZendServer lighthttpd server (-A INPUT -m state --state NEW -m tcp -p tcp --dport 10081 -j ACCEPT)

Restart iptables (/sbin/service iptables restart)

Visit (http://YOURSERVERHERE.com:10081/ZendServer/) in a web browser to accept the EULA and set a password.

Alternatively run (/usr/local/zend/bin/zs-setup accept-eula) and (/usr/local/zend/bin/zs-setup set-password YOURSECUREPASSWORD )

If you need to restart Zend Server run /sbin/service zend-server restart.  This will restart both apache (httpd) and the LightHTTPD Zend Server gui.

Some important notes before heading off into the wonderful world of Zend Server:
Be sure that your distribution's PHP isn't installed as well as the Zend Server, including the CLI, as it will mess with running php from the command line and who knows what else.

The php binary is located at /usr/local/zend/bin/php, which can be verified by running which php.  As such if you need to run php from cron be sure to add this to your path. (I have PATH=$PATH:$HOME/bin:/usr/local/zend/bin in my ~/.bash_profile).

If you need to modify a setting in php.ini you will find it at /usr/local/zend/etc/php.ini.  Remember to restart zend server for any changes to take effect.

Beyond those things there isn't too much difference between running zend server and running php from your distribution.

Yum 5.x Local repository and the new Continuous Release Repo

A few months back, possibly a year ago I started running my own local mirror of the CentOS YUM repository. The main benefit is speed in updating all of my servers. I also was able to setup a local repo of just tools that we use but aren't available in the Base CentOS repos. (I've since started adding the EPEL repository to servers that needed it.) For those curious I mirror the os, updates, and now the cr repos.

A few weeks ago the CentOS announce list and twitter feed introduced yet another repo the Continuous Release repo or cr for short. This new repo contains security and bug fixes from the upstream 5.7 release and I imagine will continue with further releases (5.8 & 5.9). CentOS has also promised a 6.0 Continuous Release repo, but have yet to deliver on that.


First off create the directories that will become the repositories.
mkdir -pv /Storage/yumRepo/{5,5.4,5.5/{os,updates,cr}/i386
mkdir -pv /Storage/yumRepo/local/el5/i386


So with out further ado, lets get into the guts of actually getting everything pulled down, synced and a repository created.

Below is the script I use to keep my mirror in sync with the closest mirror that offers rsync:

      1 #!/bin/sh
      2
      3 rsync="rsync -avrt --bwlimit=796"
      4
      5 mirror=rsync://centos.mirrors.tds.net/CentOS
      6
      7 verlist="5 5.5 5.6 5.7"
      8 archlist="i386"
      9 baselist="os updates cr"
     10 local=/Storage/yumRepo/centos
     11
     12 for ver in $verlist
     13 do
     14  for arch in $archlist
     15  do
     16   for base in $baselist
     17   do
     18     remote=$mirror/$ver/$base/$arch/
     19     $rsync $remote $local/$ver/$base/$arch/
     20     createrepo -v --update $local/$ver/$base/$arch
     21   done
     22  done
     23 done
     24 hardlink /Storage/yumRepo/centos

Now, lets break this script down line by line.  Line one is obvious, it tells the program loader what interpreter to use when running this file. Line three sets up the rsync command I'll be using.  In my case I need to limit the bandwidth usage to something sane, even though I run it off peak hours. Line five sets the mirror I'm running against. Line seven sets the versions of CentOS I'm interested in.  I really could trim this back to just 5 and 5.7 now, but I'm going to leave it in there for now. Line eight tells me I'm only going to sync i386 architect and not the x64 architect. I'm doing this because as of right now we only run x86. Line nine gives me which repositories in the i386 architect I'm going to mirror. Line ten sets up where on the local server I'm going to store everything.

Lines twelve through twenty three run rsync against all of the variations of repository and architect type for each version. In my case it would be twelve different syncs. If I where also running x64 architect it would double to twenty four. Line nineteen is the actual rsync command while line twenty creates the necessary repository files for yum to use.

Line twenty four is rather new to this script and requires you have the hardlink command installed (yum install hardlink). The hardlink command will run through everyfile in the directory specified and compare it to every other file in the directory.  It is looking for the same contents with the same permissions, but it can have a different filename.  If it finds a match it will hardlink one of them to the other, thus reducing the space required to store two copies. My only wish is that I had some hard stats for how much disk space this is saving me on the repository alone.


Now create the repository file for Yum.
#vi /etc/yum.repos.d/MyRepo.repo
This file contains:
[base]
name=CentOS-$releasever - Base
baseurl=repo.mydomain.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=1
enabled=1

[update]
name=CentOS-$releasever - Updates
baseurl=http://repo.mydomain.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=1
enabled=1

[CompanyName]
name=CentOS-$releasever - Local
baseurl=http://repo.mydomain.com/local/el$releasever/$basearch
enabled=1
gpgcheck=0
protect=0
enabled=0


We need to also tell Apache about these directories and how to serve them out over HTTP.
I changed the DocumentRoot to
DocumentRoot "/Storage/yumRepo"
then I changed the Default directory to

Options +Indexes +FollowSymLinks
AllowOverride All
Allow from all

Restart apache.
#service httpd restart


Populate Company Local repo with custom RPMs.
On every server we have installed Webmin. In the past this was installed either by hand or via our install script, but that had to be updated by hand with each update. So I will move the latest into our Company Local repo.
#mv /Storage/rpmDownloads/webmin-1.510.rpm /Storage/yumRepo/local/el5/i386/

You can move as many files into here as you want, including built from source RPMs that you may have made. After you move in any custom RPMs you have to update the Repository.
#createrepo -v --update /Storage/yumRepo/local/el5/i386/

ImageMagick convert -geometry weirdness

I don't know if this is really documented anywhere, but when using the ImageMagick program convert with the -geometry or -resize flags it also converts to 16bit color, at least when used against 1bit (Black and White) image.

The reason this is important to note is that using -compress Group4 will not work on these images because they aren't 1bit color images and they need to be. To work around this limitation you need to force the color depth with -monochrome. The downside to all of this is time.

Ripping an Image file from a PDF takes roughly .206 seconds for an 8.5x11 PDF with pdfimages (useful if a PDF has OCR embedded in it.)
Converting the resultant PBM file without -geometry 1700x2200! -monochrome takes roughly .194 seconds.
Converting the resultant PBM file with -geometry 1700x2200! -monochrome takes roughly 4.594 seconds. This is an increase of 10 - 10.5 % adding in the geometry.

*all of the above numbers are from one file, but testing of different files showed similar results. All tests where done at 200 DPI.

Here are some examples of the commands we are running for anyone curious.
convert ${outputTiffRoot}-000.p*m -density 200 -compress Group4 {outputTiffRoot}_200.tiff

convert ${outputTiffRoot}-000.p*m -density 300 -compress Group4 {outputTiffRoot}_200.tiff

convert ${outputTiffRoot}-000.p*m -density 200 -compress Group4 -geometry 1700x2200! -monochrome ${outputTiffRoot}_200.tiff

convert ${outputTiffRoot}-000.p*m -density 300 -compress Group4 -geometry 2550x3300! -monochrome ${outputTiffRoot}_300.tiff

Installing Acronis Backup and Recovery 10 Linux Agent on CentOS 5.4

I know it has been a while since I have posted anything. I have been busy testing out backup and recovery software. The latest one is Acronis Backup and Recovery 10 Advanced Server. The management server is very easy to setup and configure. I had some issues however while installing the Agent for Linux. But with a little research I was able to find what I needed and get everything installed.

Step number one is to make sure you have the Kernel Development package for your kernel. The easiest way to find out which version you need is to run the command "uname -r". On one server I needed the "kernel-devel" package and on another I needed the "kernel-PAE-devel" package. So if you don't have them already install the correct one for your server.

After this is installed you can install another prerequisite package Dynamic Kernel Module Support Framework or DKMS for short. I got mine off of DAG's repo at http://dag.wieers.com/rpm/packages/dkms/. Once this is downloaded install the package.

The last prerequisite is an updated SnapAPI module. Thanks to the Acronis KB I was able to find the updated package at http://kb.acronis.com/sites/default/files/content/2009/10/4371/snapapi26_modules-0.7.47-1.noarch.rpm.

Now that we have all of the packages installed we can install the Agent for Linux. The install is rather painless, except the License Key that you have to type in, by hand, every time for the trial edition. Maybe its only a pain point for me because I had to do it so many times while trying to get it installed.

TL;DR

#uname -r
#yum install kernel-devel
#wget http://dag.wieers.com/rpm/packages/dkms/dkms-2.0.17.6-1.rh9.rf.noarch.rpm
#rpm -Uhv http://dag.wieers.com/rpm/packages/dkms/dkms-2.0.17.6-1.rh9.rf.noarch.rpm
#wget http://kb.acronis.com/sites/default/files/content/2009/10/4371/snapapi26_modules-0.7.47-1.noarch.rpm
#rpm -Uhv snapapi26_modules-0.7.47-1.noarch.rpm
#./AcronisAgentLinux.i686

Mounting a LVM volume in Ubuntu (Live CD)

A while back my testing server crashed. This was no surprise to anyone as it was just a (Very) old workstation. However it was running my nagios install in a production setting. I had been meaning to move it to a proper server, but just hadn't gotten around to it. To make matters worse, I didn't back any of it up. So thankfully it was only the motherboard that failed and not the HDD.

I mounted the HDD in another PC I had sitting around and booted it using Ubuntu Live CD.

First, boot Ubuntu.

Second, install the needed tools:

$ sudo apt-get install lvm2

Third, load the modules to do our task:

$ sudo modprobe dm-mod

Fourth, scan the system for LVM volumes. Look for the volumes you want to mount. Typically this will be VolGroup00:

$ sudo vgscan

Fifth, we need to activate the volume(s):

$ sudo vgtchange -ay VolGroup00

Sixth, Look for the logical volume containing the root file system. Typically this will be LogVol00:

$ sudo lvs

Seventh, create the directory to mount the drive:

$ sudo mkdir /mnt/restore

Eighth, Mount the volume to the directory you just created.

$ sudo mount /dev/VolGroup00/LogVol00 /mnt/restore -o ro,user

Ninth, Copy your files off of the drive.

$ cp /mnt/restore/some/dir/and/path /some/dir/and/path

Tenth, Setup what ever backup means you have on the new server!

All in all this wasn't a terrible thing, it could have been much worse. I have since moved the nagios setup to a virtual machine and am backing it up nightly.

Nagios: check_http, using the --invert-regex option

Some times you want to check that something is running or working correctly and you work out tests for that. Other times you want to know when something is broken and throwing error messages. This is about the latter, a proper HTTP 200 code is great and all, but what if the page is just showing "Too Many Connections" instead of your home page? My old check_http command for this server used to look like, well, check_http. I didn't check anything about it specifically, just that it was returning a 200 code.

Today however I knew I needed something more in depth. Our database server lost its local network connection, but still was available over the public IP, which is what I test against. Once we re-directed the SQL requests to the public IP address of the server everything started working again, until we ran across "Too Many Connections". The database server kept all of the "local" connections open and thus we ate up the rest.

So, how to test for this scenario? After reading through the man pages of check_http I saw this little gem "--invert-regex Return CRITICAL if found, OK if not". This I knew was exactly what I was looking for! If it sees our error codes it will go Critical! Now to put this gem into practice. Here is where the man pages fall short. There is no explanation on HOW to use this, just that it exists. I tried the obvious to me "check_http -H hostname.com -w 3 -c 5 --invert-regex 'Some string'", but that didn't work. OK, lets try "check_http -H hostname.com -w 3 -c 5 --invert-regex='Some string'" nope that errored out with " option `--invert-regex' doesn't allow an argument".

Third times the charm right?

"check_http -H hostname.com -w 3 -c 5 -r 'Some string' --invert-regex '"

# HTTP OK HTTP/1.1 200 OK - 0.355 second response time |time=0.354966s;3.000000;5.000000;0.000000 size=12975B;;;0

Yes, as it turns out third time is the charm. So that got me thinking some more. How can I ensure that the page is rendering correctly, and if it isn't fail but in a specific way?

"check_http -H hostname.com -w 3 -c 5 -r 'Some string I want in my page' -r 'Some string I don't want to see' --invert-regex '"

You can add more than one -r to the check_http command and it will require all of them to be present for the test to pass, and if one of them fails then it will go critical! Perfect!

If you have any more insight into using the check_http command in Nagios I want to hear about it. We are always running into new failure scenarios that we didn't anticipate and I want to know about them before one of my users tells me about it.

Bash: Finding files between two dates in the current directory

Today my boss asked me for a bash command (or script) to find some files between two dates.

Thanks to Jadu Saikia over at Unstableme his post UNIX BASH scripting: Find Files between two dates, I had a starting point.

This will find all files between the two dates (20071019 & 20071121) in this case.

find . -type f -exec ls -l --time-style=full-iso {} \; | awk '{print $6,$NF}' | awk '{gsub(/-/,"",$1);print}' | awk '$1>= 20071019 && $1<= 20071121 {print $2}'

Now, if you want just PGP files you would do:

find *.pgp -type f -exec ls -l --time-style=full-iso {} \; | awk '{print $6,$NF}' | awk '{gsub(/-/,"",$1);print}' | awk '$1>= 20071019 && $1<= 20071121 {print $2}'

The second request that my boss was looking for with this is the file size, something that was being left out by awk. So we can fix that by updating the command to:

find *.pgp -type f -exec ls -lh --time-style=full-iso {} \; | awk '{print $6,$NF,$5}' | awk '{gsub(/-/,"",$1);print}' | awk '$1>= 20090624 && $1<= 20090901 {print $2,$3}'

We added in a $5 to the first awk command, and the final one had $3 added to it. Also I like human readable file sizes so I added -h to the ls command.

Ghostscript Convert PDF to TIFF

Again this is mainly for my reference, but someone may have trouble finding the solution like I did earlier today.

On Windows be sure to add "C:\Program Files\gs\gs8.64\bin" to your PATH, then run the following command.

gswin32c -dNOPAUSE -q -r300 -sDEVICE=tiffg4 -dBATCH -sOutputFile=[YOUR_OUTPUT_FILENAME.TIFF] [YOUR_INPUT_FILENAME.PDF]

Similarly on Linux you can run the command below.

gs -dNOPAUSE -q -r300 -sDEVICE=tiffg4 -dBATCH -sOutputFile=[YOUR_OUTPUT_FILENAME.TIFF] [YOUR_INPUT_FILENAME.PDF]

There are also possibilities to script this, and when you can do that you should. I haven't found the need to bring it to that point yet as I just had to do four files today, but should this come up again I will be scripting it in some fashion and posting the results here.

Thank you to StackOverflow for the solution to my problem. Also one of the other solutions to this is to use a recursive search of a directory with PowerShell to convert files.

Creating a RAID 5 Array in software on CentOS 5.3

In order to create a RAID 5 array entirely in software on Linux you need to do a few things.

First I used three Identical drives, same speed, size, make, and model. This may not be a requirement, but

it will defiantly help the process. For RAID 5 you will need at least three partitions of the same size.

I picked up a four disk internal hot-swap enclosure from Addonics (http://www.addonics.com/products/raid_system/ae4rcs35nsa.asp) and

a hot-swap capable raid card. Once I got everything physically installed in the server case I booted into CentOS 5.3

and got on the command line. The first thing you need to do is create partitions on the blank drives and set them to be

Linux raid autodetect (Hex value of fd). To do this run fdisk /dev/sdX where X is the drive(s) that you want to partition for the RAID array.

For me this was SDC, SDD, SDE but you results will vary.

fdisk /dev/sdc

n [ENTER]

e [ENTER]

4 [ENTER]

[ENTER]

[ENTER]

n [ENTER]

l [ENTER]

t [ENTER]

5 [ENTER]

fd [ENTER]

w [ENTER]

You will want to create an Extended partition so choose n for New partition. If you get stuck you can hit m to get the help menu.

After you hit n type e for Extended. Then you will have to enter a partition number, I choose 4 for all of my drives.

After that you n again and then choose l for logical partition type. Again it will ask for a partition number 1-4 are for primary and thus not an option,

so I choose 5 for all of my drives.

Once the logical partitions are created hit t to change the partition type. If you are unsure what to use hit l, but in this case we already know that we want to

use type fd for the Linux RAID auto.

Once the type has been changed you can type w to write this info to the drive and start on the next one.

fdisk /dev/sdd

n [ENTER]

e [ENTER]

4 [ENTER]

[ENTER]

[ENTER]

n [ENTER]

l [ENTER]

t [ENTER]

5 [ENTER]

fd [ENTER]

w [ENTER]

fdisk /dev/sde

n [ENTER]

e [ENTER]

4 [ENTER]

[ENTER]

[ENTER]

n [ENTER]

l [ENTER]

t [ENTER]

5 [ENTER]

fd [ENTER]

w [ENTER]

Now that we have three (the minimum) partitions for our RAID device we have to create it in CentOS. Here we will use a tool called mdadm to create the

actual RAID device in Linux.

/sbin/mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/sdc5 /dev/sdd5 /dev/sde5 [ENTER]

Once this returns back, and it should be pretty quick, you will have a RAID 5 device. To check the status of it run:

/sbin/mdadm --detail /dev/md0

/dev/md0:

Version : 00.90.03

Creation Time : Wed Jul 8 09:14:19 2009

Raid Level : raid5

Array Size : 2930271744 (2794.52 GiB 3000.60 GB)

Used Dev Size : 1465135872 (1397.26 GiB 1500.30 GB)

Raid Devices : 3

Total Devices : 3

Preferred Minor : 0

Persistence : Superblock is persistent

Update Time : Fri Jul 10 11:20:02 2009

State : clean

Active Devices : 3

Working Devices : 3

Failed Devices : 0

Spare Devices : 0

Layout : left-symmetric

Chunk Size : 64K

UUID : 53f6f95a:9e33f5ba:7ac8ef3e:0a40921a

Events : 0.2

Number Major Minor RaidDevice State

0 8 21 0 active sync /dev/sdc5

1 8 37 1 active sync /dev/sdd5

2 8 53 2 active sync /dev/sde5

Now for me after I first created the RAID device the state was listed as clean, degraded, rebuilding. There was a place for the percentage rebuilt and

/dev/sde5 was listed as spare. It took the better part of a day for the rebuild to finish, given that it was a three terabyte device I am not surprised by that.

Once the rebuild was done I had to create a Physical volume for LVM to be able to manage the RAID device.

pvcreate /dev/md0

After that I was able to use system-config-lvm to create the storage volume and format the drive.

Copy Directory Structure Only

This is a simple one liner for copying a Directory structure, and not the contents.

find * -type d -exec mkdir /new_directory/\{\} \;

Now there are a few caveots to this of course, but they are simple.

First the /new_directory/ has to exist.

Second, you have to run the command from within the directory that you want to copy the structure from.

For example, if I need to copy the structure of /Storage to /newStorage I would:

mkdir /newStorage

cd /Storage

find * -type d -exec mkdir /newStorage/\{\} \;

Failed to modify password entry for user while adding user with smbpasswd

I was trying to create a user today in samba and was getting the error "Failed to modify password entry for user [USER]".

I read over the man pages for smbpasswd and saw that I needed to add the -n switch because this user will not have a password. So again I tried to add the user with "smbpasswd -a -n [USER]" and got the same error.

A quick Google search lead me to a newb mistake on my part... I didn't have the user I was trying to add in my UNIX password file. A quick "useradd [USER]" followed by the same "smbpasswd -a -n [USER]" and I was all set.

Granted there are other reasons why this process might fail, but for me this was the reason.

mail command returns fseek Invalid argument, panic temporary file seek

Today I logged into one of our older servers, haven't logged into it for a while and saw that there was new mail (as always given the number of cron jobs running).

Below is the output of my command.

[root@server /]# mail 

"/var/spool/mail/root": 1832 messages 1777 new 1832 unread 

fseek: Invalid argument 

panic: temporary file seek

After a little bit of searching online I found two possible and simple solutions.

If you want to read the mail try using mutt instead of mail. It doesn't have a problem with the 2GB file size of the mail box that mail did.

If you don't care about the old stuff you can run:

rm -f /var/spool/mail/root

to remove the file and then

cat /dev/null > /var/spool/mail/root

to recreate a blank file.  

I ended up reading the mail I wanted and then blowing the file away.  But before I could recreate it there was already a new file with 62MB of mail in it.  

Excluding Directories from updatedb on CentOS 5

Running the updatedb command will update the slocate database.  However if you want to exclude certain directories for any reason, such as not wanting to include a huge NFS file store or something to that affect you have two options.

1) use the -e switch with a comma seperated list of directories to not index. (updatedb -e /Storage,/home)

2)edit the /etc/updatedb.conf file.

•  vi /etc/updatedb.conf
  
• find the PRUNEPATHS section and add the directories to the list seperated by spaces. (PRUNEPATHS = "/afs /media /net /sfs /tmp /udev /var/spool/cups /var/spool/squid /var/tmp /Storage /home")

Also you can read up on updatedb by reading the man pages.

man updatedb

error: can't create transaction lock on /var/lib/rpm/__db.000

I got the error message today while upgrading Webmin.  The fix for this is pretty simple:

rm -f /var/lib/rpm/__db.0*

rpm --rebuilddb

The first command clears out any of the files that will lock an RPM from running.  The second command rebuilds the RPM database.

Then I was able to install Webmin 1.470 from the RPM that I had downloaded with:

rpm -Uhv /Storage/rpmDownloads/webmin-1.470-1.noarch.rpm

memcached init.d statup scripts for CentOS 5.2.

While working to setup memcached on my CentOS servers I came across these scripts.  They are the typical startup, restart, shutdown, status scripts I am sure you are used to using.  

I found them on both http://www.dev411.com/wiki/Memcached_startup_files_for_Red_Hat_(RHEL) and http://www.vbseo.com/blogs/danny-bembibre/daemon-scripts-memcached-44/.  

Both sites have the same script contents but I feel that vbseo.com has the more complete instructions.