Find Files

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To look for files older than a day:

find . -mtime +1

To look for files NOT older than a day:

find . -mtime -1

"." -> this folder and its sub folders
"-mtime" -> modification date
"+/-" -> older or newer
"1" -> number of days

44 Rules for Server Administration

This blog moved to a new location, please visit us at http://ramble.m2m.at.

The recent German Linux Magazin had a nice article about rules for server administration.

basics:

1. use different machines for services which need the same performance resources
2. monitor your services
3. limit your swap processes
4. do not waste memory installing unneeded applications
5. separate partitions for system, logs and data
6. log everything
7. save the configuration before any change
8. keep static content in the cache
9. stop intruders at the firewall
10. use port knocking

web server:

1. choose the multi-processing module which fits your CPUs
2. use caching
3. limit usage of .htaccess
4. do not use symbolic links
5. do not use lookups
6. optimize MaxClients
7. do not log everything
8. use sendfile
9. use MMAP
10. switch of server-status

mail server:

1. limit the number of instances
2. use the spam filter enabled RAM disk
3. cache DNS requests
4. use postfix only once per mail
5. use reject_unkown_sender_domain
6. only use local data for postfix lookups
7. use rate limiting for clients
8. kick problematic mails

database server:

1. use the correct index type
2. delete an unneeded index
3. optimize your tables
4. optimize your SQL statements
5. use soft parsing
6. limit the size of your tables
7. separate OLTP and DSS
8. use persistent connections
9. be careful with the timing of batch jobs
10. monitor the number of connections

samba:

1. do not touch your configuration
2. provide enough RAM
3. monitor the network
4. activate Oplocks
5. use Winbind
6. deactivate "case sensitive"

Read the article it is really nice.

File Scrubber for iLiad

Copying files from Mac OS X to the iRex iLiad reader creates .DS_Store files and ._ files on the iLiad. Sometimes this seems to be a problem - some PDFs could not be opened any more. Unfortunately those files are not visible in the OS X finder. Connecting the iLiad to an WinXP computer allows to remove them but it is really clumsy having to use multiple computers.

Matt Jadud, wrote an OS X a application called iliad-scrub which runs through the iLiad folder and cleans the files automatically. Thanks Matt!

chm to pdf

CHM - Microsoft Compressed HTML Help - is a proprietary format for online help files, developed by Microsoft. Viewing CHM files using other operating systems is sometimes a little bit difficult.
Recently a CHM plug-in appeared for firefox which should be some help.
Sometimes it is still necessary to convert CHM files into other formats. While there are quite a lot of applications which could do that easily on Windows, it is still tricky for non-Windows systems.

e.g. for Mac OS X or other UNIX based OS

First you have to unpack the html files.

1. Download the chmtools package.
   
2. Unzip it: tar -zxf chmtools.tar.gz
3. Go to the chmtools folder: cd chmtools
4. Compile it: make
5. Move the new command somewhere you can easily access it (you might have to become root to be able to do that), eg: su; cp chmdump /usr/bin
   

Step 1. to 5. you have to do only once.

6. Now it is time to unpack the CHM file, eg: chmdump file.chm newFolder

Now we have to install two software packages which will do the actual html to pdf conversion.

7. Download the fltk source (should be version 1.1 or above)
   
8. Unzip it, eg: tar -yxf fltk-1.1.7-source.tar.bz2
9. Go to the fltk folder, eg: cd fltk-1.1.7
10. Compile it: make
11. It could be you need to configure the compile process for your system - have a look at their manual.
    
12. Install the new commands (you have to become root to be able to do that), eg: su; make install
13. Download the htmldoc source
    
14. Unzip it, eg: tar -yxf htmldoc-1.8.27-source.tar.bz2
15. Go to the fltk folder, eg: cd htmldoc-1.8.27
16. Compile it: make
17. It could be you need to configure the compile process for your system - have a look at their manual.
    
18. Install the new commands (you have to become root to be able to do that), eg: su; make install

Step 7. to 18. you have to do only once.

19. Now look for the html files in the folder chmdump created.
20. Go there, eg: cd newFolder
21. Now you have to create a batch file containing all the html files you want to have in your pdf. Eg: ls *.thml > test.book
22. Sometimes the files are not in the order you like. Use your favorite text editor to adjust that.
23. Add the following two lines at the top of test.book to adjust the layout the pdf. The given format is best if you want to use the pdf file on your iLiad reader.

#HTMLDOC
-t pdf --webpage --size 12x15cm --pscommands --gray --jpeg -f test.pdf

24. Run the batch file: htmldoc --batch test.book
25. The result should be a pdf file called test.pdf.

Have fun