Firefox settings to change

In Firefox 2, type "about:config" in the location bar, and press enter. You'll get some settings. Here are the ones I change:

Old New Setting/Affect
3 1 browser.cache.check_doc_frequency - check page every load.
true false browser.cache.disk.enable - don't cache to disk
140 140 browser.tabs.tabClipWidth - don't shot close button on tabs narrower than this
100 30 browser.tabs.tabMinWidth - let tabs become this narrow
1 3 browser.startup.page - restore your previous browsing session



Here are some MS SQL Tips, Tricks, Recipes, etc.:

  • Find out who's using what databases:
    1. Open SQL Query Analyzer
    2. type "exec sp_who" into the Query window.
    3. Click "Execute Query" or press F5.
  • From cryptosid at experts-exchange:
    • before using DBCC REBUILD_LOG better check this article and read it through

      a safe alternative would be
      Backup the consistent Database.
      and RESTORE the database with the MOVE option using which u can move the database files to whichever drive u want...
  • Get information on a DB's logfile:
    1. Open Query Analyzer
    2. Type this in the query window, then click Execute Query:
      • use db_name
      • dbcc LOGINFO
  • Detach and re-attach a database:
    1. confirm that nothing has the db open. Open QA and run "exec sp_who"
    2. If nobody is using the db, detach the database with the QA command "EXEC sp_detach_db 'db_name' ", or right-click the DB in the enterprise mgr and select "detach database".
    3. Re-attach the DB by using the QA command "EXEC sp_attach_db 'db_name', 'x:\full\path\to\db\file\db_filename.MDF' " or by right-clicking the databases in the enterprise mgr, and select "attach database".
  • How to set up SQL mail
    • http://support.microsoft.com/?id=263556
  • Safely delete a transaction log:
    1. make sure nobody's using the database, as above under "Detach..."
    2. Backup the database.
    3. make sure nobody's using the database still.
    4. detach the database, as above.
    5. rename the log file (.LDF file)
    6. re-attach the database, as above.
    7. logfile should be automatically re-created.
  • From rsrm at experts-exchange, http://www.experts-exchange.com/Databases/Microsoft_SQL_Server/Q_20823435.html
    • Comment from rsrsm
      Date: 12/11/2003 07:29PM PST

      If the log file is deleted for the database and SQL server is not able to locate it..you can rebuild the log. try the following steps (But if the log file is not deleted then you can ignore this comment):

      REBUILD LOG and recover a suspect database:

      1. Back up the .mdf/.ndf and .ldf files.

      2. Change the database context to Master and allow updates to system tables:

      Use Master
      sp_configure 'allow updates', 1
      reconfigure with override

      3. Set the database in Emergency (bypass recovery) mode:

      select * from sysdatabases where name = ''
      -- note the value of the status column for later use
      begin tran
      update sysdatabases set status = 32768 where name = ''
      -- Verify one row is updated before committing
      commit tran

      If you run DBCC REBUILD_LOG without setting the database in Emergency
      the command does not work. You do not receive an error, but the log is
      rebuilt either.

      4. Stop and restart SQL server.

      If you run DBCC REBUILD_LOG without recycling the server, the following
      message displays:

      Server: Msg 5023, Level 16, State 2, Line 1 Database must be put in
      recovery mode to rebuild the log. DBCC execution completed. If DBCC
      error messages, contact your system administrator.

      5. The syntax for DBCC REBUILD_LOG is as follows:

      DBCC REBUILD_LOG('','')

      where is the name of the database and is
      the physical path to the new log file, not a logical file name. If you
      do not
      specify the full path, the new log is created in the Windows NT system
      directory (by default, this is the Winnt\System32 directory).

      If the file is placed in the Winnt\System32 folder, you can move it to a
      different folder by running the following commands from the SQL Query

      sp_detach_db ''

      Move the log file over from the Winnt\System32 folder to the preferred

      sp_attach_db '', '', ''

      If a log file with the same name as specified in DBCC REBUILD_LOG already
      exists in that directory, then the following message occurs:

      Server: Msg 5025, Level 16, State 1, Line 1
      The file 'C:\MSSQL7\Data\' already exists. It should be
      renamed or deleted so that a new log file can be created.
      DBCC execution completed. If DBCC printed error messages, contact your

      You will need to specify a different filename or rename or delete the

      Rebuild the log with this code:

      DBCC TRACEON (3604)
      DBCC REBUILD_LOG('','')

      If the command is successful, the following message appears:

      Warning: The log for database '' has been rebuilt.
      Transactional consistency has been lost. DBCC CHECKDB should be run to
      validate physical consistency. Database options will have to be reset,
      extra log files may need to be deleted.

      After the log is successfully rebuilt, the database is placed in DBO Use
      mode. That is, the status of the database is 2048 irrespective of what
      status was previously. You must reset the status using sp_dboption or
      the SEM.

      6. Set the database in single-user mode and run DBCC CHECKDB to validate
      physical consistency:

      sp_dboption '', 'single user', 'true'
      DBCC CHECKDB('')
      begin tran
      update sysdatabases set status = where name = ''
      -- verify one row is updated before committing
      commit tran

      7. Turn off the updates to system tables by using:

      sp_configure 'allow updates', 0
      reconfigure with override

      WARNING: After verifying the consistency of the database by running DBCC
      and fixing any errors, please make sure to check the database for logical
      consistency as well. Because a new log has been built, the transactions in
      old log are lost, hence you must also verify the logical consistency of the
      as well.


bash shortcuts

from http://www.howtogeek.com/howto/ubuntu/keyboard-shortcuts-for-bash-command-shell-for-ubuntu-debian-suse-redhat-linux-etc/

Ctrl + A : Go to the beginning of the line you are currently typing on
Ctrl + E : Go to the end of the line you are currently typing on
Ctrl + L : Clears the Screen, similar to the clear command
Ctrl + U : Clears the line before the cursor position. If you are at the end of the line, clears the entire line.
Ctrl + H : Same as backspace
Ctrl + R : Let’s you search through previously used commands
Ctrl + C : Kill whatever you are running
Ctrl + D : Exit the current shell
Ctrl + Z : Puts whatever you are running into a suspended background process. fg restores it.
Ctrl + W : Delete the word before the cursor
Ctrl + K : Clear the line after the cursor
Ctrl + T : Swap the last two characters before the cursor
Esc + T : Swap the last two words before the cursor
Alt + F : Move cursor forward one word on the current line
Alt + B : Move cursor backward one word on the current line
Tab : Auto-complete files and folder names


SCSI Tape status codes in Linux

Status Bit   Description
BOT The tape is positioned at the beginning of the first
EOT A tape operation has reached the physical End Of
EOF The tape is positioned just after a filemark.
WR_PROT The tape (or drive) is write-protected. For some
drives this can also mean that the drive does not
support writing on the current medium type.
ONLINE The drive has a tape in place and ready for
DR_OPEN Door is open. Depending on the type of drive, this
usually means that the drive does not have a tape in
IM_REP_EN Immediate report mode. This bit is set if there are
no guarantees that the data has been physically
written to the tape when the write call returns. It
is set to zero only when the driver does not buffer
data and the drive is set not to buffer data.
SM The tape is currently positioned at a setmark. DDS
EOD The tape is positioned at the end of recorded data.
DDS specific.
D_800 This "generic" status information reports the current
density setting for 9-track 1/2 inch tape drives only.


Linux kernel debugging first steps on i386

(from the SGI XFS mailing list)

If you have compiled in kdb and you get an oops (at least in 2.4 series kernels):

Next time it hangs, enter these kdb commands and
capture the output on the serial console.

set LINES 10000
-md1c320 system_utsname
-id %eip-0x40
-dmesg 200


Hide OS and Apache version number

By default (at least on RHEL 4, CentOS 4.x, and related distros), Apache web server will give the version number of Apache, as well as your OS. This will make it easier for an attacker to guess what vulnerabilities your web server (or host OS) may have. This information can be hidden by changing these two lines in /etc/httpd/conf/httpd.conf:
ServerTokens ProductOnly
ServerSignature Off
Note that this won't actually fix any vulnerabilities, but it will make an attacker have to either guess or scan to determine what vulnerabilities you may have.

An even better idea is to front your apache with modsecurity (perhaps even on a separate (virtual) server), and have modsecurity tell everyone that your apache web server is really an IIS server.

To hide the Apache PHP version number, add/change this line in /etc/php.ini:
expose_php = Off