Man Page of lsmod

NAME
       lsmod - program to show the status of modules in the Linux Kernel

SYNOPSIS
       lsmod

DESCRIPTION
       lsmod  is  a  trivial  program which nicely formats the contents of the
       /proc/modules, showing what kernel modules are currently loaded.

COPYRIGHT
       This manual page Copyright 2002, Rusty Russell, IBM Corporation.

SEE ALSO
       modprobe(8), modinfo(8)



                                  2002-12-27                          LSMOD(8)

Man Page of modprobe

MODPROBE(8)                                                        MODPROBE(8)



NAME
       modprobe - program to add and remove modules from the Linux Kernel

SYNOPSIS
       modprobe [ -v ] [ -V ] [ -C config-file ] [ -n ] [ -i ] [ -q ] [ -b ] [
       -o modulename ] [ modulename ] [ module parameters ... ]


       modprobe [ -r ] [ -v ] [ -n ] [ -i ] [ modulename ... ]


       modprobe [ -l ] [ -t dirname ] [ wildcard ]


       modprobe [ -c ]


       modprobe [ --dump-modversions ] [ filename ... ]


DESCRIPTION
       modprobe intelligently adds or removes a module from the Linux  kernel:
       note  that  for  convenience, there is no difference between _ and - in
       module  names.   modprobe  looks  in  the  module  directory  /lib/mod-
       ules/`uname  -r`  for  all  the modules and other files, except for the
       optional  /etc/modprobe.conf  configuration  file  and  /etc/modprobe.d
       directory (see modprobe.conf(5)). modprobe will also use module options
       specified on the kernel command line in the form of  ..

       Note  that  this version of modprobe does not do anything to the module
       itself: the work of resolving symbols and understanding  parameters  is
       done  inside the kernel.  So module failure is sometimes accompanied by
       a kernel message: see dmesg(8).

       modprobe expects an up-to-date modules.dep file, as generated by depmod
       (see  depmod(8)).  This file lists what other modules each module needs
       (if any), and modprobe uses this to add or  remove  these  dependencies
       automatically.  See modules.dep(5)).

       If any arguments are given after the modulename, they are passed to the
       kernel (in addition to any options listed in the configuration file).

OPTIONS
       -v --verbose
              Print messages about what the program is  doing.   Usually  mod-
              probe only prints messages if something goes wrong.

              This  option  is  passed  through  install or remove commands to
              other modprobe  commands  in  the  MODPROBE_OPTIONS  environment
              variable.

       -C --config
              This  option  overrides the default configuration directory/file
              (/etc/modprobe.d or /etc/modprobe.conf).

              This option is passed through  install  or  remove  commands  to
              other  modprobe  commands  in  the  MODPROBE_OPTIONS environment
              variable.

       -c --showconfig
              Dump out the effective configuration from the  config  directory
              and exit.

       -n --dry-run --show
              This  option  does  everything but actually insert or delete the
              modules (or run the install or remove commands).  Combined  with
              -v, it is useful for debugging problems.

       -i --ignore-install --ignore-remove
              This  option  causes  modprobe to ignore install and remove com-
              mands in the configuration file (if any) for the  module  speci-
              fied  on  the command line (any dependent modules are still sub-
              ject to commands set for them in the configuration  file).   See
              modprobe.conf(5).

       -q --quiet
              Normally  modprobe  will report an error if you try to remove or
              insert  a  module  it  can't  find  (and  isn't  an   alias   or
              install/remove  command).   With this flag, modprobe will simply
              ignore any bogus names (the kernel uses  this  to  opportunisti-
              cally probe for modules which might exist).

       -r --remove
              This  option causes modprobe to remove rather than insert a mod-
              ule.  If the modules it depends on  are  also  unused,  modprobe
              will  try  to  remove them too.  Unlike insertion, more than one
              module can be specified on the command line (it  does  not  make
              sense to specify module parameters when removing modules).

              There  is  usually  no  reason to remove modules, but some buggy
              modules require it.  Your kernel may not support removal of mod-
              ules.

       -V --version
              Show version of program and exit.

       -f --force
              Try  to  strip  any versioning information from the module which
              might otherwise stop it from loading: this is the same as  using
              both  --force-vermagic and --force-modversion.  Naturally, these
              checks are there for your protection, so using  this  option  is
              dangerous.

              This applies to any modules inserted: both the module (or alias)
              on the command line and any modules it on which it depends.

       --force-vermagic
              Every module contains a small string containing important infor-
              mation,  such  as the kernel and compiler versions.  If a module
              fails to load and the kernel complains that the "version  magic"
              doesn't match, you can use this option to remove it.  Naturally,
              this check is there for your protection, so this using option is
              dangerous.

              This applies to any modules inserted: both the module (or alias)
              on the command line and any modules on which it depends.

       --force-modversion
              When modules are compiled with CONFIG_MODVERSIONS set, a section
              detailing  the versions of every interfaced used by (or supplied
              by) the module is created.  If a module fails to  load  and  the
              kernel  complains  that  the module disagrees about a version of
              some interface, you can use "--force-modversion" to  remove  the
              version  information altogether.  Naturally, this check is there
              for your protection, so using this option is dangerous.

              This applies any modules inserted: both the module (or alias) on
              the command line and any modules on which it depends.

       -l --list
              List all modules matching the given wildcard (or "*" if no wild-
              card is given).  This option is provided for backwards  compati-
              bility: see find(1) and basename(1) for a more flexible alterna-
              tive.

       -a --all
              Insert all module names on the command line.

       -t --type
              Restrict -l to  modules  in  directories  matching  the  dirname
              given.  This option is provided for backwards compatibility: see
              find(1) and basename(1) for a more flexible alternative.

       -s --syslog
              This option causes any error messages to go through  the  syslog
              mechanism  (as  LOG_DAEMON with level LOG_NOTICE) rather than to
              standard error.  This is also automatically enabled when  stderr
              is unavailable.

              This  option  is  passed  through  install or remove commands to
              other modprobe  commands  in  the  MODPROBE_OPTIONS  environment
              variable.

       -S --set-version
              Set  the kernel version, rather than using uname(2) to decide on
              the kernel version (which dictates where to find the modules).

       --show-depends
              List the dependencies of a module (or alias), including the mod-
              ule  itself.   This  produces  a  (possibly empty) set of module
              filenames, one per line, each starting with  "insmod".   Install
              commands  which  apply are shown prefixed by "install".  It does
              not run any of the install commands.  Note that  modinfo(8)  can
              be  used  to  extract  dependencies  of a module from the module
              itself, but knows nothing of aliases or install commands.

       -o --name
              This option tries to rename the module which is  being  inserted
              into  the kernel.  Some testing modules can usefully be inserted
              multiple times, but the kernel refuses to have  two  modules  of
              the  same  name.   Normally, modules should not require multiple
              insertions, as that would make them useless  if  there  were  no
              module support.

       --first-time
              Normally,  modprobe  will  succeed  (and  do nothing) if told to
              insert a module which is already present or to remove  a  module
              which isn't present.  This is ideal for simple scripts; however,
              more complicated scripts often want  to  know  whether  modprobe
              really  did  something: this option makes modprobe fail for that
              case.

       --dump-modversions
              Print out a list of module versioning information required by  a
              module.  This  option is commonly used by distributions in order
              to package up a Linux  kernel  module  using  module  versioning
              deps.

       -b --use-blacklist
              This  option  causes modprobe to apply the blacklist commands in
              the configuration files (if any) to module names as well.  It is
              usually used by udev(7).

       -d --dirname
              Directory  where  modules  can be found, /lib/modules/RELEASE by
              default.

       --allow-unsupported-modules
              Load unsupported modules even if disabled in configuration.

RETURN VALUE
       modprobe returns 0 on success, 1 on an unspecified error and 2  if  the
       module  is not supported. Use the --allow-unsupported-modules option to
       force using an unsupported module.

ENVIRONMENT
       The MODPROBE_OPTIONS environment variable can  also  be  used  to  pass
       arguments to modprobe.

COPYRIGHT
       This manual page Copyright 2002, Rusty Russell, IBM Corporation.

SEE ALSO
       modprobe.conf(5), lsmod(8), modinfo(8)



                               15 September 2009                   MODPROBE(8)

Windows Internet Share through WIFI ad hoc

Open the Network and Sharing Center from windows control panel

Make sure the "Network discovery" is on on the active Internet connection and click "Manage wireless network" on the top left of the window.

Click "Add" button in the "Manage Wireless Network" window and then select "Create an ad hoc network" in the popped window

Press "Next" button and input the network name and at least 8 characters for password in then next pop up window, then press "Next".After waiting windows create the ad hoc press "Close" button to finish the ad hoc network creatation

Go back to "Network Connection" window either by click "Manage Network Connection" on the top left of "Network and Sharing Center" or execute ncpa.cpl in the DOS command line.

Right click the active Internet connection and go to "sharing" tab

Tick "Allow other network users to connect through this computer's Internet connection" and "Establish a dial-up connection whenever a computer on my network attempts to access the Internet".

Select the network connection which you want to share Internet through in the "Select a private network connection" drop down menu. In this case select "Wireless Network Connection". Finally press "ok" button. 

Now connect other devices to this ad hoc and use DHCP for IP and DNS address to connect to Internet  

Linux File Commond

• Display the absolutly path of the current directory
  pwd
• Display the contained files and sub directories in the current directory
  ls [option] [filenamePattern]
  Most used options include -a for displaying all files, -l for displaying all the informations for each file,
• Create one/more files
  touch file name or file name pattern
  eg: touch {report,draft}_{AUG,SEP,NOV}{1,2,3}
• Create directory
  mkdir
• Remove directory
  rmdir
• Copy files
  cp
• Move files
  mv
• Link files
  ln -s originalFile linkFile
  ln originalFile linkFile
• Display information, display all the matches of the wildcard pattern, that usefull to avoid operation on wrong files when use echo before use wildcard pattern delete or move files.
  echo [wildcard pattern]
• Change the file permissions
  chmod permission fileName
  Owner                     Group                    Others
  execute write read    execute write read   execute write read
           1      2     4             1      2     4            1      2     4
• Change the file owner
  chown username filename
• Change the file owner group
  chown username:groupName fileName
• Search files
• wildcard * ? ~
• Display file content
  
  • cat filename display the contents of the file
  • less fileName1 [fileName 2 …fileName n] view one or more files at the same time :n(to view next page) :p(to view previous page) to navigate from pages and automaticaly paginates the file.
  • head -number fileName  view the fist number of lines in the file
  • tail -number fileName  view the last number of lines in the file

Linux User Mangement Command

• Display current user information
  
  • w display who is logged on and what they are doing.
  • whoami display the current user’s username
  • groups display the current user’s group
  • id display the uid,gid and groups of the current user
• Create a user
  useradd username
• Switch between users
  su username  Note: su - change user to root user and current directory to root’s home directory. su root   change user to root user without changing current directory.

Search files in Linux

There are couples of tools used to find things in Linux.

• find [where] [search patterns][actions]
  search patterns include:
  
  • -name fileNamePattern  match is case sensitive
  • -iname fileNamePattern  match is case insensitive
  • -size [+,-]size (b,c,w,k,M,G) + means great than -means less than
  • -user  username  username is the owner of the files
  • -mmin n  searching files which be modified n mins ago
  • -amin n  searching files which be accessed n mins ago
  • -and/-or/!  are the boolean operator which connect two or more patterns
  actions include:
  
  • -delete
  • exec command
  examples:
  
  • $ find / -name ‘*.c’ 2>/dev/null
    find any .c files under the root directory and discard the error message. 2 indicates the error stream in Linux, and /dev/null is the device where anything you send simply disappears. So 2>/dev/null in this case means that while finding for the files, in case any error messages pop up simply send them to /dev/null i.e. simply discard all error messages.
  • $ find /etc -name ‘*.conf’ -exec ls -l {} \;
    find any .conf files under /etc directory and execute ls -l on the search result. {} indicate the search result \ indicate the end of the command.

Linux LVM Snapshot

LVM Snapshot use smaller logic volume to represent the whole data on the large logic volume and only save the data writing to the original LV when the snapshot LV is mounted. The snapshot LV will be automatically unmount when it is full. Thus the size of the snapshot LV must be larger than the possible data may changed during the time of the snapshot LV mount on the system.It is usfull when execute some script on the live system. For exmple back a database drive when the database still running.

To create a snapshot LV use following command:
# lvcreate -L10G -s -n snapshotName /dev/volgroupName/LVname

To mount a snapshot LV use following command:
# mkdir /mnt/locationName/snapshotLVName
# mount /dev/volgroupName/snapshotLVName /mnt/locationName/snapshotLVName

To backup a LV
tar -pczf /backups/root.tar.gz /mnt/locationName/snapshotLVName

To remove a snapshot LV use following command:
# umount /mnt/locationName/LVName
# lvremove /dev/ops/dbbackup 

Backup with tar

tar [operation] [option] target source
There are three commonly used operations `—create’, `—list’, and `—extract’ or ‘-c’, ‘-t’ and ‘-x’
And there are six commonly used options ‘-C’, ‘-f’, ‘-j’, ‘-p’, ‘-v’ and ‘-z’.

• ‘-C’, change to directory 
• ‘-f’, use archive file or device F (default “-“, meaning stdin/stdout)
• ‘-j’, filter archive through bzip2, use to decompress *.bz2 files
• ‘-p’, extract all protection information
• ‘-v’, verbosely list files processed
• ‘-z’, filter the archive through gzip

Examples:

• Verbosely create a tar archive name.tar from sourceFiles or sourceDirectory
  tar -cvf name.tar sourceFiles
  tar -cvf sourceDirectory/
• Verbosely create a tar file name.tar.gz from souceFiles and compress it use gzip
  tar -czf name.tar.gz sourceFiles
• Extract name.tar.gz from name.tar.gz
  tar -xzf name.tar.gz
• Extract one file test.txt from name.tar.gz
  tar -xzf name.tar.gz test.txt
• List archive members from name.tar
  tar -tvf name.tar

Customize Linux Bash Envirenment

Configure .bashrc to customize user’s bash environment.
.bashrc file is locate in the user’s home directory. It contain lots of configurable items which can customize how the bash looks like and how user interactive with bash.

• Aliases could be configured under ‘#User specific aliases and functions’ in the .bashrc file. After add aliases item in the .bashrc file, user need log-off and log-in the system or restart bash by execute ‘bash’ command in the terminal to active the newly added aliases.
  Aliases example: alias cls=’clear’
• Bash Prompt could be configured under ‘# Source global definitions’ in the .bashrc file. Environment variable $PS1 which could be change by PS1=’optionsPlusAnything’ is represent the bash prompt. The available options are as following
  
  • \a an ASCII bell character (07)
  • \d the date in “Weekday Month Date” format
  • (e.g., “Tue May 26”)
  • \e an ASCII escape character (033)
  • \h the hostname up to the first `.’
  • \H the hostname
  • \n newline
  • \r carriage return
  • \s the name of the shell, the basename of $0
  • (the portion following the final slash)
  • \t the current time in 24-hour HH:MM:SS format
  • \T the current time in 12-hour HH:MM:SS format
  • \@ the current time in 12-hour am/pm format
  • \u the username of the current user
  • \v the version of bash (e.g., 2.00)
  • \V the release of bash, version + patchlevel
  • (e.g., 2.00.0)
  • \w the current working directory
  • \W the basename of the current working direc-
  • tory
  • \! the history number of this command
  • \# the command number of this command
  • \$ if the effective UID is 0, a #, otherwise a
  • $
  • \nnn the character corresponding to the octal
  • number nnn
  • \ a backslash
  • \[ begin a sequence of non-printing characters,
  • which could be used to embed a terminal con-
  • trol sequence into the prompt
  • \] end a sequence of non-printing characters
• Configure bash shell options with set/shopt
  set -o check the current bash shell option setting
  set -o bashOption to enable the bashOption
  set +o bashOptioon to disable the bashOption

F-port Anti Virus for Linux

• Download F-port for Linux workstation from http://www.f-prot.com/products/home_use/linux/ 
• Extract the downloaded file to the user’s home folder use tar -xvf filename 
• Enter the extracted folder execute ./install-f-prot.pl then type yes if system ask ln -fs /home/username/f-port/fpscan /usr/sbin/fpscan 
• Preform a scan by execute fpscan /filepath/to/scan

Restore Ubuntu gnome panel

In the terminal execute following command to restore gnome panel to default setting.
$ gconftool-2 --shutdown
$ rm -rf .gconf/apps/panel
$ pkill gnome-panel

Linux Permission and Owernship

File Permission
chmod permissionNumber fileName

Owner			Group			Other Users
Execute	Write	Read	Execute	Write	Read	Execute	Write	Read
1	2	4	1	2	4	1	2	4

File Ownership
chown userName fileName
chown userName.groupName fileName

Uninstall VMWare Player3.0 on Fedora 12

[root@MyPC resources]# vmware-uninstall
You have gotten this message because you are either downgrading VMware
Workstation, Player, or VIX, or because you attempted to run either
vmware-uninstall or vmware-uninstall-vix.

If you are downgrading, please uninstall all newer versions first, then
install again.

The vmware-uninstall* scripts have been deprecated. Instead, please use
the vmware-installer.

Long form:
vmware-installer --uninstall-product PRODUCT
Short form:
vmware-installer -u PRODUCT

Where PRODUCT is one of vmware-workstation, vmware-player, or vmware-vix.

For a list of which products are installed, you may run:
vmware-installer --list-products
or:
vmware-installer -l


[root@MyPC resources]# vmware-installer -l
Product Name Product Version
====================== ====================
vmware-player 3.0.1.227600
[root@MyPC resources]# vmware-installer --uninstall-product vmware-player

Linux LVM Snapshot

LVM Snapshot use smaller logic volume to represent the whole data on the large logic volume and only save the data writing to the original LV when the snapshot LV is mounted. The snapshot LV will be automatically unmount when it is full. Thus the size of the snapshot LV must be larger than the possible data may changed during the time of the snapshot LV mount on the system.It is usfull when execute some script on the live system. For exmple back a database drive when the database still running.

To create a snapshot LV use following command:
# lvcreate -L10G -s -n snapshotName /dev/volgroupName/LVname

To mount a snapshot LV use following command:
# mkdir /mnt/locationName/snapshotLVName
# mount /dev/volgroupName/snapshotLVName /mnt/locationName/snapshotLVName

To backup a LV
tar -pczf /backups/root.tar.gz /mnt/locationName/snapshotLVName

To remove a snapshot LV use following command:
# umount /mnt/locationName/LVName
# lvremove /dev/ops/dbbackup 

Install Mac4Lin on Ubuntu 10.1

• Download Mac4Lin from http://sourceforge.net/projects/mac4lin/
• unzip it to a temp folder
• Make sure you have ~/.themes and ~/.icons if you not install Mac4Lin on Ubuntu 10.1
• Install Emerald Theme Manager
• Install Tracker
• execute Mac4Lin_Install_v1.0.sh
• Type 'y' and enter when system popup "Do you want to enable Metacity Compositor?"
• Type 'y' and enter when system popup "The following componenets require root access. You can opt out of installing them as they can be manually installed as well. Would you like to install these components?"
• Install Avant Window Navigator

Fix Kmplayer "class not registered" problem

I have successfully installed kmplayer on Windows 7 Ultimate, however it will pop up an error message "class not registered" After check window troubleshooting message, found the problem was that I have downloaded and installed Adobe flash player from firefox not IE. That case the adobe flash player not active the activeX.

Uninstall Adobe flash player and reinstall it from IE problem fixed.

ISCSI Enterprise Target on RHEL

NAME

/etc/ietd.conf - configuration for iSCSI Enterprise Target Daemon

SYNOPSIS

/etc/ietd.conf

DESCRIPTION

/etc/ietd.conf contains configuration information for the ietd (8) command. This is the place, where you configure your iSCSI targets and daemon defaults. Only lines starting with ‘#’ are ignored. Putting ’#’ in the middle of a line is disallowed. A line may be extended across multiple lines by making the last character a backslash. The "Yes" and "No" for parameter values are case sensitive. The parameter names are case insensitive. The file consists of a global part and zero or more "Target" stanzas. Everything until the first target definition belongs to the global configuration. Here is an example: IncomingUser joe secret OutgoingUser jack secret2 Target iqn.2001-04.com.example:storage.disk2.sys1.xyz IncomingUser jim othersecret OutgoingUser james yetanothersecret Lun 0 Path=/dev/sdc,Type=fileio Lun 1 Sectors=10000,Type=nullio Alias Test HeaderDigest None DataDigest None MaxConnections 1 InitialR2T Yes ImmediateData No MaxRecvDataSegmentLength 8192 MaxXmitDataSegmentLength 8192 MaxBurstLength 262144 FirstBurstLength 65536 DefaultTime2Wait 2 DefaultTime2Retain 20 MaxOutstandingR2T 8 DataPDUInOrder Yes DataSequenceInOrder Yes ErrorRecoveryLevel 0 Stanzas start with the word "Target" and the target name. This name must be a globally unique name, as defined by the iSCSI standard : the "iSCSI Qualified Name". The daemon brings the targets up in the order listed.

GLOBAL OPTIONS

Global Options are case sensitive. [IncomingUser ] The and used during discovery sessions to authenticate iSCSI initiators. Several of those can be specified for discovery. If no IncomingUser is specified, any initiator is allowed to open a discovery session. HINT: RFC 3720 requires to be 12 characters long. This is enforced e.g. by MS Initiator. [OutgoingUser ] The and used during discovery sessions to authenticate the target to initiators. Only one outgoing / combination may be specified. HINT: RFC 3720 requires to be 12 characters long. This is enforced e.g. by MS Initiator. Target iqn..[:] A target definition and the target name. The targets name (the iSCSI Qualified Name ) must be a globally unique name (as defined by the iSCSI standard) and has to start with iqn followed by a single dot. The EUI-64 form is not supported. is the date (year and month) at which the domain is valid. This has to be followed by a single dot and the reversed domain name. The optional - which is freely selectable - has to be separated by a single colon. For further details please check the iSCSI spec. Here is an example: Target iqn.2004-07.com.example.host:storage.disk2.sys1.xyz

TARGET OPTIONS

Target options are also case sensitive. [IncomingUser ] The and used to authenticate the iSCSI initiators to this target. It may be different from the username and password in section GLOBAL OPTIONS, which is used for discovery. If you omit the IncomingUser Option, connections are allowed without authentication. A has to be provided, if there is a given. Specifying several different IncomingUser accounts is supported. [OutgoingUser ] The and used to authenticate this iSCSI target to initiators. Only one OutgoingUser per target is supported. It may be different from the username and password in section GLOBAL OPTIONS, which is used for discovery. A has to be provided, if there is a given. Lun Path=,Type=(fileio|blockio)[,ScsiId=][,ScsiSN=][,IOMode=(wb|ro)] | Sectors=,Type=nullio Parameters after should not contain any blank space character except the first blank space after is needed. This line must occur at least once. The value of can be between 0 and 2^14-1. In fileio mode (default), it defines a mapping between a "Logical Unit Number" and a given device , which can be any block device (including regular block devices like hdX and sdX and virtual block devices like LVM and Software RAID devices) or regular files. In blockio mode, it defines a mapping between a "Logical Unit Number" and a given block device . This mode will perform direct block i/o with the device, bypassing page-cache for all operations. This allows for efficient handling of non- aligned sector transfers (virtualized environments) and large block transfers (media servers). This mode works ideally with high-end storage HBAs and for applications that either do not need caching between application and disk or need the large block throughput. Optionally a can be specified to assign a unique ID to the iSCSI volume. This is useful e.g. in conjunction with a multipath-aware initiator host accessing the same through several targets. The must not exceed 16 characters and controls the content of VPD 0x83. The must not exceed 16 characters and controls the content VPD 0x80. By default, LUNs are writable, employing write-through caching. By setting IOMode to "ro" a LUN can only be accessed read only. Setting IOMode to "wb" will enable write-back caching. Please note that this could lead to data loss e.g. in case of power outages, so it is strongly recommended to use an UPS when enabling write-back caching. NOTE: IOMode "wb" is ignored when employing blockio. In nullio mode, it defines a mapping between a "Logical Unit Number" and an unnamed virtual device with sectors. This is ONLY useful for performance measurement purposes. All writes to this virtual device will be discarded and reads will return random data. [Alias ] This assigns an optional to the target. [HeaderDigest ] Optional. If set to "CRC32C" and the initiator is configured accordingly, the integrity of an iSCSI PDU’s header segments will be protected by a CRC32C checksum. The default is "None". Note that header digests are not supported during discovery sessions. [DataDigest ] Optional. If set to "CRC32C" and the initiator is configured accordingly, the integrity of an iSCSI PDU’s data segment will be protected by a CRC32C checksum. The default is "None". Note that data digests are not supported during discovery sessions. [MaxConnections ] Optional. Has to be set to "1" (in words: one), which is also the default. [InitialR2T ] Optional. If set to "Yes" (default), the initiator has to wait for the target to solicit SCSI data before sending it. Setting it to "No" allows the initiator to send a burst of FirstBurstLength bytes unsolicited right after and/or (depending on the setting of ImmediateData ) together with the command. Thus setting it to "No" may improve performance. [ImmediateData ] Optional. This allows the initiator to append unsolicited data to a command. To achieve better performance, this should be set to "Yes". The default is "No". [MaxRecvDataSegmentLength ] Optional. Sets the maximum data segment length that can be received. The should be set to multiples of PAGE_SIZE. Currently the maximum supported value is 64 * PAGE_SIZE, e.g. 262144 if PAGE_SIZE is 4kB. Configuring too large values may lead to problems allocating sufficient memory, which in turn may lead to SCSI commands timing out at the initiator host. The default value is 8192. [MaxXmitDataSegmentLength ] Optional. Sets the maximum data segment length that can be sent. The actually used is the minimum of MaxXmitDataSegmentLength and the MaxRecvDataSegmentLength announced by the initiator. The should be set to multiples of PAGE_SIZE. Currently the maximum supported value is 64 * PAGE_SIZE, e.g. 262144 if PAGE_SIZE is 4kB. Configuring too large values may lead to problems allocating sufficient memory, which in turn may lead to SCSI commands timing out at the initiator host. The default value is 8192. [MaxBurstLength ] Optional. Sets the maximum amount of either unsolicited or solicited data the initiator may send in a single burst. Any amount of data exceeding this value must be explicitly solicited by the target. The should be set to multiples of PAGE_SIZE. Configuring too large values may lead to problems allocating sufficient memory, which in turn may lead to SCSI commands timing out at the initiator host. The default value is 262144. [FirstBurstLength ] Optional. Sets the amount of unsolicited data the initiator may transmit in the first burst of a transfer either with and/or right after the command, depending on the settings of InitialR2T and ImmediateData should be set to multiples of PAGE_SIZE. Configuring too large values may lead to problems allocating sufficient memory, which in turn may lead to SCSI commands timing out at the initiator host. The default value is 65536. [DefaultTime2Wait ] Currently not supported. [DefaultTime2Retain ] Currently not supported. [MaxOutstandingR2T ] Optional. Controls the maximum number of data transfers the target may request at once, each of up to MaxBurstLength bytes. The default is 1. [DataPDUInOrder ] Optional. Has to be set to "Yes" - which is also the default. [DataSequenceInOrder ] Optional. Has to be set to "Yes" - which is also the default. [ErrorRecoveryLevel ] Optional. Has to be set to "0" (in words: zero), which is also the default. [Wthreads ] Optional. The iSCSI target employs several threads to perform the actual block I/O to the device. Depending on your hardware and your (expected) workload, the number of these threads may be carefully adjusted. The default value of 8 should be sufficient for most purposes. [QueuedCommands ] Optional. This parameter defines a window of commands an initiator may send and that will be buffered by the target. Depending on your hardware and your (expected) workload, the value may be carefully adjusted. The default value of 32 should be sufficient for most purposes.

Show IET ISCSI target information
# cat /proc/net/iet/volume

Show IET ISCSI connected session information
# cat /proc/net/iet/session

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mount ntfs partition in RHEL 5.4

New version RHEL is not officially support NTFS partition. The third party plug in ntfs-3g is needed for mounting NTFS partition in the RHEL. There are a detailed instruction on CentOS wiki http://wiki.centos.org/TipsAndTricks/NTFS?highlight=(ntfs)

Add rpmforge to repository

yum install fuse fuse-ntfs-3g

Add Windows XP to the GRUB menu

1. Back up GRUB configuration file.
   cp /boot/grub/menu.lst /root/backup/menu.lst.grub.bak
   cp /boot/grub/menu.lst /boot/grub/menu.lst.bak
2. Add Windows XP boot up option in the GRUB menu.
   Vi /boot/grub/menu.lst
   add following lines in the menu.lst:
   title Windows XP
   map (hd0) (hd1)
   map (hd1) (hd0)
   root (hd1,0)
   chainloader +1
   
   
   
   
   Note:
   map (hd0) (hd1)
   map (hd1) (hd0)
   This two lines are called "virtual swap" which can solve windows installed on second harddisk.
   root (hd1,0) (hd1,0)means on second harddisk's first partition.
   
   
   

Enable Dlink DWA-110 USB Wireless Adapter on CentOs 5.4

Plug in the USB wireless adapter

Check the chipset of the USB wireless adapter by using following command.

[root@localhost sbin]# lsusb
Bus 005 Device 001: ID 0000:0000
Bus 001 Device 004: ID 07d1:3c07 D-Link System Wireless G DWA-110 Adapter

[root@localhost sbin]# lsmod | grep rt
rt73usb 60481 0
crc_itu_t 35265 1 rt73usb
rt2x00usb 47041 1 rt73usb
rt2x00lib 56641 2 rt73usb,rt2x00usb
mac80211 182985 2 rt2x00usb,rt2x00lib
cfg80211 63825 2 rt2x00lib,mac80211

Enable ELRepo repository

To install ELRepo for RHEL5, CentOS-5 or SL5:

rpm -Uvh http://elrepo.org/elrepo-release-0.1-1.el5.elrepo.noarch.rpm

Import the public key:

rpm --import http://elrepo.org/RPM-GPG-KEY-elrepo.org

Install firmware for Dlink DWA-110 wireless adapter:
yum --enablerepo=elrepo install rt73usb-firmware

Open NetworkManager serveice at the system start up:
chkconfig NetworkManager on

service NetworkManager start

Turn off network and wpa_supplicant services at boot time as NetworkManager will in charge the network connections.
chkconfig network off
chkconfig wpa_supplicant off


Reference:

Making Wireless work on your laptop(or desktop) http://wiki.centos.org/HowTos/Laptops/Wireless#head-a7388039af96da5400e599133447452d2ca61fb5