Rescan dynamically the scsi bus (applicable to CX Clariion SAN infrastructure)

Rescan dynamically the scsi bus

I've been working for a while with a Dell - Clariion CX-300, and the best way to add new attached LUNs was always to reboot the server.
However, that procedure is not always the most acceptable if you're in a hurry or if just want to do some tests.
I found the procedure described above, in an outdated website, but worked very well in my case.

I also recommend to use rescan-scsi-bus.sh script with the options -lwc. Type rescan-scsi-bus.sh --help to see the description of each option.

The original link is: http://www.it-sudparis.eu/s2ia/user/procacci/Doc/AX100/AX100-en008.html


After initialization ends, the server doesn't see the new devices :-( I tried a script from http://www.linux1394.org/scripts/rescan-scsi-bus.sh that should dynamically rescan the bus, but with no sucess.

$ /root/rescan-scsi-bus.sh
Host adapter 1 (qla2xxx) found.
Host adapter 2 (qla2xxx) found.
Scanning for device 1 0 0 0 ...
OLD: Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: LUNZ Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
Scanning for device 2 0 0 0 ...
OLD: Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: LUNZ Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
0 new device(s) found.
0 device(s) removed.



So I stoped powerpath and unload qla modules in order to restart the whole thing.
$ /etc/init.d/PowerPath stop
Stopping PowerPath: done
$ lsmod | grep qla
qla6312 119233 0
qla2xxx 165733 1 qla6312
scsi_transport_fc 12225 1 qla2xxx
scsi_mod 116941 5 sg,qla2xxx,scsi_transport_fc,megaraid_mbox,sd_mod
[root@pasargades /opt/Navisphere/bin]
$ modprobe -r qla6312 qla2xxx
[root@pasargades /opt/Navisphere/bin]
$ lsmod | grep qla



then reload the whole thing:

$ modprobe qla2xxx qla6312
[root@pasargades /opt/Navisphere/bin]
$ /etc/init.d/PowerPath start
Starting PowerPath: done



then it works, the kernel does see the new devices

$ cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 06 Lun: 00
Vendor: PE/PV Model: 1x2 SCSI BP Rev: 1.0
Type: Processor ANSI SCSI revision: 02
Host: scsi0 Channel: 01 Id: 00 Lun: 00
Vendor: MegaRAID Model: LD 0 RAID1 69G Rev: 521S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi3 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi3 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi4 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi4 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
[root@pasargades /opt/Navisphere/bin]
$ fdisk -l

Disk /dev/sda: 73.2 GB, 73274490880 bytes
255 heads, 63 sectors/track, 8908 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 4 32098+ de Dell Utility
/dev/sda2 * 5 583 4650817+ 83 Linux
/dev/sda3 584 1220 5116702+ 83 Linux
/dev/sda4 1221 8908 61753860 5 Extended
/dev/sda5 1221 3770 20482843+ 83 Linux
/dev/sda6 3771 5682 15358108+ 83 Linux
/dev/sda7 5683 6192 4096543+ 82 Linux swap

Disk /dev/sdb: 676.4 GB, 676457349120 bytes
255 heads, 63 sectors/track, 82241 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/sdc: 1395.8 GB, 1395864371200 bytes
255 heads, 63 sectors/track, 169704 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table

Disk /dev/sdd: 676.4 GB, 676457349120 bytes
255 heads, 63 sectors/track, 82241 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdd doesn't contain a valid partition table

Disk /dev/sde: 1395.8 GB, 1395864371200 bytes
255 heads, 63 sectors/track, 169704 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sde doesn't contain a valid partition table

Disk /dev/emcpowera: 676.4 GB, 676457349120 bytes
255 heads, 63 sectors/track, 82241 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/emcpowera doesn't contain a valid partition table

Disk /dev/emcpowerb: 1395.8 GB, 1395864371200 bytes
255 heads, 63 sectors/track, 169704 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/emcpowerb doesn't contain a valid partition table




REmarque: We can see that fdisk sees double path 'raw' devices ( /dev/sdb and /dev/sdd ) to a same device, which finnaly is presented by powerpath as /dev/emcpowera . All disk system command (fdisk etc ...) should now use that device in order to benefit the use of powerpath (load balancing and failover on our double attached FC ).//

The 'rescan' script shows that now:

$ /root/rescan-scsi-bus.sh
Host adapter 3 (qla2xxx) found.
Host adapter 4 (qla2xxx) found.
Scanning for device 3 0 0 0 ...
OLD: Host: scsi3 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
Scanning for device 4 0 0 0 ...
OLD: Host: scsi4 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0208
Type: Direct-Access ANSI SCSI revision: 04
0 new device(s) found.
0 device(s) removed.

How to run an application a daemon? Example with nsca Nagios utility

Recently I needed to make a server application run as an Unix daemon and be able to start, stop and restart it on demand. The application I’m talking about didn’t have any startup/shutdown utilities (nsca utility to send passive check results to Nagios). It runs as a script, without even detaching from the console ( unless you use the & at the end of the command line, let's say #nsca -c nsca.cfg & ).
I also did it some time ago, to make another utility work as a daemon, but today I want to share the info.
I’ll have to write a utility application that would start the process, store it’s PID in some file and somehow “daemonize” the forked process.

Let’s assume that the application we want to run is /usr/local/nagios/nsca

First, we need to create a script in /etc/init.d/ Let us name the file /etc/init.d/nsca

The file contents would look something like this:

#!/bin/bash
#
# /etc/rc.d/init.d/nsca
#
# Control to start/stop nsca utility as a daemon
# chkconfig: 345 99 01
# description: NSCA passive alerts writer for Nagios
#
# Author: Edwin Salvador (edwin.salvador@gmail.com)
#
# Changelog:
# 2009-03-23
# - First version of the script
#
# processname: nsca
# Source function library.
. /etc/init.d/functions

test -x /usr/local/nagios/nsca || exit 0

RETVAL=0

prog="NSCA passive alerts writer for Nagios"

start() {
echo -n $"Starting $prog: "
daemon /usr/local/nagios/nsca -c /usr/local/nagios/nsca.cfg
RETVAL=$?
[ $RETVAL -eq 0 ] && touch /var/lock/subsys/nsca
echo
}

stop() {
echo -n $"Stopping $prog: "
killproc /usr/local/nagios/nsca
RETVAL=$?
[ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/nsca
echo
}

#
# See how we were called.
#
case "$1" in
start)
start
;;
stop)
stop
;;
reload|restart)
stop
start
RETVAL=$?
;;
condrestart)
if [ -f /var/lock/subsys/nsca ]; then
stop
start
fi
;;
status)
status /usr/local/nagios/nsca
RETVAL=$?
;;
*)
echo $"Usage: $0 {condrestart|start|stop|restart|reload|status}"
exit 1
esac

exit $RETVAL


This is a pretty standard service start/stop/restart file. This small script will take care of controlling the PID and work as any other standard service, you don't need to remove any PID file manually, nor event to kill the process.

It can also be easyly modified to match any other program / application / script under Linux you want to daemonize !!.

Remember to assign user and group "root", and chmod 755
Use a different and unique name to each new startup script you create.

You're all set. Just use it as any usual service you run:

START:
#service start nsca
STOP:
#service stop nsca
RESTART:
#service restart nsca

If you need it to startup automatically on system boot-up:

#chkconfig nsca on

Enjoy it !

Sudo: allow a normal user to run commands as root under Linux / UNIX operating systems

I would like to run few commands such as stop or start web server as a root user. How do I allow a normal user to run these commands as root?

You need to use sudo command which is use to execute a command as another user. It allows a permitted user to execute a command as the superuser or another user, as specified in the /etc/sudoers (config that defines or list of who can run what) file. i.e. the sudo command allows users to do tasks on a Linux system as another user.

sudo is more more secure then su command. By default it logs sudo usage, command and arguments in /var/log/secure (Red Hat/Fedora / CentOS Linux) or /var/log/auth.log (Ubuntu / Debian Linux).

If the invoking user is root or if the target user is the same as the invoking user, no password is required. Otherwise, sudo requires that users authenticate themselves with a password by default (NOTE: in the default configuration this is the user's password, not the root password). Once a user has been authenticated, a timestamp is updated and the user may then use sudo without a password for a short period of time (15 minutes unless overridden in sudoers).

/etc/sudoers Syntax
Following is general syntax used by /etc/sudoers file:
USER HOSTNAME=COMMAND
Where,

USER: Name of normal user
HOSTNAME: Where command is allowed to run. It is the hostname of the system where this rule applies. sudo is designed so you can use one sudoers file on all of your systems. This space allows you to set per-host rules.
COMMAND: A simple filename allows the user to run the command with any arguments he/she wishes. However, you may also specify command line arguments (including wildcards). Alternately, you can specify "" to indicate that the command may only be run without command line arguments.
How do I use sudo?
For example, you want to give user rokcy access to halt/shutdown command and restart apache web server.
1) Login as root user

2) Use visudo command edit to edit the config file:
# visudo
3) Append the following lines to file:
rokcy localhost=/sbin/halt
rokcy dbserver=/etc/init.d/apache-perl restart
4) Save the file and exit to shell prompt.
5) Now rokcy user can restart apache server by typing the following command:
$ sudo /etc/init.d/apache-perl restart
Output:

Password:
Restarting apache-perl 1.3 web server....The sudo command has logged the attempt to the log file /var/log/secure or /var/log/auth.log file:
# tail -f /var/log/auth.log

Output:

May 13 08:37:43 debian sudo: rokcy : TTY=pts/4 ; PWD=/home/rokcy ; USER=root

If rokcy want to shutdown computer he needs to type command:
$ sudo /sbin/halt
Output:

Password:Before running a command with sudo, users usually supply their password. Once authenticated, and if the /etc/sudoers configuration file permits the user access, then the command is run. sudo logs each command run and in some cases has completely supplanted the superuser login for administrative tasks.

More examples
a) Specify multiple commands for user jadmin:
jadmin ALL=/sbin/halt, /bin/kill, /etc/init.d/httpd
b) Allow user jadmin to run /sbin/halt without any password i.e. as root without authenticating himself:
jadmin ALL= NOPASSWD: /sbin/halt
c) Allow user charvi to run any command from /usr/bin directory on the system devl02:
charvi devl02 = /usr/bin/*


Source:
http://www.cyberciti.biz/tips/allow-a-normal-user-to-run-commands-as-root.html

HowTo SSH/SCP without a password

HowTo SSH/SCP without a password.


This small HowTo will explain how to setup key-based authentication for password-less SSH and SCP usage.

This HowTo does assume the reader has some basic knowledge of ssh and a terminal, and is using an operating system that implements SSH. If you're using a Windows OS and want to use SSH, try PuTTY. For Putty, see key-based auth with Putty.

In the examples that follow please substitute 'servername' , 'ipaddress' and 'username' with the proper information for your setup. I have included a list of weblinks for the words in italic at the end of this document.

Step 1. Verify that you can connect normally (using a password) to the server you intend to setup keys for:

#### Examples ####

user@homebox ~ $ ssh username@'servername'

# Or:

user@homebox ~ $ ssh username@'ipaddress'

# If your username is the same on both the client ('homebox') and the server ('servername'):

user@homebox ~ $ ssh 'servername'

# Or:

user@homebox ~ $ ssh 'ipaddress'

# If this is your first time connecting to 'servername' (or 'ipaddress'), upon establishing a connection with the
# server you'll be asked if you want to add the servers fingerprint to the known_hosts file on your computer.
# Press 'enter' to add the fingerprint.

Step 2. Now that you're connected to the server and verified that you have everything you need for access (hopefully), disconnect by typing 'exit' .

#### Examples ####

user@servername ~ $ exit

# You should be back at:

user@homebox ~ $

Step 3. The next step is to copy a unique key generated on your 'homebox' to the server you are connecting too. First, before you generate a new key, check to see if you already have a key:

#### Example ####

user@homebox ~ $ ls -l ~/.ssh
total 20
-rwx--xr-x 1 user user 601 Feb 2 01:58 authorized_keys
-rwx--xr-x 1 user user 668 Jan 1 19:26 id_dsa
-rwx--xr-x 1 user user 599 Jan 1 19:26 id_dsa.pub
-rwx--xr-x 1 user user 6257 Feb 2 21:04 known_hosts

# The file we need to copy to the server is named id_dsa.pub. As you can see above, the file needed exists. You may or may not have other files in ~/.ssh as I do. If the key doesn't exist, however, you can make one as follows:

#### Example ####

user@homebox ~ $ ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_dsa): # Press 'enter' here
Enter passphrase (empty for no passphrase): # Press 'enter' here
Enter same passphrase again: # Press 'enter' here
Your identification has been saved in /home/user/.ssh/id_dsa.
Your public key has been saved in /home/user/.ssh/id_dsa.pub.
The key fingerprint is:
6f:c3:cb:50:e6:e9:90:f0:0f:68:d2:10:56:eb:1d:91 user@host

# Entering a password when asked during the key generation processes when prompted would require you to enter a password each time you SSH/SCP to the server which defeats the purpose of this document.

Step 4. Regardless whether you had a key ready to go or if you had to generate a new key, the next step is the same in either case. Now you're ready to copy the key to the server. Do so like this:

#### Example ####

user@homebox ~ $ ssh-copy-id -i ~/.ssh/id_dsa.pub user@'servername' (or 'ipaddress')

# If you are asked weather or not you wish to continue, say yes.

Step 5. Now it's time to test the setup. To do that, try to ssh to the server:

#### Example ####

user@homebox ~ $ ssh 'servername' (or 'ipaddress')

# You should log in to the remote host without being asked for a password.

Step 6. You can now SSH or SCP to the remote host without having to enter a password at each connection. To make sure your public key stays secure from prying eyes, do the following to change permissions and restrict access on 'homebox' and also on 'servername' to ~/.ssh:

#### Example ####

user@homebox ~ $ chmod 600 ~/.ssh/id_dsa ~/.ssh/id_dsa.pub

# Verify the permissions on the files:

#### Example ####

user@homebox ~ $ ls -l ~/.ssh
-rw------- 1 user user 668 Feb 4 19:26 id_dsa
-rw------- 1 user user 599 Feb 4 19:26 id_dsa.pub

Links

1. OpenSSH

2. known_hosts

3. fingerprint

------
Nice post!

I've noticed that I don't have the command ssh-copy-id on my OS X machine (I didn't even know one existed!). To achieve the same effect I usually do the following:
user@homebox ~ $ scp ~/.ssh/id_dsa.pub user@'servername':.ssh/authorized_keysThis is assuming you've already created a .ssh directory on your server 'servername' (just ssh in as normal and `mkdir .ssh`). This also assumes that you don't already have an `authorized_keys` file in the .ssh directory on your server. If you do just copy (scp) the id_dsa.pub file to a temporary file in your server's home directory and then
user@homebox ~ $ scp .ssh/id_dsa.pub user@servername:homebox_dsa.pubuser@homebox ~ $ ssh user@servernameuser@servername ~ $ cat homebox_dsa.pub >> .ssh/authorized_keysuser@servername ~ $ rm homebox_dsa.pub If you've got it, the ssh-copy-id way is clearly a lot easier!

~ Mark

Hi Mark. Thanks for adding that bit. I don't have access to a Mac (new one anyway) so that's very nice to know.

Seth

Seth, I liked this post a lot, but felt the formatting and wording can be improved. I've made a few changes to the introduction.

Xin
(I wish I had used my name for my username now!)

-------

I found an elegant way of creating a new, or adding to an existing authorized_keys file with a single command:

ssh username@somedomain.com -n "echo `cat ~/.ssh/id_dsa.pub` >> ~/.ssh/authorized_keys"-

I think it *is* a good practice to use pass phrases when using ssh keys. You can use ssh-agent on Linux and SSH Agent or SSHKeychain on Mac OS X, to avoid you to type your pass phrase everytime you access a remote host. Also, you can forward your keys using 'ssh -A' if you need to hop onto some host in the middle.

-- Igor
http://www.hostingrails.com/wiki/27/HowTo-SSHSCP-without-a-password

Two ways to copy files from a remote computer securely

Run any of the two following commands from the destination computer, previously located in the destination directory.

rsync -avz -e ssh root@192.x.x.x:/s01/backup/oradata/databkup/* .

scp root@192.x.x.x:/s01/backup/oradata/databkup/* .

After cloning a Linux box problems running vnc server, xterm can not run

After cloning a Linux box, running vnc server, a terminal connection could not start xterm. (I clonned a virtual server into a virtual server, on vmware ESX 3.5)
The log file (located at /home/username/.vnc/hostname:1.log) was as follows:

Wed Feb 11 11:27:53 2009
Client: Server default pixel format depth 16 (16bpp) little-endian rgb565
Client: Client pixel format depth 6 (8bpp) rgb222
xterm: Error 32, errno 2: No such file or directory
Reason: get_pty: not enough ptys


I think the two steps that solved it were:

1) create a new .Xauthority file
Loged in as username:
Delete the .Xauthority file, located at /home/username
Create a new .Xauthority file, issuing the command: $mkxauth -c

2) use makedev to create the pty and pts devices:
Loged in as root:

cd /dev
./MAKEDEV pty
./MAKEDEV ptm


Steps found at:

a) http://www.gelato.unsw.edu.au/IA64wiki/XinChroot

host:/# xterm
xterm: Error 32, errno 2: No such file or directory
Reason: get_pty: not enough ptys
try running MAKEDEV pty in /dev to make the devices you need.



b) http://mail-index.netbsd.org/pkgsrc-users/2008/07/09/msg007591.html


cannot start xterm on NetBSD-4.0

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

To: pkgsrc-users%netbsd.org@localhost
Subject: Re: cannot start xterm on NetBSD-4.0
From: Aleksey Cheusov
Date: Thu, 10 Jul 2008 00:46:55 +0300

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

>> - After manual running the following commands
>> cd /dev
>> ./MAKEDEV ptm
>> mkdir pts
>> mount pts

> You can add this to MAKEDEV under "init)":
> makedev ptm
> mkdir -m 0755 /dev/pts

I've added this code to /etc/rc.local (because /dev is on MFS)
and everything works fine now while booting.
But this is strange ;-( Before HDD failure everything worked fine
without this code.

>> xterm seems to work but says
>> utmp_update: Cannot update utmp entry: Resource temporarily unavailable
>> utmp_update: Cannot update utmp entry: Undefined error: 0

> Have you searched for "Cannot update utmp entry"? Same problem, same solution?
Thank you. I've found it :-) I really forgot -U option of build.sh

--
Best regards, Aleksey Cheusov.



I also made as root:

set DISPLAY=:0.0
export DISPLAY

Change name of server, after install SQL Server 2005

If you change the name of a server / computer, after installing SQL server 2005 (it happened to me also for SQL 7.0 server and SQL 2000 server), some of the programs that have access to the database, will have problems, because of the default instance was using the old name.
A long time ago, I had to backup my databases, uninstall SQL server, change the server name, reinstall SQL server, and restore the databases ....
But the solution is very simplistic: change the name of the server, and after restarting it, launch the SQL Management Studio (Enterprise Manager or Query Analyzer if using SQL server 2000), then execute the following queries:

1) select @@servername
It will show you the actual server name used by SQL server

2) sp_dropserver OLDNAME
GO
It will erase this parameter

3) sp_addserver NEWNAME, local
GO
It will configure the SQL server parameter with the new name

4) Restart SQL server services

5) select @@servername
It will show you the actual NEW server name used by SQL server. Try at least twice.

You're all done.
It works for the default instance.
If you need to read further, go to http://msdn.microsoft.com/en-us/library/ms143799.aspx

VMware virtual machines grayed out in Virtual Center

It happened to me already twice, with no apparent cause. Fortunately, the resolution is very straightforward, you just need to restart the management agents on ESX server.

Here is the link to VMware site:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003490

Here is the contents of it, so you can follow the procedure easily:

Restarting the Management agents on ESX Server 3.x

To restart the management agents on ESX Server 3.x:

1. Login to your ESX Server as root from either an SSH session or directly from the console of the server.
2. Type service mgmt-vmware restart .
   
   Caution: Ensure Automatic Startup/Shutdown of virtual machines is disabled before running this command or you risk rebooting the virtual machines. For more information, see Restarting hostd (mgmt-vmware) on ESX Server Hosts Restarts Hosted Virtual Machines Where Virtual Machine Startup/Shutdown is Enabled (1003312).
   
3. Press Enter.
4. Type service vmware-vpxa restart .
5. Press Enter.
6. Type logout and press Enter to disconnect from the ESX Server.

If this process is successful, it appears as:

[root@server]# service mgmt-vmware restart
Stopping VMware ESX Server Management services:
VMware ESX Server Host Agent Watchdog [ OK ]
VMware ESX Server Host Agent [ OK ]
Starting VMware ESX Server Management services:
VMware ESX Server Host Agent (background) [ OK ]
Availability report startup (background) [ OK ]
[root@server]# service vmware-vpxa restart
Stopping vmware-vpxa: [ OK ]
Starting vmware-vpxa: [ OK ]
[root@server]#

Restarting the Management agents on ESX Server 3i

To restart the management agents on ESX Server 3i:

1. Connect to the console of your ESX Server.
2. Press F2 to customize the system.
3. Login as root .
4. Using the Up/Down arrows navigate to Restart Management Agents.
5. Press Enter.
6. Press F11 to restart the services.
7. When the service has been restarted, press Enter.
8. Press Esc to logout of the system.

Command to delete user password under Linux

Type the following command to delete a user password:

# passwd --delete username

OR

# passwd -d username

Above command delete a user's password (make it empty). This is a quick way to disable a password for an account. It will set the named account passwordless. User will not able to login.

It is also a good idea to setup user shell to nologin to avoid security related problems:

# usrmod -s /sbin/nologin username

For example to delete password for user johnc, Type:

# passwd -d johnc
# usrmod -s /sbin/nologin johnc

Create a NFS share for VM ISO files with Windows 2003 Server R2

http://vmetc.com/2008/02/19/create-a-nfs-share-for-vm-iso-files-with-windows-2003-server-r2/

If your ESX servers are not connected to network storage or if you do not have enough available space on your SAN to dedicate a sub folder of a VMFS volume for ISO files, then you can use a NFS network share to centrally store these images. Creating the NFS share can be done with many server operating systems, but did you know that Windows Server 2003 R2 has native NFS?
VMware-land.com has many “how to” VMware Tips for ESX, and the following is the instructions found there for creating a Windows 2003 R2 NFS share:
window.google_render_ad();
On the Windows 2003 Server make sure “Microsoft Services for NFS” in installed. If not you need to add it under Add/Remove Programs, WindowsComponents, Other Network File and Print Services
Next go to folder you want to share and right-click on it and select Properties
Click on the NFS Sharing tab and select “Share this Folder”
Enter a Share Name, check “Anonymous Access” and make sure the UID and GID are both -2
In VirtualCenter, select your ESX server and click the “Configuration” tab and then select “Storage”
Click on “Add Storage” and select “Network File System” as the storage type
Enter the Windows Server name, the folder (share) name and a descriptive Datastore Name
Once it finishes the configuration you can now map your VM’s CD-ROM devices to this new VMFS volume
Repeat steps 5 through 8 for each of your ESX servers to make the same ISO files available to all ESX hosts.
These instructions assume that you have already configured the VMkernel port group on a vSwitch for each ESX host. For instructions and information about configuring the VMKernel for NAS/NFS storage check the Storage Chapter of the ESX Server 3 Configuration Guide.
Of course, you can use the NFS share for more than just ISO file storage too. This is a good repository for patches and scripts that need to be used on all hosts. NFS also makes a good target for VM image backups too. Use some imagination and install the free VMware server on your 2003 R2 box and you have a low budget DR platform. Oh yeah, I shouldn’t forget to mention you can even run ESX VMs from NFS!
Important Notes:
ESX version 3.x only supports NFS version 3 over TCP/IP.
Best practice for TCP/IP storage is to use a dedicated subnet. This will usually require creating separate Service Console and VMKernel port groups on a dedicated vSwitch.
On the Windows 2003 R2 server be sure to configure the shared folder so that the both the share and the file permissions allow everyone and anonymous full control. You can make the share read only when adding the storage in ESX.
Be sure to remember to punch a hole in the ESX firewall for NFS. On the Configuration tab, go to the Security Profile settings and add the NFS Client so it appears in the allowed outbound connections.


Important:
Dont forget the thing about windows 2003 security thing"On the Windows 2003 R2 server be sure to configure the shared folder so that the both the share and the file permissions allow everyone and anonymous full control. You can make the share read only when adding the storage in ESX." Then u will not be see this error:Error during the configuration of the host: Cannot open volume: /vmfs/volumes/********-********It took me avile to check that, and now i will spank myself around.