Syed Jahanzaib Personal Blog to Share Knowledge !

August 30, 2012

Vmware ESXi 5.0 Update1 Autostart breakup Fix !

Filed under: VMware Related — Syed Jahanzaib / Pinochio~:) @ 4:19 PM

In my company, we have two virtual servers based on Microsoft Hyper-V & Free version of ESXi 4.0 running 10 guest OS. We did planned to convert all of our physical machine to virtual to get benefit from underutilized modern hardware. Last week I decided to move our Domain Controller & ADC to virtual (which were installed on IBM Xseries physical serve machines).

As a rule of thumb, always test any new / trial product in LAB before deploying it on production server, following this theory I installed Vmware ESXi 5.0 Update 1 on vmware workstation 7.x and found out a BUG that guest vm’s do not auto start anymore when the host ESXi starts (In previous versions i.e 4.x , they auto start normally if they are set to autostart). This is a bug for the FREE version of the hypervisor. (For example if you have installed the FREE License key provided by vmware)

After some googling, I found out that There were some changes made in the way the ESXi APIs are accessed in Update 1 that unfortunately breaks the Guest VM Auto Start feature.

Here is a quick workaround to give you the autostart functionality in traditional Linux style.

If you haven’t done so already, Do Enable SSH on the ESXi host server. This can be easily done using Sphere client.

  • Connect to ESXI using Vsphere client.
  • Goto Configuration Tab | Security Profile | in Services, click on Properties
  • Highlight SSH | Select Options | Service Commands | Start
  • Use any SSH client like PuTTY) to log into your host server. As showed in the image below

In my case, I only wanted to auto start only single guest vm  (Which is my test DC)  So first We need to get the VM ID’s for the virtual machines. Use the following command to do so. Make note of the ID numbers in the first column

Use the following command to get the VM ID of the machine you want to start.

vim-cmd vmsvc/getallvms

You will get results something like below ( I only have one test machine, so only one entry is visible)

Vmid          Name                                File                               Guest OS         Version   Annotation
1      TestPC-4-Autostart   [store] TestPC-4-Autostart/TestPC-4-Autostart.vmx   win2000AdvServGuest   vmx-08

The VM ID for test pc guest OS is 1

Use vi to edit /etc/rc.local  – & Insert the following startup lines above the IF statement and save.

vim-cmd vmsvc/power.on 1

[VI TIP: to enable editing, press i , now add your lines, to save, press ESC, now press shift+: & type wq and press enter]
As showed in the image below . . .

Save & Exit.

Now reboot the ESXi host server.

After reboot completes, you will see the target guest OS Auto starting this time.

Auto Start All VM’s guest OS

TIP: If you want to start all vm’s you need to add them as follow

vim-cmd vmsvc/power.on 1
sleep 180
vim-cmd vmsvc/power.on 2
sleep 180
vim-cmd vmsvc/power.on 3
sleep 180

Change the ID number as per your configuration. Now after starting 1st VM, ESXi HOST will wait 180 Seconds (3 minutes) to start second one and so on. You can change this number as per your hardware/software load.

I hope you will find it useful.


Syed Jahanzaib

Windows 2003 x86 3 GB RAM limitation

Recently we did some memory upgrade on one of our server pc. It had 2 GB of RAM and we upgrade it to 6 GB . As you know, 32 bit (known as x86) Operating System only support 3.2 GB RAM maximum. After installing RAM into system, In the BIOS it showed correct amount of memory, but in Windows OS (32bit) it shows only 3.2 GB of RAM as showed in the image below.

To fix this issue, add the following syntax at the end in boot.ini [(found in c:\) , in [operating systems] section.


For example

Windows 2003 boot.ini sample

[boot loader]
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /noexecute=optout /fastdetect /PAE

Save & exit. Now reboot the system and this time, you will see proper result. as showed in the image below

Syed Jahanzaib

August 24, 2012

Squid don’t cache IDM downloads ?

Filed under: Linux Related — Tags: , , — Syed Jahanzaib / Pinochio~:) @ 4:49 PM

I was having a problem that if a user download any file like .exe using IDM, it never cached by squid proxy, So I did some digging and found out that IDM was splitting the file into multiple pieces and requesting each of those pieces as different HTTP requests & the Squid cannot cache partial files by default, only whole file can be cached.
As you can clearly see in the below image that  no matter how many times I download the same file using IDM, it always show TCP_MISS in the squid access logs.

Downloads via IDM always MISS


I solved this by adding following two directives in squid.conf and then restart squid service.

range_offset_limit -1

Now I again downloaded the file twice using IDM, and this time I can see TCP_HIT and the cache hit worked like a charm. As showed in the image below.

Downloads via IDM gets HIT after tunning squid.conf


CAUTION:Use this directive with care, because in some cases it can give you undesirable results including excessive bandwidth usage, e.g: If a user starts downloading any file of any size , lets suppose 600 MB, and he cancel the download in middle or after 10MB, the  SQUID will continue to download the whole file in the cache. This will cause a bigger problem , if user downloading a file with
download manager ,let’s say in 6 segments , squid will start 6 download threads for the same file each one from its beginning. & it will  consume 6 times bandwidth than really needed. so it can really become bottleneck in some cases, specially if you have small bandwidth pipe.So be careful using this option.  Most people prefer the opposite, to make Squid abort downloads immediately.because this kind of continued downloads can easily chew up a considerable amount of bandwidth for a very log hit ratio.

Syed Jahanzaib

August 13, 2012

Youtube caching with Squid + Nginx

Filed under: Linux Related — Tags: , , — Syed Jahanzaib / Pinochio~:) @ 11:52 AM

Updated Version of squid which cache youtube and many other contents. read following



Advantages of Youtube Caching   !!!

In most part of the world, bandwidth is very expensive, therefore it is (in some scenarios) very useful to Cache Youtube videos or any other flash videos, so if one of user downloads video / flash file , why again the same user or other user can’t download the same file from the CACHE, why he sucking the internet pipe for same content again n again?
Peoples on same LAN ,sometimes watch similar videos. If I put some youtube video link on on FACEBOOK, TWITTER or likewise , and all my friend will  watch that video and that particular video gets viewed many times in few hours. Usually the videos are shared over facebook or other social networking sites so the chances are high for multiple hits per popular videos for my LAN users / friends. [syed.jahanzaib]

This is the reason why I wrote this article.

Disadvantages of Youtube Caching   !!!

The chances, that another user will watch the same video, is really slim. if I search for something specific on youtube, i get more then hundreds of search results for same video. What is the chance that another user will search for the same thing, and will click on the same link / result? Youtube hosts more than 10 million videos. Which is too much to cache anyway. You need lot of space to cache videos. Also accordingly you will be needing ultra modern fast hardware with tons of  SPACE to handle such kind of cache giant. anyhow Try it

AFAIK you are not supposed to cache youtube videos, youtube don’t like it. I don’t understand why. Probably because their ranking mechanism relies on views, and possibly completed views, which wouldn’t be measurable if the content was served from a local cache.

After unsuccessful struggling with method , I was searching for alternate method to cache youtube videos. Finally I found ruby base method using Nginx to cache YT. Using this method I was able to cache all Youtube videos almost perfectly. (not 100%, but it works fine in most cases with some modification.I am sure there will be some improvement in near future).

Updated: 24thth August, 2012

Thanks to Mr. Eliezer Croitoru & Mr.Christian Loth & others for there kind guidance.

Following components were used in this guide.

Proxy Server Configuration:
Ubuntu Desktop 10.4
Nginix version: nginx/0.7.65
Squid Cache: Version 2.7.STABLE7

Client Configuration for testing videos:
Windows XP with Internet Explorer 6
Windows 7 with Internet Explorer 8

Lets start with the Proxy Server Configuration:

1) Update Ubuntu

First install Ubuntu, After installation, configure its networking components, then update it by following command
apt-get install update

2) Install SSH Server [Optional]

Now install SSH server so that you can manage your server remotely using PUTTY or any other ssh tool.

apt-get install openssh-server

3) Install Squid Server

Now install Squid Server by following command
apt-get install squid
[This will install squid 2.7 by default]

Now edit squid configuration files by using following command

nano /etc/squid/squid.conf

Remove all lines and paste the following data

# Email:
# Web  :
# PORT and Transparent Option
http_port 8080 transparent
server_http11 on
icp_port 0

# Cache is set to 5GB in this example (zaib)
store_dir_select_algorithm round-robin
cache_dir aufs /cache1 5000 16 256
cache_replacement_policy heap LFUDA
memory_replacement_policy heap LFUDA

# If you want to enable DATE time n SQUID Logs,use following
emulate_httpd_log on
logformat squid %tl %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt
log_fqdn off

# How much days to keep users access web logs
# You need to rotate your log files with a cron job. For example:
# 0 0 * * * /usr/local/squid/bin/squid -k rotate
logfile_rotate 14
debug_options ALL,1
cache_access_log /var/log/squid/access.log
cache_log /var/log/squid/cache.log
cache_store_log /var/log/squid/store.log

#[zaib] I used DNSAMSQ service for fast dns resolving
#so install by using "apt-get install dnsmasq" first

#ACL Section
acl all src
acl manager proto cache_object
acl localhost src
acl to_localhost dst
acl SSL_ports port 443 563 # https, snews
acl SSL_ports port 873 # rsync
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 563 # https, snews
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl Safe_ports port 631 # cups
acl Safe_ports port 873 # rsync
acl Safe_ports port 901 # SWAT
acl purge method PURGE
http_access allow manager localhost
http_access deny manager
http_access allow purge localhost
http_access deny purge
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access allow all
http_reply_access allow all
icp_access allow all

#[zaib]I used UBUNTU so user is proxy, in FEDORA you may use use squid
cache_effective_user proxy
cache_effective_group proxy

cache_mem 8 MB
minimum_object_size 0 bytes
maximum_object_size 100 MB
maximum_object_size_in_memory 128 KB

refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern (Release|Packages(.gz)*)$ 0 20% 2880
refresh_pattern . 0 50% 4320
acl apache rep_header Server ^Apache
broken_vary_encoding allow apache

# Youtube Cache Section [zaib]
url_rewrite_program /etc/nginx/nginx.rb
url_rewrite_host_header off
acl youtube_videos url_regex -i ^http://[^/]+\.youtube\.com/videoplayback\?
acl range_request req_header Range .
acl begin_param url_regex -i [?&]begin=
acl id_param url_regex -i [?&]id=
acl itag_param url_regex -i [?&]itag=
acl sver3_param url_regex -i [?&]sver=3
cache_peer parent 8081 0 proxy-only no-query connect-timeout=10
cache_peer_access allow youtube_videos id_param itag_param sver3_param !begin_param !range_request
cache_peer_access deny all

Save & Exit.

4) Install Nginx

Now install Nginix by
apt-get install nginx

Now edit its config file by using following command
nano /etc/nginx/nginx.conf

Remove all lines and paste the following data

# This config file is not written by me, [syed.jahanzaib]
# My Email address is inserted Just for tracking purposes
# For more info, visit
# Syed Jahanzaib / aacable [at]
user www-data;
worker_processes 4;
pid /var/run/;
events {
worker_connections 768;
http {
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
gzip on;
gzip_static on;
gzip_comp_level 6;
gzip_disable .msie6.;
gzip_vary on;
gzip_types text/plain text/css text/xml text/javascript application/json application/x-javascript application/xml application/xml+rss;
gzip_proxied expired no-cache no-store private auth;
gzip_buffers 16 8k;
gzip_http_version 1.1;
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
# starting youtube section
server {
location / {
root /usr/local/www/nginx_cache/files;
#try_files "/id=$arg_id.itag=$arg_itag" @proxy_youtube; # Old one
#try_files  "$uri" "/id=$arg_id.itag=$arg_itag.flv" "/id=$arg_id-range=$arg_range.itag=$arg_itag.flv" @proxy_youtube; #old2
try_files "/id=$arg_id.itag=$arg_itag.range=$arg_range.algo=$arg_algorithm" @proxy_youtube;
location @proxy_youtube {
proxy_pass http://$host$request_uri;
proxy_temp_path "/usr/local/www/nginx_cache/tmp";
#proxy_store "/usr/local/www/nginx_cache/files/id=$arg_id.itag=$arg_itag"; # Old 1
proxy_store "/usr/local/www/nginx_cache/files/id=$arg_id.itag=$arg_itag.range=$arg_range.algo=$arg_algorithm";
proxy_ignore_client_abort off;
proxy_method GET;
proxy_set_header X-YouTube-Cache "";
proxy_set_header Accept "video/*";
proxy_set_header User-Agent "YouTube Cacher (nginx)";
proxy_set_header Accept-Encoding "";
proxy_set_header Accept-Language "";
proxy_set_header Accept-Charset "";
proxy_set_header Cache-Control "";}

Save & Exit.

Now Create directories to hold cache files

mkdir /usr/local/www
mkdir /usr/local/www/nginx_cache
mkdir /usr/local/www/nginx_cache/tmp
mkdir /usr/local/www/nginx_cache/files
chown www-data /usr/local/www/nginx_cache/files/ -Rf

Now create nginx .rb file

touch /etc/nginx/nginx.rb
chmod 755 /etc/nginx/nginx.rb
nano /etc/nginx/nginx.rb

Paste the following data in this newly created file

#!/usr/bin/env ruby1.8
# This script is not written by me,
# My Email address is inserted Just for tracking purposes
# For more info, visit
# Syed Jahanzaib / aacable [at]
# url_rewrite_program <path>/nginx.rb
# url_rewrite_host_header off

require "syslog"
require "base64"

class SquidRequest
attr_accessor :url, :user
attr_reader :client_ip, :method

def method=(s)
@method = s.downcase

def client_ip=(s)
@client_ip = s.split('/').first

def read_requests
# URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
STDIN.each_line do |ln|
r =
r.url, r.client_ip, r.user, r.method, *dummy = ln.rstrip.split(' ')
(STDOUT << "#{yield r}\n").flush

def log(msg)
Syslog.log(Syslog::LOG_ERR, "%s", msg)

def main'nginx.rb', Syslog::LOG_PID)

read_requests do |r|
if r.method == 'get' && r.url !~ /[?&]begin=/ && r.url =~ %r{\Ahttp://[^/]+\.youtube\.com/(videoplayback\?.*)\z}
log("YouTube Video [#{r.url}].")

Save & Exit.

5) Install RUBY

What is RUBY?
Ruby is a dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write. [syed.jahanzaib]

Now install RUBY by following command

apt-get install ruby

6) Configure Squid Cache DIR and Permissions

Now create cache dir and assign proper permission to proxy user

mkdir /cache1
chown proxy:proxy /cache1
chmod -R  777 /cache1

Now initialize squid cache directories by

squid -z

You should see Following message

Creating Swap Directories

7) Finally Start/restart SQUID & Nginx

service squid start
service nginx restart

Now from test pc, open youtube and play any video, after it download completely, delete the browser cache, and play the same video again, This time it will be served from the cache. You can verify it by monitoring your WAN link utilization while playing the cached file.

Look at the below WAN utilization graph, it was taken while watching the clip which is not in cache

WAN utilization of Proxy, While watching New Clip (Not in cache)

Now Look at the below WAN utilization graph, it was taken while watching the clip which is now in CACHE.

WAN utilization of Proxy, While watching already cached Clip

Playing Video, loaded from the cache chunk by chunk

It will load first chunk from the cache, if the user keep watching the clip, it will load next chunk at the end of first chunk, and will continue to do so.

Video cache files can be found in following locations.


ls -lh /usr/local/www/nginx_cache/files

The above file shows the clip is in 360p quality, and the length of the clip is 5:54 Seconds.
itag=34 shows the video quality is 360p.

Credits: Thanks to Mr. Eliezer Croitoru & Mr.Christian Loth & others for there kind guidance.

Find files that have not been accessed from x days. Useful to delete old cache files that have not been accessed since x days.

 find  /usr/local/www/nginx_cache/files  -atime  +30  -type f

Syed Jahanzaib

August 3, 2012

The Dude: Configuring Voice Alert Notification

Filed under: Mikrotik Related — Tags: , , , , — Syed Jahanzaib / Pinochio~:) @ 10:36 AM

Howto Configure Dude Voice Notification

Double Click on your desired device on the map ,
Goto Services Tab,
Select Your Desired Service on which you want Voice Alert, For Example if you want that if server is not responding, it should alert you via voice , Double Click on PING probe,
Goto Notifications tab,
Select Check on Use Notifications
Select check on VOICE
Click Ok

As shown in the image below . . .

It uses Windows Built in TTS (Text to Speech) tool to make voice (accent is Microsoft’s ANNA) but you can select other voice format files like .wav.

Now test it by disable LAN interface on target device, after 1-2 minutes when device appears RED, it will alert you with Voice. However the lady take long time to describe the problem due to various text alerts inside the voice notificaiton, some time it becomes annoying if you have lot of voice alerts, so its better to trim the VOICE notification, by going to voice notification and take properties on VOICE notification and cut down un.necessary functions. e.g

ALERT, [Device.Name], [Probe.Name], is now, [Service.Status],,,
You can also select multiple voice alert notification for various devices functions. For example I monitor my DSL internet connectivity by adding on map. So when the timeouts due to internet connectivity lost, it give me voice alert like

“Alert, Internet connectivity have been lost”
& when the connectivity restores,
“Internet connectivity have been restored”

For this you have to create two different notifications, one that has unstable->down enabled for one wave file andanother notification with down->up for the other wave file.  [Special Thanks to Mr. Lebowski for this tip @ forums]


For more information, please visit following link.


Syed Jahanzaib

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