In linux you can set the date and time using either the timeconfig or linuxconf command utilities or simply by using the commands below
[root@server /root]# date 011711082008
Thu Jan 17 11:08:00 CDT 2008
[root@server /root]# hwclock –utc –systohc
[root@server /root]#
To survive a reboot, the “hwclock –utc –systohc” command is used to update the hardware clock with the date from the Linux system clock.
FTP have two types :
1. Active FTP and
2. Passive FTP.
Ftp session is a TCP session made up of two steps, the first connection on TCP port 21 known as a control connection and the second connection known as a data connection usually on TCP port 20. The issue arises when the second port is selected at random by applications and this data port is not always port 20.
Active FTP session:
In an Active FTP session the following steps occurs.
==> The client initiates the session from a random source port (Port X >1023) to the FTP server on TCP port 21.
2. The TCP Handshake will occur.
3. The client then sends the “FTP” port command from a source port (Port X+1) to the FTP server.
4.The server will then connect back from its local data port 20 to the client port (X+1)
Firewall issues for Active FTP session occurs on the client side as the FTP server tries to connect back to the client on TCP port 20 which is often blocked by the client Firewall.
Passive FTP Session:
In a passive FTP session the following steps occurs.
1. The client initiates the session from a random source port (Port X >1023) to the FTP server on TCP port 21.
2. The TCP Handshake will occur.
3. The client then sends the “PASV” port command from a source port (Port X+1) to the FTP server.
4. The server will then open one of its random ports (X >1023) and send this port X back to the client.
5. The client will then perform data transfer from its source port (PortX+1) to the FTP server port X.
Firewall issues for Passive FTP session occurs on the server side as the FTP server requires connection to a random data port instead of port 20 and the server side firewall will block this traffic.
Hello,
If your server have too many processes running for a single application here is the script that you can set in cron.
#!/usr/local/bin/perl
my $cmd=”ps -aef | grep -i java | grep -v grep | wc -l”;
$thread_count = `$cmd`;
chomp($thread_count);
$thread_count=~s/ //g;
$hostname=`hostname`;
print “thread count is $thread_count\n”;
if ($thread_count > 100){
print “inside the first 1f\n”;
for($flag = 0; $flag <=3;$flag++){
$mail =0;
$thread_count = `$cmd`;
chomp($thread_count);
$thread_count=~s/ //g;
print "thread count is $thread_count\n";
if ($thread_count > 100){
$mail = 1;
`sleep 180`;
}
}
}
print “Subject: Java Thread count high on $hostname\n”;
if ($mail == 1){
print “sending mail \n”;
open(MAIL, “|/usr/lib/sendmail -t”);
print MAIL “From: email\@domain.com\n”;
print MAIL “To: receiver\@domain.com,Nextreceiver\@domain.com\n”;
print MAIL “Subject: java Thread count high on $hostname\n”;
print MAIL “Open Deploy Thread count on $hostname value is $thread_count.\n\n”;
foreach (@output) {
chomp($_);
print MAIL “$_\n”;
}
close MAIL;
}
0,30 * * * * /script/process_moniter.sh
System-wide resources
* Run services under inetd/xinetd - Services such as SSH, SMTP servers, FTP servers, and almost any other service can be spawned by inetd/xinetd. In this case they only use memory when they are actually being used.
* Reduce the number of ttys started in your /etc/inittab:
#comment out lines like this
1:2345:respawn:/sbin/getty 38400 tty1
#2:2345:respawn:/sbin/getty 38400 tty2
#3:2345:respawn:/sbin/getty 38400 tty3
With Xen you can access only one real tty (tty1). Additional ttys like tty2, tty3 and so on are a waste of resources.
* Use ash or dash instead of bash. Be cautious! These alternative shells can break some scripts. Test all your scripts with the new shell before starting using it instead of bash.
[edit] MySQL
* Tune MySQL to use less memory for cache. The best is to use the my-small.cnf sample config as /etc/my.cnf. Below is an example of what to put in /etc/my.cnf.
[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
skip-locking
set-variable = key_buffer=16K
set-variable = max_allowed_packet=1M
set-variable = thread_stack=64K
set-variable = table_cache=4
set-variable = sort_buffer=64K
set-variable = net_buffer_length=2K
* MySQL uses 10MBs of RAM for InnoDB tables. Remove support for InnoDB tables if you do not use them. To remove support for InnoDB, put the following lines in /etc/my.cnf
[mysqld]
skip-innodb
[edit] Apache/PHP
* Tune Apache to only have a small number of spare children running. An example of the Apache configuration section:
StartServers 1
MinSpareServers 1
MaxSpareServers 5
ServerLimit 64
MaxClients 64
MaxRequestsPerChild 4000
Also, only load the modules you require. If you do do not use PHP, mod_perl, etc then do not install them.
* Install a PHP Cache such as Alternative PHP Cache. The PHP cache will store compiled PHP scripts so that they can be reused without the overhead of compiling and processing them for each request.
Stop Windows from saving the thumbnail cache (THUMBS.DB)
Intended For: Windows Vista Windows XP Windows 2003
Windows XP, by default, shows the thumbnails view of certain folders, whether you want it to or not. Even if you choose Details (or some other view) as your default by going to Tools -> Folder Options -> View tab and click Apply to All Folders, Explorer may still revert back to the clumsy Thumbnails view. It does this for any folder in which it finds the THUMBS.DB file; naturally, if you delete this file, it won’t happen again.
The problem is that Windows seems to repeatedly recreate the THUMBS.DB file automatically. Here’s how to stop this from happening:
1. In Explorer, go to Tools -> Folder Options or open the Folder Options icon in the Control Panel.
2. Choose the View tab, and turn off the Do not cache thumbnails option.
3. Click Ok.
You can also change this setting in the Registry:
1. Open the Registry Editor (regedit.exe).
2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced.
3. Double-click the DisableThumbnailCache value, or go to Edit -> New -> DWORD value to create a new value by that name.
4. Enter 1 for its value.
5. Click Ok and close the Registry Editor when you’re done; you’ll have to log off and then log back on for this to take effect.
Oracle SQL*Net Listener
Allows Oracle client connections to the database over Oracle’s SQL*Net protocol. You can configure it during installation. To reconfigure this port, use Net Configuration Assistant.
1521
I want to use a default mail address of
*: :fail: No such address
… in a domain’s valias file. Easy enough to do but I still want to let through postmaster@domain.com and abuse@domain.com as per common practice. Some servers for instance will not allow mail through if there is no postmaster@… defined for a domain, Sourceforge being an example.
Here’s a solution:
1. Create a file called /etc/myaliases with:
Code:
postmaster: root
abuse: root
2. In the WHM > Exim Configuration Editor scroll down to the section “DIRECTORS CONFIGURATION” and in the first text box of that section put:
Code:
mysystem_aliases:
driver = redirect
allow_defer
allow_fail
data = ${lookup{$local_part}lsearch{/etc/myaliases}}
file_transport = address_file
pipe_transport = address_pipe
retry_use_local_part
You’ll then have a server-wide postmaster and abuse address that won’t be interfered with by users having :fail: Default Addresses.
Here is the script which allows you to include the login script anywhere and still catch incorrect logins and redirect them to your website.
Hope this helps someone.
Code: dpcpanellogin.php
Code: include_anywhere.php
Just include the code in include_anywhere.php inside your page and place the docpanellogin.php file in the same directory. The rest should work
The reason why this script was written was because we have too many servers and its very hard to come back each time to the script and insert the new server name. Instead here we just take the domain from the user. Anyone who wants to embed the domain name should replace the following lines from include_anywhere.php
Code:
input name=”domain” type=”text” value=”"
and replace with
Code:
input name=”domain” type=”hidden” value=”YOUR_SERVER_NAME”
replacing the “YOUR_SERVER_NAME” with your server name. (I haven’t test this part but it should work )
Greetings!
That is because Tomcat is not compiled with APR (Apache Runtime Portable) Module and it is not require cause that module is not going to affect tomcat performance. It is just an INFO: message and you won’t need to worry about that. You should be able to start tomcat once you get that message.
Regards,
Darsh
lsmod
lsmod lists the modules loaded by the Linux kernel.
modprobe
modprobe loads a Linux kernel module. You can specify only the name of the module, and modprobe will load it from the correct location and also load any dependent modules.
Many modules load automatically. For example, Linux loads a USB keyboard module when a USB keyboard is attached. It also loads the base USB modules as dependencies. Some modules must be loaded manually, and “modprobe” is the easiest way to do this.
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
e.g.
# modinfo nfs
filename: /lib/modules/2.6.9-42.ELhugemem/kernel/fs/nfs/nfs.ko
author: Olaf Kirch
license: GPL
vermagic: 2.6.9-42.ELhugemem SMP 686 REGPARM 4KSTACKS gcc-3.4
depends: sunrpc,nfs_acl,lockd
# modprob -a MODULE_NAME #add module
#modprob -r MODULE_NAME #removes module DO NOT USE IF YOU DO NOT KNOW