How to enable ftp on VirtualBox

You can transfer file from your local machine to virtual box via shared folders or via ftp.

By default looks like ftp is blocked on Virtual Box

Just inside your guest O/S i.e. VirtualBox Linux go to

/etc/xinetd.d/

and modify gssftp file

Change from ‘Yes’ to ‘No’ for DISABLE column as shown in below screenshot and remove value against “server_args”

ftp

 

 

 

 

 

You can restart ftp service via following command

/etc/init.d/xinetd restart

 

Categories: Linux, Oracle blogroll, Unix Tags: ,

How to check if Linux version is 32 bit or 64 bit

You can use following methods

Use this command getconf LONG_BIT

or use this on unix prompt

uname -m

Categories: Linux, Unix Tags: , ,

Setting up swapspace for Oracle

Sometime we land up in a situation where we have to increase swap space, since Oracle installation expects a certain % of swap space depending upon how much RAM you have allocated to O/S. For example if we have allocated 64 mb of RAM, then we need to specify 128 mb of swap space… again this is not always the case that you have to specify swapsize twice of RAM. It all depends on the OS etc, generally here is a little thumb rule

If you have between 1 and 2G RAM, you need to configure 1.5x RAM for swap space.
For 2 to 8G RAM, swap space has to equal RAM.
For RAM more than 8G, swap needs to be ¾ RAM.

If we need to ad swaps pace, we can either add a new partition of type swap or else we can file which can be used by O/S to be used as swap. I am going to demostrate adding swap space via adding file

How to check how much swapsize is specified via following command ?

# swapon -s

or

# cat /proc/meminfo

If I need to add swap space of let’s say 2 gb, i can issue following ‘dd‘ command

# dd if=/dev/zero of=/swapfile bs=1024 count=2097152

Count 2097152 is calculated via multiplying bs or blocksize of 1024 * 2048 mb

Where,

1) if=/dev/zero : Read from /dev/zero file. /dev/zero is a special file in that provides as many null characters to build storage file called /swapfile.
of=/swapfile : Read from /dev/zero write stoage file to /swapfile.
2) bs=1024 : Read and write 1024 BYTES bytes at a time.
3) count=2097152 : Copy only 2097152 BLOCKS input blocks.

The following command will setup the swap space

# mkswap /swapfile

Activate it via

# swapon/swapfile

There is one small thing still pending, once you reboot the Linux server this information is lost, in order to make it more permanent, we need to add following in /etc/fstab file, this file is primarily responsible for telling Linux that what all devices to mount, just add following line in fstab ( File System Table )

/swapfile               swap                    swap    defaults        0 0

Announcing Oracle Enterprise Manager 12c

January 12, 2012 Leave a comment

Learn about Oracle’s unique approach to cloud management, and see how Oracle helped its customers provision applications 84% faster, reduce time-to-resolution of service requests by 50% and easily manage user experiences for millions of customers.

Larry Ellison Open World Key Note – 5th Oct 2011

How to Drop Oracle Database ?

September 14, 2011 Leave a comment

CAUTION : DO NOT PERFORM THIS OPERATION IN YOUR PRODUCTION DATABASE FOR TESTING PURPOSE 🙂

With Oracle 10g release, Oracle Inc. has provided a sql command to Drop Database. Prior to Oracle 10g, the DBA had to physically delete the relevant files ( such as data files, control files, online redo log files & spfile )used by Oracle Database.

To drop the database, before even connecting the SQL prompt , make sure you have specified correct ORACLE_SID. You do not want to drop another db by accident.

Once you have specified/verified correct ORACLE_SID variable, now you need to shutdown the database via sql

SQL> Shutdown immediate;

Now, you need to to bring the database in exclusive restrictive mount mode

SQL> startup mount exclusive restrict;

Mount Database in exclusive restrict mode
Now just issue the drop database command

SQL> drop database;

Drop Database

NOTE : You can also perform whole of this activity via GUI utility provided by Oracle which is called dbca ( search for binary dbca in $ORACLE_HOME/bin dir) . That utility will behind the scenes take care of starting db in mount restrict mode & then based on your selection of db that you would want to drop, it will do so.

In case this activity was performed on windows server, then you need to also execute following command to remove service

oradim -DELETE -SID <name of instance>

 

All you need to know about the Oracle ACE program !!

September 11, 2011 Leave a comment
  • More information about ACE listed here …

  • Categories: ACE, Oracle blogroll Tags: