Difference Between Ext2, Ext3 & Ext4.

Ext stands for Extended file system. In this article we can discuss about difference between ext2, ext3 & ext4 file systems in linux and specification for each file system.Ext2 file system is default file system in linux.
Ext2(Extended 2 file system )
Ext3(Extended 3 file system )
Ext4(Extended 4 file system )
This was developed to overcome the limitation of the original ext file system.
The main benefit of ext3 is that it allows journaling. Journaling has a dedicated area in the file system, where all the changes are tracked. When the system crashes, the possibility of file system corruption is less because of journaling.
The ext4 file system has major improvements in terms of performance, scalability, and reliability.
Maximum individual file size can be from 16 GB to 2 TB
Overall ext2 file system size can be from 2 TB to 32 TB
Maximum individual file size can be from 16 GB to 2 TB
Overall ext2 file system size can be from 2 TB to 32 TB
support files and file systems of up to 16 terabytes in size
You can’t convert a ext2 file system to ext3 file system
You can convert a ext2 file system to ext3 file system directly (without backup/restore).
You can convert a ext3 file system to ext4 file system directly
Ext2 faster than ext3
prevent filesystem corruption in the case of an unclean shutdown, That makes ext3 a bit slower than ext2
. Ext4 uses extents , which improves performance when using large files and reduces metadata overhead for large files
it has sparse super blocks feature which increase file system performance
But ext3 gets more reliability and a better performance
The ext4 file system, often waits several seconds to write out changes to disk, allowing it to combine and reorder writes for better disk performance than ext3
Ext2 will not provide a fast recovery from disk problems
allows fast recovery from disk problems
ext4 also labels unallocated block groups and inode table sections accordingly, which allows them to be skipped during a file system check. This makes for quicker file system checks, which becomes more beneficial as the file system grows in size.

 

Published By

S.G.Godwin Dinesh.MCA

Sr.System Administrator

How to save your data from getting corrupted

some tips to save your data from getting corrupted:-

• Data loss – whether from hardware failure, digital corruption, or even accidental deletion – is a hard, yet inevitable truth in this age of computers.
• But you can take simple precautions to protect important documents and e-mails, photographs, music files and videos. Your Windows OS comes with tools that will help you take a backup; your external hard drive comes with backup software. Yet, despite best intentions we fail to create copies of our files. It’s probably because the process might seem daunting. Well, its not…

1. Local storage:-

• The quickest place to save a backup of your data is on the hard disk in your PC. Here, however, you will first need to ensure that your copies are stored on a separate physical drive in your machine. A note of caution: different partitions do not mean different drives. In the event of a hard drive failure, you will lose all your data if your files were stored on the same disk, even though it might show as a different drive letter on your system.
• Now, given current drive capacities, most PCs come with just a single hard drive. In this case, it would be best to invest in an external hard disk. As mentioned earlier, each brand comes with its own backup utility. Follow the simple steps to back up your files at regular intervals. Tip: Till you get into an ‘automatic’ habit, create a reminder on your phone that will prompt you to backup every weekend.

2. Personal cloud storage:-

• While a local backup is a good idea, an online repository for your documents, music and pictures will give you the freedom to access them from any web-enabled device. Besides, many cloud services come with mobile apps, allowing you to access, synchronize and share files on the go.

3. Dropbox :-

• This service gives you 2GB of free storage. If you suggest it to friends, you can earn up to 18GB of space.
• Dropbox also has software for Windows, Mac and Linux PCs, and apps for Android, BlackBerry, and iOS devices. To back up a file, place it in the local Dropbox folder on your PC and it will be pushed online, showing up on your smartphone as well.

4. Google Drive :-

• Google Drive offers up to 15GB of free space which is shared across Gmail and Google+ services. While Drive is not ideal for multimedia file storage, it is perfect for documents, with support for over thirty formats that can be opened within the mobile app – available for Android and iOS – or the web browser.

5. Box :-

• With 10GB of storage space, you will have more than enough room for backing up personal and work-related documents. If you are not into taking your photographs public on Flickr and Picasa, you can store them on Box.
• Entire folders can be shared with friends and family, turning the backup process into an advantage. Just make sure you don’t give write access to those with whom you share the folder. Besides mobile apps for Android and iOS devices, Box also works on Windows Phone.

6. SkyDrive :-

• With SkyDrive, you get 7GB of free space and the ability to work on documents within a web browser or its app that’s available for Android, iOS and Windows Phone.
• This service works well with photos too: it comes with a slideshow function and supports sharing on social networks.

7. Mega :-

• Mega tops ours charts with a whopping 50GB of free storage space. It is a pure-bred digital locker with AES-128 encryption for all your data. As of now, the service can be accessed via your PC and through an app for Android. iOS and Windows Phone offerings are in the works.

8. Backing up with Windows:-

• You can also use the built-in backup and restore utility in Windows. The best part is that you can schedule and automate the entire process with the help of a simple wizard.

(1) In Windows 7

Click Start > Control Panel > System and Maintenance > Backup and Restore. Here, you are presented with two options 1 Make a full backup of the system: In the left pane, click Create new, full backup. 2 Customize the archival: Click Set up backup and then follow the wizard to configure what you want to make a copy of. After that first time, whenever you bring up Back and Restore, just click Back up now. To restore your data, double-click the backup file to start the process. Alternatively, open Backup and Restore > Restore my files. Browse through the backup and choose the files and folders you want to restore; select the destination and click Restore.

(2) In Windows 8.1

Connect an external hard drive to your PC. Then, using your cursor, point to the upper right corner of the screen. In the ‘charms’ bar that appears, click on the Search option and type File History to access it. Enable the File History option and follow the instructions to select the folders you want to backup. You can restore files from earlier copies with the same utility.

Published By:

S.G.Godwin Dinesh.MCA
Sr.System Administrator

Windows Server Migration Tools

You can install Windows Server Migration Tools by using the Windows PowerShell cmdlet Add-WindowsFeature for Server Manager.

To install Windows Server Migration Tools on a full installation of Windows Server 2008 R2

Open a Windows PowerShell session with elevated user rights. To do this, click Start, click All Programs, click Accessories, click Windows PowerShell, right-click the Windows PowerShell shortcut, and then click Run as administrator.

1. Load the Server Manager module into your Windows PowerShell session. To load the Server Manager module, type the following, and then press Enter.

3.  Import-Module ServerManager

4. Type the following, and then press Enter.

5.  Add-WindowsFeature Migration

Note

You can also install Windows Server Migration Tools on a full installation of Windows Server 2008 R2 by using the Server Manager console. For more information about how to use the Server Manager console, see Adding Server Roles and Features in the Server Manager Help on the Microsoft Web site (http://go.microsoft.com/fwlink/?LinkId=134104).

6. To migrate Hyper-V or Routing and Remote Access Services to Windows Server 2008 R2, you must also do the following:
1. Download the Windows Server 2008 R2 Migration Utilities package on the local computer that is running Windows Server 2008 R2. The download package is available on the Microsoft Web site (http://go.microsoft.com/fwlink/?LinkId=178389).
2. In the Windows PowerShell session opened in step 1, install Windows Server 2008 R2 Migration Utilities by typing the following command, in which Path represents the fully-qualified path to the package, and then press Enter.

3.  \Windows6.1-KB977336-v2-x64.msu

4. Follow the instructions in the Installation Wizard to complete installation.
5. Restart the computer after the installation of Windows Server 2008 R2 Migration Utilities is finished.

Source:

www.technet.microsoft.com

Published By

S.G.Godwin Dinesh.MCA

Sr.System Administrator

 

How to configure the RBL Filter

The RBL Filter implemented in BitDefenderSecurity for Windows Servers uses the DNSBL protocol and RBLservers to filter spam based on mail server's reputation as spam senders.

In order to configure the RBLFilter you need to perform the following actions:

1. Open BitDefender and go to the Antispam module;
2. In the right-hand side of the MMC console click GlobalFilters...;
3. Choose Real-time Blackhole List;
4. Enter your organization DNS server in the DNS IP oraddress field;
5. Choose the desired query timeout;
6. Click Add Server... to add the RBL servers; you
   will be prompted for the server information and the trust level for each server;
7. Click OK to finish adding the RBL server.
8. Enable the RBL filter by opening Bitdefender Security for Mail Servers and going to Antispam -> Policies, then double click the current rule. Go to Antispam Engines -> Enable RL Filter

Published By

S.G.GodwinDinesh.MCA
Sr.System Administrator

Full Form of Netwroking Devices & CCNA

FULL FORM OF COMPUTER HARDWARE AND NETWORKING DEVICES FREE

IN FREETEACHINGS NOW YOU WILL READ THIS FULL FORM OF NETWORKING DEVICES  N+ or A+ exam you may have a question asking for full form.please read this full form all networking devices Beside exam in networking world we have to face several situation where need the extended or complete form of abbreviated form. Here we tried to list few most of them with their full form.full form of all computer devices and networking free readable please read this.

AC	alternating current
ACPI	advanced configuration and power interface
ACT	activity
ADSL	asymmetrical digital subscriber line
AGP	accelerated graphics port
AMD	advanced micro devices
AMR	audio modem riser
APIPA	automatic private internet protocol addressing
APM	advanced power management
ARP	address resolution protocol
ASR	automated system recovery
AT	advanced technology
ATA	advanced technology attachment
ATAPI	advanced technology attachment packet interface
ATM	asynchronous transfer mode
ATX	advanced technology extended
BIOS	basic input/output system
BNC	Bayonet-Neill-Concelman or British Navel Connector
BRI	basic rate interface
BTX	balanced technology extended
CCD	charged coupled device
CD	compact disc
CD-ROM	compact disc-read-only memory
CD-RW	compact disc-rewritable
CDFS	compact disc file system
CMOS	complementary metal-oxide semiconductor
CNR	communication network riser
COM1	communication port 1
CPU	central processing unit
CRIMM	continuity-rambus inline memory module
CRT	cathode-ray tube
DAC	discretionary access control
DB-25	serial communications D-shell connector, 25 pins
DB-9	9 pin D shell connector
DC	direct current
DDOS	distributed denial of service
DDR	double data-rate
DDR RAM	double data-rate random access memory
DDR SDRAM	double data-rate synchronous dynamic random access memory
DFS	distributed file system
DHCP	dynamic host configuration protocol
DIMM	dual inline memory module
DIN	Deutsche Industrie Norm
DIP	dual inline package
DLT	digital linear tape
DLP	digital light processing
DMA	direct memory access
DNS	domain name service or domain name server
DOS	disk operating system or denial of service
DPMS	display power management signaling
DRAM	dynamic random access memory
DSL	digital subscriber line
DVD	digital video disc or digital versatile disc
DVD-RAM	digital video disc-random access memory
DVD-ROM	digital video disc-read only memory
DVD-R	digital video disc-recordable
DVD-RW	digital video disc-rewritable
DVI	digital visual interface
ECC	error correction code
ECP	extended capabilities port
EEPROM	electrically erasable programmable read-only memory
EFS	encrypting file system
EIDE	enhanced integrated drive electronics
EISA	extended industry standard architecture
EMI	electromagnetic interference
EMP	electromagnetic pulse
EPROM	erasable programmable read-only memory
EPP	enhanced parallel port
ERD	emergency repair disk
ESD	electrostatic discharge
ESDI	enhanced small device interface
EVGA	extended video graphics adapter/array
EVDO	evolution data optimized or evolution data only
FAT	file allocation table
FAT12	12-bit file allocation table
FAT16	16-bit file allocation table
FAT32	32-bit file allocation table
FDD	floppy disk drive
FERPA	Family Educational Rights and Privacy Act
Fn	Function (referring to the function key on a laptop)
FPM	fast page-mode
FRU	field replaceable unit
FT	P file transfer protocol
FQDN	fully qualified domain name
GB	gigabyte
GDI	graphics device interface
GHz	gigahertz
GUI	graphical user interface
GPRS	general packet radio system
GSM	global system for mobile communications
HAL	hardware abstraction layer
HCL	hardware compatibility list
HDD	hard disk drive
HDMi	high definition media interface
HPFS	high performance file system
HTML	hypertext markup language
HTTP	hypertext transfer protocol
HTTPS	hypertext transfer protocol over secure sockets layer
I/O	input/output
ICMP	internet control message protocol
ICS	internet connection sharing
ICR	intelligent character recognition
IDE	integrated drive electronics
IEEE	Institute of Electrical and Electronics Engineers
IIS	Internet Information Services
IMAP	internet mail access protocol
IP	internet protocol
IPCONFIG	internet protocol configuration
IPP	internet printing protocol
IPSEC	internet protocol security
IPX	internetwork packet exchange
IPX/SPX	internetwork packet exchange/sequenced packet exchange
IR	infrared
IrDA	Infrared Data Association
IRQ	interrupt request
ISA	industry standard architecture
ISDN	integrated services digital network
ISO	Industry Standards Organization
ISP	internet service provider
KB	kilobyte
LAN	local area network
LBA	logical block addressing
LC	Lucent connector
LCD	liquid crystal display
LDAP	lightweight directory access protocol
LED	light emitting diode
LIP	or LiPoly lithium-ion polymer
Li-on	lithium-ion
LPD/LPR	line printer daemon / line printer remote
LPT	line printer terminal
LPT1	line printer terminal 1
LPX	low profile extended
LVD	low voltage differential
MAC	media access control
MAN	metropolitan area network
MAPI	messaging application programming interface
Mb	megabit
MB	megabyte
MBR	master boot record
MBSA	Microsoft Baseline Security Analyzer
MCR	multivariant curve resolution
MFD	multi-function device
MFP	multi-function product
MHz	megahertz
MicroDIMM	micro dual inline memory module
MIDI	musical instrument digital interface
MIME	multipurpose internet mail extension
MLI	multiple link interface
MMC	Microsoft management console
MMX	multimedia extensions
MP3	Moving Picture Experts Group Layer 3 Audio
MPEG	Moving Picture Experts Group
MSCONFIG	Microsoft configuration
MSDS	material safety data sheet
MUI	multilingual user interface
NAS	network-attached storage
NAT	network address translation
NetBIOS	networked basic input/output system
NetBEUI	networked basic input/output system extended user interface
NFS	network file system
NIC	network interface card
NiCd	nickel cadmium
NiMH	nickel metal hydride
NLI	not logged in or natural language interface
NLX	new low-profile extended
NNTP	network news transfer protocol
NTFS	new technology file system
NTLDR	new technology loader
NWLINK	Netware Link
OCR	optical character recognition
OEM	original equipment manufacturer
OMR	optical mark recognition
OS	operating system
OSR	original equipment manufacturer service release
PAN	personal area network
PATA	parallel advanced technology attachment
PC	personal computer
PCI	peripheral component interconnect
PCIe	peripheral component interconnect express
PCIX	peripheral component interconnect extended
PCL	printer control language
PCMCIA	Personal Computer Memory Card International Association
PDA	personal digital assistant
PGA	pin grid array
PGA2	pin grid array 2
PIN	personal identification number
PKI	public key infrastructure
PnP	plug and play
POP	post office protocol
POP3	post office protocol 3
POST	power-on self test
POTS	plain old telephone service
PPP	point-to-point protocol
PPTP	point-to-point tunneling protocol
PRI	primary rate interface
PROM	programmable read-only memory
PS/2	Personal System/2 connector
PSTN	public switched telephone network
PVC	permanent virtual circuit
PXE	preboot execution environment
QoS	quality of service
RAID	redundant array of independent (or inexpensive) discs
RAM	random access memory
RAS	remote access service
RBAC	role-based access control or rule-based access control
RDRAM	RAMBUS dynamic random access memory
RF	radio frequency
RFI	radio frequency interference
RGB	red green blue
RIMM	RAMBUS inline memory module
RIP	routing information protocol
RIS	remote installation service
RISC	reduced instruction set computer
RJ	registered jack
RJ-11	registered jack function 11
RJ-45	registered jack function 45
RMA	returned materials authorization
ROM	read only memory
RS-232 or RS-232C	recommended standard 232
RTC	real-time clock
SAN	storage area network
SATA	serial advanced technology attachment
SC	subscription channel
SCSI	small computer system interface
SCSI ID	small computer system interface identifier
SD	card secure digital card
SDRAM	synchronous dynamic random access memory
SEC	single edge connector
SFC	system file checker
SGRAM	synchronous graphics random access memory
SIMM	single inline memory module
SLI	scalable link interface or system level integration or scanline interleave mode
SMB	server message block or small to midsize business
SMTP	simple mail transport protocol
SNMP	simple network management protocol
SoDIMM	small outline dual inline memory module
SOHO	small office/home office
SP	service pack
SP1	service pack 1
SP2	service pack 2
SPDIF	Sony-Philips digital interface format
SPGA	staggered pin grid array
SPX	sequenced package exchange
SRAM	static random access memory
SSH	secure shell
SSID	service set identifier
SSL	secure sockets layer
ST	straight tip
STP	shielded twisted pair
SVGA	super video graphics array
SXGA	super extended graphics array
TB	terabyte
TCP	transmission control protocol
TCP/IP	transmission control protocol/internet protocol
TDR	time domain reflectometer
TFTP	trivial file transfer protocol
UART	universal asynchronous receiver transmitter
UDF	user defined functions or universal disk format or universal data format
UDMA	ultra direct memory access
UDP	user datagram protocol
UL	Underwriter’s Laboratory
UNC	universal naming convention
UPS	uninterruptible power supply
URL	uniform resource locator
USB	universal serial bus
USMT	user state migration tool
UTP	unshielded twisted pair
UXGA	ultra extended graphics array
VESA	Video Electronics Standards Association
VFAT	virtual file allocation table
VGA	video graphics array
VoIP	voice over internet protocol
VPN	virtual private network
VRAM	video random access memory
WAN	wide area network
WAP	wireless application protocol
WEP	wired equivalent privacy
WIFI	wireless fidelity
WINS	windows internet name service
WLAN	wireless local area network
WPA	wireless protected access
WUXGA	wide ultra extended graphics array
XGA	extended graphics array
ZIF	zero-insertion-force
ZIP	zigzag inline package