Definition and Differences Ext2, Ext3, Ext4, Swap

Definition and Differences Ext2, Ext3, Ext4, Swap

What is the File System? File systemmerupakan a method of storing and organizing data / files on the computer.

There are a lot of file system, and now I want to discuss Extended File System in Linux. From the ext2, ext3, and ext4 is the latest. Immediately wrote us discuss

1. Second Extended (ext2)

Second Extended File system (Ext2) designed by Rémy Card, a file system that is extensible and powerful for use on the Linux operating system. Ext2 first developed and integrated into the Linux kernel, and now their use is also being developed on other operating systems. The goal is to create a powerful file system, which can implement semantic files from UNIX and services have advanced features.

Basic skills EXT2

• EXT2 file system is able to support several types of standard UNIX files, like regular files, directories, device special files, and symbolic links.

• EXT2 able to manage system files are created in large partition.

• EXT2 file system is able to generate file names are long. Maximum of 255 characters.

• EXT2 need some blocks for the super user (root).

2. Third Extended File System (EXT3)

• EXT3 filesystem is a journalled

• Journalled filesystem is designed to help protect data that is in it.

• With journalled filesystem, then we no longer need to check the consistency of the data, which will take a very long time for my disk.

• EXT3 is a filesystem that was developed for use on the Linux operating system.

• EXT3 is the result of improvements EXT2 EXT2 into better shape by adding a variety of advantages

Suppose a case as follows:

After the failure of resources (unclean shutdown) or damage to the system, EXT2 file system must go through the process of checking with e2fsck program. This process can be a waste of time so that the boot process to be very long, especially for a large disk that contains a lot of data. In this process, all the data can not be accessed. Provided by the journal EXT3 cause no longer need to be checked data after a system failure. EXT3 is only checked when there is hardware damage such as damage to the hard disk, but this is very rare. Time required after an EXT3 file system (unclean shutdown) does not depend on the size of the file system or the number of files, but depending on the size of the journal used to maintain consistency. Large default journal takes approximately one second to recover, depending on the speed of the hardware.

The advantages:

Availability

Does not support EXT3 file system checking process, even when the system is not cleaned experienced "shutdown", except in some very rare hardware error. Things like this happen because the data is written or saved to disk in such a way that the file system is always consistent. The time required to recover an ext3 file system after the system has not been cleaned off is independent of the size of the file system or the number of files; however depends on the size of the "journal" used to maintain consistency. Journal of the original size (the default) takes about 1 second to recover (depending on the speed of the hardware).

Data Integrity

• By using the ext3 file system we can get stronger guarantees about data integrity in the case where the system has not been cleaned off (shutdown).

• We can choose the type and level of protection received data.

• We can choose to keep the file system consistent, but still allow damage to data in the file system in the case turned off (shutdown) system that has not been cleaned; This could provide speed improvements in some circumstances.

• Alternatively we can choose to be sure that the data is consistent with part of the file system; This means we will never see "garbage data" in the new files are rewritten after a "crash".

• a safe choice that is keeping the consistency of the data as part of the file system is the default option

Comparison EXT2 EXT3 VS

• In general, the principles in the same EXT2 EXT3.

• Method of file access, data security, and disk space usage between the two file systems are almost the same.

• The fundamental difference between the two file systems are journaling file system concepts are used in EXT3.

• The concept of journaling is causing EXT2 and EXT3 have differences in terms of durability and data recovery from damage.

• The concept of cause EXT3 journaling is much faster than EXT2 in doing data recovery due to damage.

3. Fourth Extended File System (Ext4)

Ext4 is complete and stable release of kernel 2.6.28 started so if your distro which by default has a kernel version or above its tersebuat automated system you already support ext4 (with records already in the include into the kernel) but it must use the version of e2fsprogs version 1:41 .5 or more. If you are still using ext3 fs can convert to ext4 with some steps that are not too complicated.

Benefits can be gained by upgrading to ext4 than ext3 filesystem is having 48-bit block addressing, which means he will have 1EB = 1,048,576 TB filesystem with a maximum size of 16 TB maximum file size for her, Fast fsck, Journal checksumming, Defragmentation support.

4. Swap

File System is not used as a data repository, but as virtual memory, that is, as the performance of the memory helper. Virtual memory is also used on windows as the page file, but if the swap is put on a different partition with the system and given a place of their own, he was on the page file on the same partition with the system or data.