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Saturday, May 14, 2011

Diff ext2 ext3 ext4

xxxxxxxxxxxxxxxxxxxxx Diff ext2 ext3 ext4 xxxxxxxxxxxxxxxxxxxxxxxxx
Extended n file system

ext2 :
- Introduced with kernel 1.0 in 1993
- Flexible can handle upto 4TB
- super block feature increase file system performance
- ext2 reserve 5% of disk space for root
- ext2 is popular on USB and other solid-state devices.
  This is because it does not have a journaling function.
  so it generally makes fewer reads and writes to the drive,
  effectively extending the life of the device .
-  NO journalalizm

ext3 :
- Provide all the feature of ext 2 + journaling and backward compatibility .
- can upgrade ext2 to ext3 without loss of data.
- journaling feature speed up the system to recover the state after power-failure
  or improper mount unmount etc.
- Example: In ext2 in an improper unmount or in-between power-off etc.. so in time
  of receiver it checks whole file system .
  But in ext3 it keeps record of uncommitted file transactions and checks applied
  on on them so system will come back up in faster and quicker .
-

ext4:
- Introduced with kernel 2.6.28
- Ext4 is a deeper improvement over Ext3
- support  larger filesystem, faster checking, nanosecond timestamps,
  and verification of the journal through checksums.
- It’s backward and forward compatible with versions 2 and 3, so we can
  mount a ext2 or ext3 filesystem as ext4 .
- The main benefits that ext4 has over ext3 are:
  - faster time-stamping
  - faster file system checking
  - journaling check-sums
  - extents (basically automatic space allocation to avoid fragmentation)

What is Journalism in linxu file syatem ?
A journaling file system is a file system that keeps track of the changes that will be made in
a journal (usually a circular log in a dedicated area of the file system) before committing them to
the main file system. In the event of a system crash or power failure, such file systems are quicker
to bring back online and less likely to become corrupted.
difference between ext2 ext3 ext4, extended file system linux, ext2, ext3,ext4, what is ext in linux, partition types in linux, file partition in linux, linxu partitions , ext2 ext3, ext4 linux, linuxva, shirish, shukla

2 comments:

  1. Ohh!!! I forget above...as now it's more than year had..used to work on this level ... thanks interviewers ... asking same again ...

    -> In sort the main diff is journalism (the infromatin feed in inode table..).that may have various improvement wrt .. your disk/partition i/o and perormance of your r/w .. am not sure if interviewer expecting this theoritical difference ..

    --Shirish Shukla

    ReplyDelete
  2. HI

    i want know ldap configuration in Linux and how its works please guide me .



    Regards
    Danish

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