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EXT2 / EXT3 / ReiserFS

By DigitAlex
Jun 10, 2004
  1. what are the big differences please ?

    I mean on practical side, i don't really mind the theory behind it, i just wanna know what it can change actually ....

    i seem to know that the 2 last ones are journalized, but that's all.

    and another thing, is it possible to switch from one to another or do i have to install the distro again from scratch ?

    thanks
     
  2. Nodsu

    Nodsu TS Rookie Posts: 9,431

    Ext2 doesn't have journalling so it breaks easily.
    Ext3 is basically ext2 plus a journal. Maybe a tad slower because of it.
    ReiserFS is Something Completely Different. It performs better in extreme conditions (heavy load, thousands of files in a dir etc.)

    You can switch between ext2 and ext3. I don't know if there is anything that can convert between ReiserFS.

    If you want performance and to look cool, go for Reiser. If you are dual booting, you will not be able to access files on a Reiser partition from Windows.

    If you want to play safe and have access to your Linux files from Windows, go for Ext. If you want to write to your Linux partition from Windows, you need Ext2.

    From Linux point of view, you have a choice between Ext3 and reiser.
    From Windows point of view you have the writable and easily breaking Ext2 or the read-only Ext3.
     
  3. DigitAlex

    DigitAlex TechSpot Paladin Topic Starter Posts: 583

    It's a pure debian box
    very old PC
    not lots of files
    windows doenst have to access the linux box, but the contrary, so i don't think it will change anything
    so from what i have read, ext3 would be a better choice since i already have installed on ext2 and can switch
    by the way, how can i do that ?
     
  4. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    I usually use Ext2 on dual boot machines, and Ext3 for machines that only have Linux.

    Ext3 does not work with PowerQuest drive image as well, which is annoying because I make extensive use of this product.
     
  5. DigitAlex

    DigitAlex TechSpot Paladin Topic Starter Posts: 583

    what about ghost ? issues with ext3 ?
     
  6. Nodsu

    Nodsu TS Rookie Posts: 9,431

    "tune2fs -j /dev/hdxy" Will add a journal to an existing ext2 filesystem.

    You have to make sure your kernel supports ext3 before doing that tho. If the kernel is anything newer than 3 years then it probably supports it.
     
  7. DigitAlex

    DigitAlex TechSpot Paladin Topic Starter Posts: 583

    2.4.18 so i guess it's ok

    what is the real advantages of journalising ?
     
  8. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    You will be fine, Alex, so long as Ext3 is actually compiled into your kernel. That version of the kernel code supports it as far as I know, if you are using a distribution kernel then it probably came with it enabled.

    having a journal will make it much less likely that your file system will become corrupted if your system crashes.

    tune2fs is a very hard command - you should all read the man page for it.
     
  9. DigitAlex

    DigitAlex TechSpot Paladin Topic Starter Posts: 583

    it's a custom kernel so I think i'll have to recompile it again to enable ext3
     
  10. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    well, if you still have the config file you used you could cat and grep that and see if you used ext3....

    cat .config | grep -i ext3

    if you recompile, see if ext2 is compiled into the kernel, or is a module. i think its in the kernel.

    you could then convert your ext2 to ext3 using the tune2fs command that Nodsu has noted.
     
  11. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,916   +9

    Linux filesystems benchmarks, includes ext2, ext3 and ReiserFS

    Namesys, the creator of ReiserFS

    LinuxPlanet looks at ReiserFS
     
     
  12. DigitAlex

    DigitAlex TechSpot Paladin Topic Starter Posts: 583

    Thanks Mic.

    Phant, I didn't use ext3 support when compiling.
     
  13. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    [root]# more mykernel.conf | grep -i ext3
    CONFIG_EXT3_FS=m
    CONFIG_EXT3_FS_XATTR=y
    CONFIG_EXT3_FS_POSIX_ACL=y
    CONFIG_EXT3_FS_SECURITY=y


    I guess its OK to have Ext3 as a module, then....

    But see how Ext2 is always compiled directly into the kernel...

    CONFIG_EXT2_FS=y
    CONFIG_EXT2_FS_XATTR=y
    CONFIG_EXT2_FS_POSIX_ACL=y
    CONFIG_EXT2_FS_SECURITY=y


    These were the defaults from Red Hat supplied kernel config files.


    But there's no harm whatsoever in compiling Ext3 in as well so I guess you should if it lets you.
     
  14. Goalie

    Goalie TS Rookie Posts: 703

    iirc, Ghost doesn't have any trouble with ext3. Dunno about reiserfs, I vaguely recall having ghosted one of those in the past, but could be wrong.
     
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