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This is a discussion on File systems for SD cards - Embedded ; I will be making extensive use of SD cards on a project... I am wondering if there is a better file system for 256 MB - 2GB SD cards than VFAT.... Thanks, --Yan -- o__ ,>/'_ o__ (_)\(_) ,>/'_ o__ ...

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  1. File systems for SD cards

    I will be making extensive use of SD cards on a project...

    I am wondering if there is a better file system for 256 MB - 2GB SD cards
    than VFAT....

    Thanks,

    --Yan

    --
    o__
    ,>/'_ o__
    (_)\(_) ,>/'_ o__
    Yan Seiner, PE (_)\(_) ,>/'_ o__
    Certified Personal Trainer (_)\(_) ,>/'_ o__
    Licensed Professional Engineer (_)\(_) ,>/'_
    Who says engineers have to be pencil necked geeks? (_)\(_)


  2. Re: File systems for SD cards

    > I am wondering if there is a better file system for 256 MB - 2GB SD cards
    > than VFAT....


    I don't think that there is any limitation what file system to use on an
    SD-Card. So why not do NTFS .

    -Michael

  3. Re: File systems for SD cards

    "Michael Schnell" wrote in message
    news:ebq2sd$gg9$1@murphy.mediascape.de...
    > > I am wondering if there is a better file system for 256 MB - 2GB SD

    cards
    > > than VFAT....

    >
    > I don't think that there is any limitation what file system to use on an
    > SD-Card. So why not do NTFS .


    Thats not the way I see it. SD Cards require the SD File System otherwise
    they aren't SD cards anymore.

    Peter



  4. Re: File systems for SD cards


    Captain Dondo wrote:
    > I will be making extensive use of SD cards on a project...
    >
    > I am wondering if there is a better file system for 256 MB - 2GB SD cards
    > than VFAT....
    >


    With Linux you can use just about any file system you want. Choose one
    that's native to Linux -- ext3, reiser, etc..


  5. Re: File systems for SD cards

    > Thats not the way I see it. SD Cards require the SD File System otherwise
    > they aren't SD cards anymore.


    Right ! No chance to exchange them with other systems.

    -Michael

  6. Re: File systems for SD cards


    Captain Dondo wrote:
    > I will be making extensive use of SD cards on a project...
    >
    > I am wondering if there is a better file system for 256 MB - 2GB SD cards
    > than VFAT....


    So long as you don't care about non-linux portability, then any
    linux-supported fs should do. However, I'd stay away from journalling
    filesystems (flash memory has a large but limited number of write
    cycles, and journals add to the # of writes), and look at low-overhead
    filesystems. My personal choice would likely be the Minix fs (for
    general portability) or one of the memory filesystems (ramfs?)
    specifically designed for these sorts of devices.

    HTH
    --
    Lew Pitcher


  7. Re: File systems for SD cards

    Lew Pitcher wrote:
    > Captain Dondo wrote:
    >> I will be making extensive use of SD cards on a project...
    >>
    >> I am wondering if there is a better file system for 256 MB - 2GB SD cards
    >> than VFAT....

    >
    > So long as you don't care about non-linux portability, then any
    > linux-supported fs should do. However, I'd stay away from journalling
    > filesystems (flash memory has a large but limited number of write
    > cycles, and journals add to the # of writes), and look at low-overhead
    > filesystems. My personal choice would likely be the Minix fs (for
    > general portability) or one of the memory filesystems (ramfs?)
    > specifically designed for these sorts of devices.


    Acutally non-portable is good (security through obscurity is a good
    thing, no? :-) )

    Seriously, I am trying to fix some performance issues - very slow access
    with multiple processes accessing the SD card - and I am trying to
    experiment with different file systems for SD to see if they are more
    suitable for this than vfat. The SD card seems to bog down seriously
    with different processes accessing it at once....

    I'm going to try ext2 but I will give minix fs a try. I tried to use
    jffs but it doesn't work with SD cards all as they emulate scsi devices,
    and the kernel doesn't see them as mtd.

    Something like jffs for scsi would be good to try...

    --Yan

  8. Re: File systems for SD cards

    > Seriously, I am trying to fix some performance issues - very slow
    access
    > with multiple processes accessing the SD card - and I am trying to
    > experiment with different file systems for SD to see if they are more
    > suitable for this than vfat. The SD card seems to bog down seriously
    > with different processes accessing it at once....
    >
    > I'm going to try ext2 but I will give minix fs a try. I tried to use
    > jffs but it doesn't work with SD cards all as they emulate scsi devices,
    > and the kernel doesn't see them as mtd.


    Just FYI,

    I have a Sharp Zaurus (CL-3000 Japanese-only model from importer). It's a
    linux-based PDA/micro-laptop. I found a HUGE improvement in speed of
    access when I reformatted my external SD cards to EXT2. I don't do a lot
    of writing to them, primarily readback of datafiles and .oggs for music.
    As a rough estimate, I'd say write-speed is 2-3X faster and readback is
    easily 5-10x faster, especially with multiple processes accessing files on
    the card.

    YMMV,
    -S

  9. Re: File systems for SD cards

    shawn wrote:
    >> Seriously, I am trying to fix some performance issues - very slow

    > access
    >> with multiple processes accessing the SD card - and I am trying to
    >> experiment with different file systems for SD to see if they are more
    >> suitable for this than vfat. The SD card seems to bog down seriously
    >> with different processes accessing it at once....
    >>
    >> I'm going to try ext2 but I will give minix fs a try. I tried to use
    >> jffs but it doesn't work with SD cards all as they emulate scsi devices,
    >> and the kernel doesn't see them as mtd.

    >
    > Just FYI,
    >
    > I have a Sharp Zaurus (CL-3000 Japanese-only model from importer). It's a
    > linux-based PDA/micro-laptop.


    :-) I have a 3100, bought in Japan last X-mas. Ain't it great? I
    wish they brought them here.

    > I found a HUGE improvement in speed of
    > access when I reformatted my external SD cards to EXT2. I don't do a lot
    > of writing to them, primarily readback of datafiles and .oggs for music.
    > As a rough estimate, I'd say write-speed is 2-3X faster and readback is
    > easily 5-10x faster, especially with multiple processes accessing files on
    > the card.


    OK, thanks. I'll give it a try. Any special mounting options?

    I figure async,noatime,rw should be enough for me...

    --Yan
    >
    > YMMV,
    > -S


  10. Re: File systems for SD cards

    Captain Dondo writes:

    >I will be making extensive use of SD cards on a project...


    If it is used in a camera, then you had better use the same file system the
    camera uses (usually vfat). If not, put whatever you want on it, but if you
    want both linux and windows to use it, better stick with vfat.


    >I am wondering if there is a better file system for 256 MB - 2GB SD cards
    >than VFAT....




  11. Re: File systems for SD cards


    > Acutally non-portable is good (security through obscurity is a good
    > thing, no? :-) )


    Ask Uncle Bill Gates......

    Dave

  12. Re: File systems for SD cards

    On Mon, 14 Aug 2006 08:35:27 -0700, Lew Pitcher wrote:

    > filesystems. My personal choice would likely be the Minix fs (for
    > general portability) or one of the memory filesystems (ramfs?)
    > specifically designed for these sorts of devices.


    I think minix fs would cause as many problems as it would seem to solve,
    such as filname limitations and (IIRC) fragmentation vulnerability. I
    don't know about the utility of ramfs for this, but I've used ext2 on an
    sd card for years.

    --

    David L. Johnson

    __o | Arguing with an engineer is like mud wrestling with a pig... You
    _`\(,_ | soon find out the pig likes it!
    (_)/ (_) |

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