How does filesystem fragmentation (non-contiguous data blocks) differ among mediae (RAM disk, HDD, floppy, what-have-you)?

For example, if I read and write to my a RAM disk the exact same bytes as I do to my hard disk across a period of time, will I see a different amount of filesystem fragmentation?

  • Assuming you are referring to reserving memory to be used as a storage medium then yes the fragmentation would still occur but it is a non-issue just like SSDs – MonkeyZeus Oct 24 '13 at 17:35
  • Please define which type of "fragmentation" you're asking about. Are you referring to non-contiguous data block? Are you referring to wasted spaced by partially used blocks at the end of files? en.wikipedia.org/wiki/Fragmentation_%28computing%29 – sawdust Oct 25 '13 at 1:11
  • @sawdust edited my question to reflect this. – Richard Oct 25 '13 at 1:19

The fragmentation doesn't depend on the medium per se. If you use a 1GB RAM disk with the same filesystem as a 1GB hard disk, the fragmentaten will be the same. But different filesystems have different fragmentation characteristics. FAT filesystem for example is much worse than modern filesystems. And a RAM disk probably uses a special filesystem. OTOH a RAM disk or flash memory don't suffer as much from fragmentation as a spinning disk, as they have mostly random access and it doesn't matter much if they access blocks from different areas of the disk or consecutive blocks.

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  • Technically fragmentation is a problem ( it exists ) on flash media ( flash drives, ssd, ect ) but its existance does not change the access times of the drive. The reason fragmentation is a problem on magnetic drive is how the mechanical operation of the drives work ( it spins (optical disk), or there is a platter and head (hdd) ) which fragmentation has a huge impact on. I put odd in that statement because if optical disk fragmentation did exist it would be a problem because of how the laser reads different tracks. – Ramhound Oct 24 '13 at 17:48
  • A better answer would incorporate what kind of "fragmentation" it is explaining. – sawdust Oct 25 '13 at 1:13
  • @Ramhound -- "it spins (optical disk), or there is a platter and head (hdd)" -- HDDs also "spin" and optical disks have a surface and use a "head" (that has seek and rotational latency just like a HDD). The distinction between optical drive versus HDD is optical laser versus magnetic, and not spin or platter/head related. – sawdust Oct 25 '13 at 1:17
  • @sawdust my statement was very generic on purpose. I understand the platter disks also spin the difference an optical disc does not have fragmentation – Ramhound Oct 25 '13 at 2:52

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