On Fri, 2005-12-30 at 10:10 -0600, Mike McCarty wrote:
Again, the point was that some claim that ext3 does not and will not fragment files which are not dynamic. I claimed that fragmentation can occur simply due to install of software, which some claimed will not and does not occur with ext3. I think that I have demonstrated my point. In fact, I was quite shocked that it was as bad as that, frankly.
Hi Mike,
OK, fragmentation can and sometimes does occur. You've explained why and how.
So the next logical question is: what difference, if any, does it make? Can you or anyone else come up with a way to measure the effect or some aspect of it? Perhaps a benchmark that shows how application startup times suffer?
I'm not a filesystems guru, but even so its not at all clear to me that fragmentation must necessarily cause a big or repeated performance hit. Given Linux's VM, it seems plausible that an initial file load might suffer (maybe a lot or maybe a tiny bit?) and that subsequent file accesses will be from pages already cached in RAM.
We should all keep open minds and, if possible, generate some actual benchmark data!
Ed