On Fri, Sep 4, 2009 at 8:59 AM, Rishi Agrawal<rishi.b.agrawal@xxxxxxxxx> wrote: > Hello All, > > I found this paragraph while understanding file systems. > > " > I assume that you are setting this up with ext3 and hence my answer ties to > this. If your filesystem is different, you should say so. > > Note: *In ext3, an 8K block size on the fs is only possible if you use > Itanium and other 8K architectures. If your architecture is x86, x86_64, it > is not possible to have a block size greater than 4k*. If you try to make an > ext3 fs you will fail with an error message similar to this: > > mkfs.ext3: 8192-byte blocks too big for system (max 4096) > > So,if your server architecture can take it, you can > i)use parted post installation to make the partition and then type the > following example (if your partition is called for instance /dev/sda2): > > mkfs -t ext3 -b 8192 /dev/sda2 > " > link : http://osdir.com/ml/redhat-list/2009-06/msg00131.html > > > I could not figure out the dependency between the file system block size and > the architecture. > > Can somebody guide me in this ? Rishi, I don't know the answers, but I'm pretty sure your question can be broken into two. 1) Why does the Linux MM system restrict 32-bit kernels to 4K pages? (Probably has to do with the MMU, but I don't know). 2) Why do most linux filesystem use disk blocks <= a memory page? (I suspect this is tied to the design of the block layer elevators, etc.) fyi: I'm not sure all filesystems have that restriction. So you may find that 8k blocks are supported with 32-bit kernels in some filesystems. Greg -- Greg Freemyer Head of EDD Tape Extraction and Processing team Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer Preservation and Forensic processing of Exchange Repositories White Paper - <http://www.norcrossgroup.com/forms/whitepapers/tng_whitepaper_fpe.html> The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
