-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Monday, 2010-02-15 at 19:25 -0500, Anton Aylward wrote: ...
Somehow I don't think that kind of defrag does what you think it does.
So, back to the idea of things like cylinder groups and locality; if we can't guarantee contiguous blocks layout then at least lets keep head motion down.
The strategy would then be to store a group of read requests, learn where the files are located, then plan an strategy to read all that with a good buffer, optimizing the head movements. Ie, do not read the first file directly, but wait for several requests needing to be served before planning the best strategy. Defragging is probably useless. At best, the kernel could store in a database what requests are usually grouped together and then optimize file locations. Actually, if a group of files is going to be read, it is probably best to interleave them, ie, fragmentating them on purpose. I think that what we need is better, faster hardware. Disks with independent heads, capable of reading several sectors at the same time, and having internal buffers in the hundreds of megabytes range. Unfragmenting is not going to be that useful on a multitasking os. - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEARECAAYFAkt57CgACgkQtTMYHG2NR9XBxQCfbJiXJKA3nrE5hbCAHnKaSbRi RTwAn1EtFYC8ZG+YQlq4dDI186etxR28 =gN4R -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org