Messages in this thread | | | Date | Sat, 4 Nov 2006 22:01:11 +0100 | From | Jan-Benedict Glaw <> | Subject | Re: New filesystem for Linux |
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On Sat, 2006-11-04 14:59:53 -0500, Albert Cahalan <acahalan@gmail.com> wrote: > Grzegorz Kulewski writes: > > On Thu, 2 Nov 2006, Mikulas Patocka wrote: > > > As my PhD thesis, I am designing and writing a filesystem, > > > and it's now in a state that it can be released. You can > > > download it from http://artax.karlin.mff.cuni.cz/~mikulas/spadfs/ > > > > "Disk that can atomically write one sector (512 bytes) so that > > the sector contains either old or new content in case of crash." > > New drives will soon use 4096-byte sectors. This is a better > match for the normal (non-VAX!) page size and reduces overhead.
Well... VAXen use physical PTEs for 512 byte pages, Linux uses 8 consecutive pages to simulate 4K pages.
On top of that, some of today's machines have configurable page sizes. Besides that, 512 byte sectors are quite a clever thing: Drives probably can write a number of consecutive sectors, so if you want to send a page, just send eight sectors.
> BTW, a person with disk recovery experience told me that drives > will sometimes reorder the sectors. Sector 42 becomes sector 7732, > sector 880880 becomes sector 12345, etc. The very best filesystems > can handle with without data loss. (for example, ZFS) Merely great > filesystems will at least recognize that the data has been trashed.
Uh? This should be transparent to the host computer, so logical sector numbers won't change.
MfG, JBG
-- Jan-Benedict Glaw jbglaw@lug-owl.de +49-172-7608481 Signature of: http://catb.org/~esr/faqs/smart-questions.html the second : [unhandled content-type:application/pgp-signature] | |