Messages in this thread | | | From | (H. Peter Anvin) | Subject | Re: atomicity | Date | 7 Dec 1998 19:55:43 GMT |
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Followup to: <m3soeszi1e.fsf@trantor.cosmic.com> By author: Mirian Crzig Lennox <mirian@xensei.com> In newsgroup: linux.dev.kernel > > alan@lxorguk.ukuu.org.uk (Alan Cox) writes: > > > > ext2fs tries to grab linear chunks of disk and divides the disk into cylinder > > groups to also help to maintain locality. The BSD ffs papers [McKusik et al] > > describe this sort of stuff well. > > I am astonished to hear that ext2fs uses cyl groups. > > I was of the impression that these were an artefact of ffs, and really > not useful anymore. With modern disks, chances are excellent that the > specific 3D geometry the file system sees is an utter fiction, and > that cylinder locality is thus more-or-less a meaningless concept. >
Actually, ext2fs uses *block groups*. It aligns them on a number of blocks that's a power of 2 (usually 2^13 blocks); not on a "cylinder" boundary.
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