In message <[EMAIL PROTECTED]>, "Bruce M. Simpson" writes: >Poul-Henning Kamp wrote: >> I have the attached patch in sos@ mailbox for approval, that adds >> BIO_DELETE support for the ata driver. >> >> I also want to implement a -E option to fsck(8) to erase all >> unallocated blocks. >> >> And finally the big item: msdosfs and ufs support to issue BIO_DELETE >> when files are deleted. UFS is nasty because of soft-updates. >> > >Aha, I understand now. CFA and SATA vendors have gone off in two >separate directions: > * PATA and SATA drives, for a few years now, have tended to rewrite one >cylinder at a time, which implies erasing the data on that cylinder.
Everybody denies this in the stongest possibly way whenever I ask them, so far I have not seen this claim substantiated by any fact or person who would be in a position to know. > * NAND Flash devices should not have their sectors erased unless >absolutely necessary, to implement wear levelling. Wrong, almost exactly the opposite in fact: Flash devices using wear-levelling should have data erased as soon as possible to give the wear-levelling the maximum amount of information and available space to work with. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ cvs-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/cvs-all To unsubscribe, send any mail to "[EMAIL PROTECTED]"
