On Jul 19, 2011, at 2:10 PM, Peter Jeremy wrote: > On 2011-Jul-19 10:54:38 -0700, Chuck Swiger <cswi...@mac.com> wrote: >> Unix operating >> systems like SunOS 3 and NEXTSTEP would happily run with a DEV_BSIZE >> of 1024 or larger-- they'd boot fine off of optical media using >> 2048-byte sectors, > > Actually, Sun used customised CD-ROM drives that faked 512-byte > sectors to work around their lack of support for anything else.
Hmm-- my brain could be fuzzy about things twenty-plus years ago. But I remember booting a Sun3_35 or _60 from a non-Sun or Sun OEM'ed SCSI CD-ROM drive, probably a Plextor? >> some of the early 1990's era SCSI hard drives supported low-level >> reformatting to a different sector size like 1024 or 2048 bytes. > > Did anyone actually do this? I wanted to but was warned against > it by the local OS rep (this was a Motorola SVR2). Worked fine with 250MB Seagate ST1280 drives, and also a a 1GB Micropolis 2112. It made a decent gain to available disk capacity (about 10-15%), and a smaller improvement to performance (about 5% IIRC). It wouldn't work with drives using a dedicated embedded servo for sector positioning (ie, Quantum and DEC), but other vendors like Seagate used a normal platter surface for servo positioning, and you could reformat it with a different sector size. Regards, -- -Chuck _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
