Date: Sat, 1 May 1999 07:14:48 +1000 From: Bruce Evans <bde@zeta.org.au> To: dfr@nlsystems.com, klh@us.oracle.com Cc: freebsd-fs@FreeBSD.ORG Subject: Re: When is a FFS not a FFS? Message-ID: <199904302114.HAA19815@godzilla.zeta.org.au>
next in thread | raw e-mail | index | archive | help
>FreeBSD/alpha will mount UFS filesystems from NetBSD/alpha and OSF1 with >no problems at all. Your problem is that FreeBSD/i386 puts the disklabel >at a different place on the disk from the alpha OSs. On the alpha, the >disklabel is stored at offset 64 in block zero but on FreeBSD/i386, it is >stored at offset zero in block one of the FreeBSD fdisk slice (which can >be anywhere). This doesn't explain why `disklabel -r da5' seemed to work, or how NetBSD/i386 handled labels at a nonstandard offset. I think alpha disks can only be handled by putting suitable metadata in sectors 0 and 1. Metadata suitable for NetBSD is not necessarily suitable for FreeBSD. `disklabel -r' is apparently finding slightly unsuitable metadata. For FreeBSD, sector 0 should not end with bytes { 0x55, 0xAA }, or else it will be considered to contain a DOS partition table and you would have to fudge that right too. Sector 1 must contain a valid label. A valid label for NetBSD needs more fudging than a valid label for FreeBSD, since the "raw" partition is 3 ('d') for NetBSD-i386 and 2 ('c') for NetBSD-alpha and FreeBSD-any. However, I think NetBSD-i386 labels look like FreeBSD-2.0 labels, and FreeBSD fixes up the latter. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199904302114.HAA19815>