Date: Wed, 27 Feb 2002 21:42:48 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: "Kenneth D. Merry" <ken@kdm.org> Cc: Patrick Thomas <root@utility.clubscholarship.com>, <freebsd-scsi@FreeBSD.ORG> Subject: Re: IDE vs. SCSI partition and slice limits Message-ID: <20020227211531.F48298-100000@gamplex.bde.org> In-Reply-To: <20020226180128.A64373@panzer.kdm.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 26 Feb 2002, Kenneth D. Merry wrote: > [ You're sending mail as root. Generally that's a bad thing. ] > > On Tue, Feb 26, 2002 at 16:15:11 -0800, Patrick Thomas wrote: > > > > I have discovered, through trial and error, that when using IDE drives in > > FreeBSD I am limited to 4 slices per drive, and 8 partitions per slice. > > > > 1. Is what I just described correct, or was my trial and error flawed ? > > That is correct. For some values of I. The kernel (on i386's) supports 30 slices per drive. Some utilities only support 4, but it is easy to create another operating system's utilities to create more. In most cases that you need more, they will be for another operating system and will already have been created. Then you just use them. > > 2. Do these exact same limits exist for scsi drives, or are the numbers > > different (and if so, what are they) > > The slice limits are a general PC thing, and the partitions are a > limitation of the FreeBSD disklabel. No, the slice limits are arbitrary. PC's support billions of slices. The limit of 30 is related to the first power of 2 that is strictly larger than what was thought to be the corresponding arbitrary limit on the number of "slices" supported in MSDOS and Linux. This was tested using MSDOS fdisk to create logical drives C: through Z:. IIRC, MSDOS fdisk wouldn't create any drives after Z:, but someone said that MSDOS supports undocumented drives that can be named using ASCII characters after Z. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020227211531.F48298-100000>