Date: Tue, 3 Dec 2013 07:07:18 +0000 (UTC) From: "Thomas Mueller" <mueller6724@bellsouth.net> To: freebsd-questions@FreeBSD.org Subject: Re: gmirror, gpart and MBR vs GPT in the Handbook Message-ID: <251695.62121.bm@smtp119.sbc.mail.bf1.yahoo.com> References: <201311301303210813.05DE187E@smtp.24cl.home> <alpine.BSF.2.00.1311301352140.99113@wonkity.com> <201312011121580096.005D00FB@smtp.24cl.home> <alpine.BSF.2.00.1312011016490.5791@wonkity.com> <201312021213320528.00673D5F@smtp.24cl.home> <alpine.BSF.2.00.1312021411420.15921@wonkity.com>
next in thread | previous in thread | raw e-mail | index | archive | help
from Warren Block: > As far as I recall, MBR expects 512-byte blocks and uses 32-bit > values. The total number works out to 2TB (2^32*512). > Just recently, someone in the forums had an external drive, MBR > format, but 4K blocks. There were problems, although I don't know if > FreeBSD was at fault. > I have not tried MBR on a drive larger than 2TB. I suspect it would > be safe to use the first 2TB and ignore the rest, but that really > ought to be verified. There are ways (kludges) to get MBR on a drive > 2TB. Western Digital My Book 3TB USB 3.0 hard drive was formatted with a single huge NTFS partition with some software. In order to copy the stuff, which I've never used, I had to use the System Rescue CD. Subsequently I migrated to GPT, deleted the huge partition, and made my own GPT partitions. OpenBSD has a kludge with fdisk + disklabel whereby everything over 2TB goes into one (or more) disklabel partitions, but boot partition must be entirely within first 2TB. I never tried that and don't plan to. fdisk can't see the slice that goes past 2TB, but OpenBSD can, according to what I read on OpenBSD online documentation. I never tried that. OpenBSD can't access my hard drive at all for lack of support for USB 3.0 and GPT. DragonFlyBSD latest release, 3.6.0, downloaded, bzip2 -d and dd'ed to USB sticks recognizes my hard drive partitions but can't mount any. So all I can do with OpenBSD is download the Live USB from liveusb-openbsd.sourceforge.net, run 7z e on the download, which is 7-zipped. 7-zip (archivers/p7zip) is in FreeBSD ports, which is how I built it. NetBSD supports GPT, but the dk wedges are not as elegant as what FreeBSD and Linux do. NetBSD seems to be just starting with USB 3.0 support in -current. NetBSD and OpenBSD still use preassigned device nodes with MAKEDEV such as Linux and FreeBSD had some years back. This is actually sort of a combined response to two threads, other one being Re: kernel "mismatch" on r256420. Tom
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?251695.62121.bm>