Re: booting off GPT partitions
On Wed, 2010-01-27 at 20:23 -0600, Brooks Davis wrote: On Thu, Jan 28, 2010 at 12:27:54AM +0100, Dimitry Andric wrote: On 2010-01-27 22:27, John Baldwin wrote: GPT was defined along with EFI, so many folks assume that you have to use EFI to boot a GPT-labelled disk. However, FreeBSD has its own BIOS-based bootstrap that can handle GPT-labelled disks. I doubt the SuperMicro tech is familiar with that case. I thought I heard that some folks had added GPT support to grub as well. However, this won't boot disks larger than 2TiB, right? At least not without BIOS support... You won't be able to boot from a partition more than 2TiB in, but you should still be able to boot as long as you boot from the front part of the disk. John or Marcel can correct me, but I don't think that this is an issue. The bootstrap is located in the pmbr in sector 0 and the GPT headers and tables are in sectors 1 - 34. The bootstrap code knows how to read the GPT tables and can deal with 2 tb lba's. So, as long as you can successfully load the bootstrap code from sector 0, all *should* be good. robert. -- Brook -- Robert Noland rnol...@freebsd.org FreeBSD ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On 2010-01-28 13:06, Robert Noland wrote: John or Marcel can correct me, but I don't think that this is an issue. The bootstrap is located in the pmbr in sector 0 and the GPT headers and tables are in sectors 1 - 34. The bootstrap code knows how to read the GPT tables and can deal with 2 tb lba's. Ah yes, I see it now. It uses EDD packets with the BIOS int 13 interface, which apparently have a 64-bit LBA. This should support up to 8 ZiB with 512-byte sectors... OTOH, I have no idea how well most BIOSes actually implement this. Since many OSes simply don't support anything over 2^32 sectors, I would not be amazed to find much BIOSes out there that behave the same. Or am I too paranoid now? :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On Thursday 28 January 2010 7:26:24 am Dimitry Andric wrote: On 2010-01-28 13:06, Robert Noland wrote: John or Marcel can correct me, but I don't think that this is an issue. The bootstrap is located in the pmbr in sector 0 and the GPT headers and tables are in sectors 1 - 34. The bootstrap code knows how to read the GPT tables and can deal with 2 tb lba's. Ah yes, I see it now. It uses EDD packets with the BIOS int 13 interface, which apparently have a 64-bit LBA. This should support up to 8 ZiB with 512-byte sectors... OTOH, I have no idea how well most BIOSes actually implement this. Since many OSes simply don't support anything over 2^32 sectors, I would not be amazed to find much BIOSes out there that behave the same. Or am I too paranoid now? :) It should work fine. The GPT boot code was originally written specifically to supporting booting from RAID volumes 2TB. I've tested it on mfi(4) volumes that large (though I didn't verify the individual LBAs of all the various bits read in by the bootstrap and loader were). I know that other folks ran into bugs until the ZFS GPT boot code was all made 64-bit clean and that they have since booted 2TB ZFS volumes ok. -- John Baldwin ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On Wed, Jan 27, 2010 at 06:45:36PM +0200, Dan Naumov wrote: I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? For what it's worth, I've never encountered any production x86 system that I've worked on (Linux, FreeBSD, Solaris 10, or OpenSolaris) which has used GPT. I don't know who's giving you the impression that everyone and their dog is using GPT. Why is this feature a deal-breaker for you? Why are you giving it so much attention? -- | Jeremy Chadwick j...@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
GPT booting is I believe only natively supported using an EFI BIOS. However if you wish to use GPT booting with FreeBSD its not too hard, you just cant install using sysinstall. The Examples section of the gpart manpage is what i used to configure the disk for my home server, a zotac ion atom based board (dont have any production servers at work using it at the moment.) Then i just installed using the files on the usb image. From what I understand gpart installs the pmbr file as a basic bootstrap in the protective MBR present in the GPT partition scheme, this is bootable by a standard bios and is able to understand enough GPT to look for a freebsd boot partition, load the bootcode in that, which loads the kernel etc. So no they arent completely misguided, but its certainly possible to use a GPT scheme without an EFI BIOS. What I would like is an efi bootloader for i386 so I can get my powerbook to run FreeBSD again as it has got an efi bios and bootcamp wont boot freebsd for me at the moment :( Vince Dan Naumov wrote: Hey I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? - Sincerely, Dan Naumov ___ freebsd-sta...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to freebsd-stable-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
on 27/01/2010 18:45 Dan Naumov said the following: Hey I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? Perhaps both :-) It depends on what booting capabilities you need from your BIOS. With FreeBSD we currently typically don't use pure GPT and use Protective MBR and install real boot code into a special boot partition. Protective MBR looks like a normal MBR to BIOS, and boot code in Protective MBR is smart to find the boot partition and hand off boot process to code in it. This way you can almost have the best of both worlds, but with some limitations (like multibooting). I don't know what other OSes do or expect in this area. Obligatory wikipedia link: http://en.wikipedia.org/wiki/GUID_Partition_Table#Legacy_MBR_.28LBA_0.29 -- Andriy Gapon ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On Wed, Jan 27, 2010 at 06:45:36PM +0200, Dan Naumov wrote: Hey I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? The compatability MBR should be sufficent to let a non-GPT aware BIOS boot from GPT. Once you've loaded code from the boot partition, the BIOS doesn't need to know anything about the partitions. -- Brooks pgpCLNbdHGH7i.pgp Description: PGP signature
Re: booting off GPT partitions
On Wed, Jan 27, 2010 at 8:45 AM, Dan Naumov dan.nau...@gmail.com wrote: Hey I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? I'm booting servers with SuperMicro X8STi-F motherboards just fine using pmbr + GPT + ZFS. Matt ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On Wednesday 27 January 2010 11:45:36 am Dan Naumov wrote: Hey I was under the impression that everyone and their dog is using GPT partitioning in FreeBSD these days, including for boot drives and that I was just being unlucky with my current NAS motherboard (Intel D945GCLF2) having supposedly shaky support for GPT boot. But right now I am having an email exchange with Supermicro support (whom I contacted since I am pondering their X7SPA-H board for a new system), who are telling me that booting off GPT requires UEFI BIOS, which is supposedly a very new thing and that for example NONE of their current motherboards have support for this. Am I misunderstanding something or is the Supermicro support tech misguided? GPT was defined along with EFI, so many folks assume that you have to use EFI to boot a GPT-labelled disk. However, FreeBSD has its own BIOS-based bootstrap that can handle GPT-labelled disks. I doubt the SuperMicro tech is familiar with that case. I thought I heard that some folks had added GPT support to grub as well. -- John Baldwin ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On 2010-01-27 22:27, John Baldwin wrote: GPT was defined along with EFI, so many folks assume that you have to use EFI to boot a GPT-labelled disk. However, FreeBSD has its own BIOS-based bootstrap that can handle GPT-labelled disks. I doubt the SuperMicro tech is familiar with that case. I thought I heard that some folks had added GPT support to grub as well. However, this won't boot disks larger than 2TiB, right? At least not without BIOS support... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: booting off GPT partitions
On Thu, Jan 28, 2010 at 12:27:54AM +0100, Dimitry Andric wrote: On 2010-01-27 22:27, John Baldwin wrote: GPT was defined along with EFI, so many folks assume that you have to use EFI to boot a GPT-labelled disk. However, FreeBSD has its own BIOS-based bootstrap that can handle GPT-labelled disks. I doubt the SuperMicro tech is familiar with that case. I thought I heard that some folks had added GPT support to grub as well. However, this won't boot disks larger than 2TiB, right? At least not without BIOS support... You won't be able to boot from a partition more than 2TiB in, but you should still be able to boot as long as you boot from the front part of the disk. -- Brook pgpaN4uYFKOox.pgp Description: PGP signature
