Date: Tue, 31 Jan 2017 12:58:47 -0800 (PST) From: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> To: "Andrey V. Elsukov" <bu7cher@yandex.ru> Cc: Warren Block <wblock@wonkity.com>, freebsd-hackers@freebsd.org, Slawa Olhovchenkov <slw@zxy.spb.ru> Subject: Re: How to safely remove rest of GTP? Message-ID: <201701312058.v0VKwlut046163@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <515e709a-5c34-0bc1-bc3b-7cff99f6dd97@yandex.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
> On 31.01.2017 18:43, Rodney W. Grimes wrote: > > ... much deleted ... > >> > >>> It is impossible to have a corrupted GPT and some > >>> other type of partition table in the same time. > > > > I believe that statement is in error. > > dd if=/boot/boot0 of=/dev/ada0 > > Would not that lead to this very situation if done > > to a GPT parted disk drive? > > No, it will not lead to this situation. > /boot/boot0 is similar to /boot/mbr in the example, and with /dev/ada0 > all will behaves like with /dev/md0. Well if that is the case then the GPT backup copy is... well useless as I just clobbered the MBR of a drive and now gpart is gona just take that as fine and dandy? Doesnt that defeat the purpose of the backup GPT? > >> Maybe when only using FreeBSD and gpart, but I'm pretty sure I've seen > >> forum users who have tried some crappy other formatting tool and have > >> overwritten the primary GPT with a valid MBR and left the secondary GPT > >> untouched. This only becomes obvious when they bring the disk back to a > >> FreeBSD system. > > > > As almost all MBR tools are un aware of GPT so well not do anything to > > destroy the secondary GPT, so this is infact very likely to occur. > > Please, give me some working example, when or where you have a problem, > and not some theoretical, based on previous negative experience or memories. Next time I see one I well be sure to preserve it, but I have seen problems with bad interactions between GPT and MBR. -- Rod Grimes rgrimes@freebsd.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201701312058.v0VKwlut046163>