andre999 wrote: > blind Pete a écrit : >> andre999 wrote: >> >> >>> blind Pete a écrit : >>> >>>> David W. Hodgins wrote: >>>> >>>> >>>> >>>>> On Fri, 06 Jul 2012 04:03:34 -0400, blind Pete >>>>> <[email protected]> wrote: >>>>> >>>>> >>>>> >>>>>> Morgan Leijström wrote: >>>>>> >>>>>> >>>>>>> It would also be interesting to know what other tools say. >>>>>>> gparted? >>>>>>> >>>>>>> >>>>> >>>>> >>>>>> Gparted looks pretty. As far as I can see, gparted agrees >>>>>> with what I think things should look like. Gparted and >>>>>> fdisk agree about the number of sectors. (More than you >>>>>> get by multiplying CxHxS.) >>>>>> >>>>>> >>>>> Interesting. I guess it would be best to use 'hdparm -i /dev/sda|grep >>>>> LBAsects" to find out the number of sectors. >>>>> >>>>> Regards, Dave Hodgins >>>>> >>>>> >>>> [root@live ~]# hdparm -i /dev/sda | grep LBA >>>> CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=1953523055 >>>> [root@live ~]# >>>> >>>> Same number of sectors as gparted and fdisk report. Number of heads >>>> and sectors per cylinder are just, "it's a big disk". _Posssibly_ >>>> number of cylinders gives a clue about how big. H can be 63 or 255, >>>> depending on mood, and CxHxS should be a little less than max LBA. >>>> >>>> The situation just got worse. The latest work arround is to lie >>>> about how big a sector is. That is called "advanced" formatting. >>>> >>>> > >>> BTW, with all those partitions, I would convert your disk to GPT tables >>> instead of MBR, using gdisk. >>> (gdisk is in core.) >>> >> OK I have installed gdisk and will look at it. How would you rate >> it for maturity? And what else can recognize a gpt disk? > > I would say very mature, even when I started using it (under mdv 2010.0 > or 2010.1) > The developer says the "hybid" option which simulates MBR for Msw is > risky, but even that I found very stable and predictable
I let it loose on my test machine. It has Lilo on the mbr. Mageia 1 with Grub in its root partition, Mageia 2 with Grub in its root partition, and Ubuntu 10.04.4 with Grub 2 in its root partition. Converting to gpt confused Ubuntu's Grub 2. Experimenting with a hybrid system, converting a primary to a logical, adding a new primary, and renumbering confused lots of things. It was only the test computer. >> Grub? >> > Yes, since 1.97 patched for GPT, as used in mdv and fedora (at least) > when I started using GPT. > Mageia has always used this version. >> Grub2? >> > Definitely I managed to confuse it. Posibly by having it installed in the root partition. >> Lilo? >> > Not sure. I think newer versions do. Mostly works. The mbr code just jumps to a hardcoded sector address and loads the real code from what is normally /etc/map. >> The Mageia installer? >> > I didn't have a problem. I did an upgrade install from mdv2010.2 to > mga1, and could read the other partitions to set up fstab. > Sometime before mga1 was available, I had a problem which corrupted my > system, and made it unbootable. It took me a while to get around that, > as I didn't want to loose my uncorrupted partitions. I ended up fixing > it with SystemRescueCD (it contains a partition recovery tool called > testdisk.) I was able to reinstall mdv. I may have formatted / with > SystemRescueCD. At that point I had a "hybrid" format simulating MBR > for systems not aware of GPT. Is there any option in the installer to turn the disk into a gpt disk? >> Other installers? >> >> Other operating systems? >> > According to what I have read, most other major distros handle GPT > nicely. The Linux kernel does. > Msw 32-bit does not, but can work with gdisks' "hybrid" format, which > puts an MBR table at the end of the first sector (a space not used by > GPT). It is a little tricky to set up, but initially I had it working. > Recently I haven't been bothered to get it working again. > Msw 64-bit is GPT-aware, but I have read that it works only on EFT > hardware, which has a special BIOS. (Incompatible with Msw 32-bit.) It > may be just that it is the default installation. > MacOS handles GPT, but I'm not sure of the restrictions if any. Is was > an early adopter. > *BSD systems should handle GPT just like Linux. >>> It will make your disk more stable. >>> It uses a 128 partition table,with a backup table at the end of the >>> drive. No such thing as "extended" partitions. >>> It takes less space than the ms-compatible MBR partition tables. >>> The only trick is that you need to leave space for the backup table (34 >>> 512-byte sectors). >>> If you change your mind, you can convert back painlessly. >>> I've used GPT for over 2 years, including converting back and forth a >>> few times at first. >>> >>> To convert, you'll have to boot to a live disk, preferably with gdisk. >>> I use systemRescueCD for that. http://www.sysresccd.org/ >>> The latest stable version is 379 Mib, usable from CD or USB key. >>> I don't know if a Mageia live cd, or Mageia DVD in rescue mode might >>> work. >>> >> In Mageia 1 the installer pulled it from the net rather than from >> the local iso, so it was not prepackaged. > > I installed mga1 from DVD. This upgrade went very smoothly. > > I did have a problem changing partition parameters with diskdrake under > mga1, not long after installing it, shortly after mga1 was released. > Luckily I was testing things, so I didn't loose anything important. But > everything was lost on the partition in question. I then tried > reformatting the partition with diskdrake, and it wouldn't work. I had > to use SystemRescueCD (with gparted). > I strongly suspect it was due to my having a "hybrid" format. I think > that at least at that point, diskdrake (or whatever it uses) would see > the MBR table, and classify the disk as MBR. While still getting the > partition location parameters from the GPT table. (The simulated MBR > table puts most partitions in a large "foreign" partition. The > corrupted partition was not in the MBR table. And no other partition > was affected.) > > Note that I have never had a problem simply accessing (read or write) a > GPT partition on mdv or mga. > > Also, initially I used gdisk to format usb drives (but no hybrid MBR > table), and have never had a problem on those disks with diskdrake or > any other mdv or mga tools. > > BTW, I installed gdisk from upstream on mdv, and first imported gdisk to > Mageia. >>> Just in case you might be interested >>> >> I'm interested. > > You will probably find this interesting :) > http://en.wikipedia.org/wiki/GUID_Partition_Table Thanks. -- blind Pete Sig goes here...
