Por favor, lenguaje en Español > Date: Wed, 26 Jan 2011 17:24:36 +0000 > From: [email protected] > To: [email protected] > Subject: [Bug 569900] Re: partman sometimes creates partitions such that > there is ambiguity between whether the superblock is on the disk > device or the partition device > > There are other way to get this bug too and it will haunt us back in the > future and not only within Ubuntu > > It hit me when partitionising with fdisk -u /dev/sdx but not with fdisk > /dev/sdx because the first fits tightly to the end of the drive, the > second leaves some space. The same happened when using GPT through > cfdisk (not sure, its been a while). > > All in all it shouldn't be wrong to use a tightly fitting partition > table. The real problem here is that a 0.9 superblock can not be > reliably source to either a device or a partition (or a LVM, actually I > can imagine scenarios where its not only about drive or partition but in > addition about other mappings like LVM, crypt, hey, even a stupidily > placed part of a filesystem could qualify as a superblock). Until now it > worked because scanning for superblock accidentially used a less error > prone sequence for scanning (in fact even then the scanning usually ran > head first into a wall but accidentially this didn't get through to the > user) > > In short: Placing vital information at the end of a bunch of sectors and > hoping for a successful poking-around by the startup is stupid and prone > for error. > > Everyone should use front-aligned superblocks, that is version 1.1 > and/or 1.2 because every known mapping (LVM, MD, Crypt, filesystems) are > able to preserve lead-in-gaps and deliver this vital information to the > next layer. Not so for for lead-out-gaps. > > -- > You received this bug notification because you are subscribed to Ubuntu > ubuntu-10.04.2. > https://bugs.launchpad.net/bugs/569900 > > Title: > partman sometimes creates partitions such that there is ambiguity > between whether the superblock is on the disk device or the partition > device > > Status in “grub2” package in Ubuntu: > Invalid > Status in “partman-base” package in Ubuntu: > Fix Released > Status in “grub2” source package in Lucid: > Invalid > Status in “partman-base” source package in Lucid: > Fix Released > Status in “grub2” source package in Maverick: > Invalid > Status in “partman-base” source package in Maverick: > Fix Released > > Bug description: > Binary package hint: mdadm > > In a KVM, I can do this just fine: > > * Using 2 virtual disk images > * Install Lucid Server amd64 > * Both disks partitioned to just one large Linux raid partition > * RAID1 these two together, /dev/md0 > * Put / on an ext4 filesystem on /dev/md0 > * Install > > The above works. > > However, I have spent my entire weekend trying to get 10.04 on a RAID1 > of two 500GB SATA disks, without success. > > I partitioned them the same as above. And conducted the install. > > When I boot into the new system, I get dropped to an initramfs shell. > > I can see that /dev/md0 exists, and is in the process of resyncing. > > I try to "mount /dev/md0 /root" and I get: > mount: mounting /dev/md0 on /root/ failed: Invalid argument > > Also, see something else that's odd... My /dev/md0 looks "correct", > in that it's composed of /dev/sda1 and /dev/sdb1. However, I also see > a /dev/md0p1, which is composed of /dev/sda and /dev/sdb (the whole > disks?). Furthermore, if I go into /dev/disk/by-uuid, there is only > one symlink there, pointing to /dev/md0p1. And this UUID is what is > in fact in grub as the root device. That looks quite wrong. > > This looks pretty release-critical, to me, as it's affecting RAID > installs of the server. > > TEST CASE: The above problem should arise when attempting a RAID > install on any disk whose size is between 1048576*n+512 and > 1048576*n+65535 bytes, for integer values of n. In order to reproduce > this, the root filesystem should be created on a RAID array whose > member devices extend all the way to the end of the disk (i.e. accept > the default size for the partition in the installer). > > To validate this from -proposed (once available), please note that you > will need to use a netboot installation image and boot with apt- > setup/proposed=true on the kernel command line. > >
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/569900 Title: partman sometimes creates partitions such that there is ambiguity between whether the superblock is on the disk device or the partition device -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
