Hi Lennart, Hi Simon A proper understanding of mdadm is required. Hurrying with focus on codes for biochemical applications has brought me into a mess.
Relying of all my data, and special compiled programs, present on another raid1 amd64 wheezy, I carried out a reinstall of amd64 wheezy on the machine with new HD. mdo (boot, ext20, md1 (LVM, home, usr, etc). GRUB was installed on /dev/sda Then the command grub-install /dev/sdb with reported installation compete. No errors reported. On rebooting, GRUB was no more found, entering in grub rescue > which should also be known accurately, because prefix/root/ are now wrong. The only care I exerted, was not to work with the machine where I have my data, until the damaged machine is in order again. At any event, how to install safely GRUB on both disks of a RAID1 is a must. Thanks for your kind advice. francesco pietra As to mdadm, On Sat, Mar 2, 2013 at 7:05 AM, Simon Vos <simon...@gmail.com> wrote: > Have you assembled you raid devices again (mdadm --assemble /dev/mdX > /dev/sdX)? > > That should still work with the disk that was used for your RAID-1, when > that's done you can mount your disk, chroot into it and run grub-install > /dev/sda (and grub-install /dev/sdb, so you won't have this problem in the > future ;-)). > > > On 2 March 2013 11:10, Francesco Pietra <chiendar...@gmail.com> wrote: >> >> A further piece on information. With knoppix 7.0, the procedure for >> examining mdadm arrives at >> >> cat /proc/partitions >> sda >> sdb >> >> RAID1 (md0 md1) is not seen. I assume that this is the way Knoppix >> behaves in this situation. >> >> Thanks >> francesco pietra >> >> >> ---------- Forwarded message ---------- >> From: Francesco Pietra <chiendar...@gmail.com> >> Date: Sat, Mar 2, 2013 at 10:11 AM >> Subject: Re: RAID1 all bootable >> To: Lennart Sorensen <lsore...@csclub.uwaterloo.ca>, amd64 Debian >> <debian-am...@lists.debian.org>, debian-users >> <debian-user@lists.debian.org> >> >> >> Is this recipe devised for installing grub on both sda and sda with an >> undamaged RAID1? >> >> In my case, with the sda that contained grub loader replaced by a new >> disk, the rescue mode (using the same CD installer for amd64 wheezy) >> did not find any partition. Inverting the SATA cables, same result. >> >> In both cases (I mean position of SATA cables) I went to the shell in >> the installer environment: >> >> #fisk /dev/sda (or sdb) >> device contains neither a valid DOS partition table, nor Sun, etc >> (expected for a raid) >> >> #dmesg |grep -i sd >> sda (and sbb): unknown partition table (expected for a raid), however >> md: raid0 >> md: raid1 >> were identified, along with rai4, 5, 6 etc (unfortunately "| less" >> does not work to see the whole message). >> >> Am I using the Rescue Mode improperly? I was unable to dig into the HD >> that contains md0 (booth loader, EXT2) and md1 ( LVM partitions home >> tmp usr opt var swap EXT3) >> >> Thanks a lot for your kind advice >> >> francesco pietra >> >> >> >> On Fri, Mar 1, 2013 at 10:35 PM, Lennart Sorensen >> <lsore...@csclub.uwaterloo.ca> wrote: >> > On Fri, Mar 01, 2013 at 08:20:09PM +0100, Francesco Pietra wrote: >> >> Hi: >> >> With a raid1 amd64 wheezy, one of the two HDs got broken. >> >> Unfortunately, I had added grub to sda only, which is just the one >> >> broken. So that, when it is replaced with a fresh HD, the OS is not >> >> found. Inverting the SATA cables of course does not help (Operative >> >> System Not Found). In a previous similar circumstance, I was lucky >> >> that the broken HD was the one without gru. >> >> >> >> Is any way to recover? perhaps through Knoppix? I know how to look >> >> into undamaged RAID1 with Knoppix. >> >> >> >> Also, when making a fresh RAID1 from scratch, where to find a Debian >> >> description of how to make both sda and sdb bootable? (which should >> >> be included by default, in my opinion) >> > >> > You can boot the install disk in rescue mode, select the root partition >> > to chroot into, then run grub-install from there. >> > >> > When grub asks where to install, you should configure it for both sda >> > and sdb. I think 'dpkg-reconfigure grub-pc' is where that is selected. >> > Might need it to use -plow to asks all levels of questions. Not sure. >> > >> > -- >> > Len Sorensen >> >> >> -- >> To UNSUBSCRIBE, email to debian-amd64-requ...@lists.debian.org >> with a subject of "unsubscribe". Trouble? Contact >> listmas...@lists.debian.org >> Archive: >> http://lists.debian.org/caev0nmtmhadi2e_uk+wf+c0k9d1ygn3tv91jsr4g2ppp5_a...@mail.gmail.com >> > -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/caev0nmtuc4i2swgdq_bgge+-_uks7ywxveg2xmynyoynjxi...@mail.gmail.com
