My 3rd sata drive
in [Linux Help]
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From: unruh on 6 Jun 2010 18:27 On 2010-06-06, nomail@_INVALID_no.org <nomail@_INVALID_no.org> wrote: > On 06/05/2010 01:54 PM, Pascal Hambourg wrote: >> Hello, >> >> nomail@_INVALID_no.org a ?crit : >>>>> >>>>> If there is a 3rd drive plugged in >>>>> >>>>> "Waiting for device /dev/sdX to appear: could not find device /dev/sdX >>>>> Want me to fall back to /dev/sdY? (Y/n)" >>>>> >>>>> If any 2nd drive is not in position-2: >>>>> >>>>> "Kernel panic - not syncing: Attempted to kill init!" >>>>> >>>>> Any hints would be appreciated. I tried to disable all IDE (pata) >>>>> features in bios but it doesn't seem to make any difference :-( >> >> I suspect udev messed up again when something changed. >> How is the root= defined in /boot/grub/menu.lst ? > > Always as root=/dev/sdaXx I am sorry, but why are you being coy? It is not sdaXx but something substituted in for that Xx. Why not tell us? > >> Anything about sd* in the kernel log (can you drop a shell and run dmesg >> in the initramfs) ? > > Tomorrow maybe, the main drive is hooked to a notebook for the night. > >>> Doesn't the kernel load the partition tables on boot from bios? >> >> No. It loads them itself. The BIOS does not know anything about partitions. The bios knows only about sector and cylinders. Everything else is the operating system and file system driver. The partition table is part of the MBR, the first 1KB on the disk >
From: Java Jive on 6 Jun 2010 19:55 Just to clarify for anyone who is any doubt, this is how an OS is booted from disk on a PC: http://www.macfh.co.uk/JavaJive/PCHardware/PCBootProcess/PCBootProcess.html On Sun, 06 Jun 2010 22:27:36 GMT, unruh <unruh(a)wormhole.physics.ubc.ca> wrote: > > On 2010-06-06, nomail@_INVALID_no.org <nomail@_INVALID_no.org> wrote: > > > > On 06/05/2010 01:54 PM, Pascal Hambourg wrote: > >> > >> nomail@_INVALID_no.org a ?crit : > >>> > >>> Doesn't the kernel load the partition tables on boot from bios? > >> > >> No. It loads them itself. The BIOS does not know anything about partitions. > > The bios knows only about sector and cylinders. Everything else is the > operating system and file system driver. > The partition table is part of the MBR, the first 1KB on the disk -- ========================================================= Please always reply to ng as the email in this post's header does not exist. Or use a contact address at: http://www.macfh.co.uk/JavaJive/JavaJive.html http://www.macfh.co.uk/Macfarlane/Macfarlane.html
From: nomail on 7 Jun 2010 12:52 On 06/06/2010 01:52 AM, J.O. Aho wrote: > nomail@_INVALID_no.org wrote: >> On 06/05/2010 02:40 PM, J.O. Aho wrote: >>> nomail@_INVALID_no.org wrote: >> >> Gee, thanks for the extensive writ! >> >> >>>> Grub deals in terms of hd0, hd1, hd2, hd3. Breaking into grub with "c" >>>> and doing the "root (hdx,y)" command also shows how grub sees the drives >>>> and partitions. I booted a grub floppy with 4 drives plugged in and can >>>> confirm that on this board grub sees them all exactly and correctly in >>>> sequence same as bios does. >>> >>> The mapping is done in /boot/grub/device.map and may lack mapping for those >>> two later hard drives. >> >> >> Can't use map files cause drives are swinging in/out like chopper blades >> most of the time. >> >>>> The one surprise here was that the top 40gb #15 partition on my 2tb >>>> drive is too high for bios and for grub. >>> >>> Think there was some kind of limitation on the number of partitions in 0.9x >>> Grub (but I may mistaken). >> >> With SATA drives I've been using up to 15 partitions and if I remember >> correctly even more than that with PATAs. > > Grub isn't Linux, they don't work in the same way and those can have > differences (hardware can also make differences, like a PowerPC based machine > may support far more than 4 primary partitions, but this ain't the problem for > you). > > You haven't thought of using LVM, with so many partitions, you are prone to > run out of space a lot easier, with LVM you could assign more space in a quite > simple way, you can create snapshots if you are experimenting, so you can > return to a state before the experiment, or even mirroring data (if you use > more than one hard drive). The main difference between RAID and LVM is hat you > can have different settings for each LVM while RAID you have to select one > kind for each array. > > >>> Another thing that could make disks to "switch" order is >>> "spin up time", if your hard drive is damaged and your kernel don't use the >>> data from BIOS, then it can take longer for it to say "Hi" and therefore will >>> get a higher device name. >> >> No labels, I use strictly /dev/name. Disk id might work but I do a lot >> of mirroring with dd and it would be just too complicated. > > It's just one more command to run, not really that much complicated and using > labels and setting them correctly could have saved you from this problem. > > >>>> Just looking at the sequence shown in the earlier install episode it >>>> strikes me that sda-sdb ........sdg-sdh has a 4 disk gap in addition to >>>> a wrong sequence. >>> >>> Can much be some odd udev rule, check that you don't have an odd persistent >>> udev rule or persistent-cd rule which has already used up the sdc - sdf. >>> Another reason can be that your motherboard has 4 SATA and 2 SATA-RAID, where >>> the pots for the SATA gets sda - sdd, while those connected to the SATA-RAID >>> will get sde-sdh. >> >> I looked at the manual and it just talks 4 sata connectors which are >> numbered 1-4. I don't see any raid connectors as such, raid setup is in >> BIOS. > > Check that your "sda" is really connected to SATA1, so you haven't just at > some point put it in SATA4 and then changed boot order in BIOS. > This would explain why the booting don't work with your 3 disks setup, you > read the kernel from the machine with the kernel in hd0,0, but the kernel will > see the other disk as /dev/sda and that one does lack your high partition. I'll check this out, for now i'm busy prepping a eeeeeeeeeeeeeepc :-) The other idea of reading the dmsg is probably a good one too, not that I could understand most of it. The question is how to recover it? Every suspect boot is incomplete by definition and by the time I get a good one the boot message has been overwritten. Maybe if I boot another partition the second time with only two disks and then fish out the dmsg from the first? > Your motherboard most likely has "two" SATA, which makes you to get a jump in > device numbering. > > >>>> I have no more pata drives but still need one ribbon for >>>> the DVD burner. >>> >>> Do a "ls -l /dev/cdrom" to see which device it really uses or check the >>> persistent-cd rule. >> >> I've pulled the optical burner and will use it externally on usb. Then >> I'll look for a way to completely disable everything PATA that I find >> (later). > > The usb CD-rom will become an /dev/sdX and that one can cause you a lot more > trouble. Keep the PATA CD-rom unit, so that you get less confusing/randomness > with your devices. > > >
From: nomail on 7 Jun 2010 14:07 When grub2 arrives (already has with Debian-500, Suse follows in July) it will use 1 for the first disk but 0 for the first partition OR VICE VERSA, I forget :-)))
From: J.O. Aho on 7 Jun 2010 14:09
nomail@_INVALID_no.org wrote: > On 06/06/2010 01:52 AM, J.O. Aho wrote: >>> I looked at the manual and it just talks 4 sata connectors which are >>> numbered 1-4. I don't see any raid connectors as such, raid setup is in >>> BIOS. >> >> Check that your "sda" is really connected to SATA1, so you haven't just at >> some point put it in SATA4 and then changed boot order in BIOS. >> This would explain why the booting don't work with your 3 disks setup, you >> read the kernel from the machine with the kernel in hd0,0, but the kernel will >> see the other disk as /dev/sda and that one does lack your high partition. > > I'll check this out, for now i'm busy prepping a eeeeeeeeeeeeeepc :-) > > The other idea of reading the dmsg is probably a good one too, not that > I could understand most of it. The question is how to recover it? Every > suspect boot is incomplete by definition and by the time I get a good > one the boot message has been overwritten. Maybe if I boot another > partition the second time with only two disks and then fish out the dmsg > from the first? Much depends on your distro, some distros do save the dmesg to /var/log/dmesg and then you can read /var/log/dmesg.X what happen previous times you booted. -- //Aho |