Re: Kernel Configuration Question
On 12/23/06 11:25:25AM -0600, Mike Reinehr wrote: > On Saturday 23 December 2006 09:35, Jim Crilly wrote: > > On 12/22/06 12:10:41PM -0600, Mike Reinehr wrote: > > > I hate to answer my own posting but it belatedly has occurred to me that > > > perhaps it's not possible to mount a root partition using LVM without an > > > initrd.img. I've booted without an initrd.img before & I've used LVM > > > before, but not with the root partition as part of the logical volumes. > > > Yes, no, maybe? > > > > That's pretty much it, you need to run the LVM tools (vgchange I think) to > > scan for and setup the logical volumes. There is no code in the kernel to > > do that for you so you have to use an initramfs image if your root is on > > LVM. But why go through all of that trouble to not use one? The only burden > > it puts on you is to run 'update-initramfs -u -k ' on of > > the off chance that you change something that also needs to go in the > > image, normal updates to things like LVM tools, udev, etc should update it > > for you. > > > > Jim. > > Thanks for confirming this. I think I may have read something about this last > year when I first researched LVM but then forgot. > > As for not using an initrd.img, long ago I became a confirmed follower of the > KISS theory of operations (Keep It Simple, Stupid) and was just trying to > pare my kernel of any unnecessary pieces. But, as you say, it's not that much > trouble to maintain an initrd.img. > Exactly, it's virtually 0 maintenance unless you're doing really odd, complex things in your initramfs and even then once you set it up and put the files under /etc/initramfs-tools/ it'll keep working. A decent example is this, I setup this box with some dm-crypt block devices and by default the generic aes module is used, to switch to aes_x86_64 all I had to do was put the module name in /etc/modules, update my initramfs and reboot, if they had been compiled in statically I would have been stuck recompiling my kernel for that. And with the kernel people wanting to push more and more device discovery and setup to userland it's going to be unavoidable at some point anyway. Jim. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Kernel Configuration Question
On Saturday 23 December 2006 09:35, Jim Crilly wrote: > On 12/22/06 12:10:41PM -0600, Mike Reinehr wrote: > > I hate to answer my own posting but it belatedly has occurred to me that > > perhaps it's not possible to mount a root partition using LVM without an > > initrd.img. I've booted without an initrd.img before & I've used LVM > > before, but not with the root partition as part of the logical volumes. > > Yes, no, maybe? > > That's pretty much it, you need to run the LVM tools (vgchange I think) to > scan for and setup the logical volumes. There is no code in the kernel to > do that for you so you have to use an initramfs image if your root is on > LVM. But why go through all of that trouble to not use one? The only burden > it puts on you is to run 'update-initramfs -u -k ' on of > the off chance that you change something that also needs to go in the > image, normal updates to things like LVM tools, udev, etc should update it > for you. > > Jim. Thanks for confirming this. I think I may have read something about this last year when I first researched LVM but then forgot. As for not using an initrd.img, long ago I became a confirmed follower of the KISS theory of operations (Keep It Simple, Stupid) and was just trying to pare my kernel of any unnecessary pieces. But, as you say, it's not that much trouble to maintain an initrd.img. Cheers! cmr -- Debian 'Etch': Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Kernel Configuration Question
On 12/22/06 12:10:41PM -0600, Mike Reinehr wrote: > > I hate to answer my own posting but it belatedly has occurred to me that > perhaps it's not possible to mount a root partition using LVM without an > initrd.img. I've booted without an initrd.img before & I've used LVM before, > but not with the root partition as part of the logical volumes. Yes, no, > maybe? > That's pretty much it, you need to run the LVM tools (vgchange I think) to scan for and setup the logical volumes. There is no code in the kernel to do that for you so you have to use an initramfs image if your root is on LVM. But why go through all of that trouble to not use one? The only burden it puts on you is to run 'update-initramfs -u -k ' on of the off chance that you change something that also needs to go in the image, normal updates to things like LVM tools, udev, etc should update it for you. Jim. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Kernel Configuration Question
On Friday 22 December 2006 11:43, Mike Reinehr wrote: > Would someone please help me with what, I think, should be a fairly simple > kernel configuration question. I am attempting compile a new AMD64 kernel > that will boot without using an initrd.img file. I've done this a number of > times before, but this time I can't seem to get it working. Every time, I > end up with a kernel panic, unable to mount root device. > > First, I have a pair of SATA drives set up in a RAID 1 configuration, two > primary partitions (EXT3) and GRUB installed in the boot sector. The first > partition is mounted as /boot. The second partition is set up as a physical > volume group within which are defined the > usual /root, /home, /var, /usr, /tmp & swap as logical volumes. All this > was set up with the latest Debian-Installer beta (Etch RC1) and boots > perfectly with a stock kernel (linux-image-2.6.18-3-amd64). > > I've tried to locate all of the modules necessary to boot and compile them > into the kernel, but I must be missing something. > > When I attempt to boot with my kernel, > 1) GRUB locates and boots the kernel from /boot; > 2) The SATA drives are recognized; > 3) md & device-mapper modules are initialized; > 4) The RAID arrays are recognized; > md: Autodetecting RAID arrays > md: autorun ... > md: ... autorun DONE. > but then: > > VFS: Cannot open root device "mapper/vg0-root_lv" or unknown block(0,0) > Please append a correct "root=" boot option > Kernel panic - not syncing: VFS: Unable to mount root fs on > unknown-block(0,0) > > I considered adding a "root=" boot option, as the message said, > but /dev/mapper/vg0_root_lv is the correct logical volume. > > As a post script, I just noticed that when I have a successful boot, the > RAID arrays are announced as they are recognized, where as with my kernels, > it just says "autorun" followed by "autorun DONE". If that means that the > RAID arrays are _not_ being recognized then I have no idea why. > > TIA > > CMR I hate to answer my own posting but it belatedly has occurred to me that perhaps it's not possible to mount a root partition using LVM without an initrd.img. I've booted without an initrd.img before & I've used LVM before, but not with the root partition as part of the logical volumes. Yes, no, maybe? -- Debian 'Etch': Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Kernel Configuration Question
Would someone please help me with what, I think, should be a fairly simple kernel configuration question. I am attempting compile a new AMD64 kernel that will boot without using an initrd.img file. I've done this a number of times before, but this time I can't seem to get it working. Every time, I end up with a kernel panic, unable to mount root device. First, I have a pair of SATA drives set up in a RAID 1 configuration, two primary partitions (EXT3) and GRUB installed in the boot sector. The first partition is mounted as /boot. The second partition is set up as a physical volume group within which are defined the usual /root, /home, /var, /usr, /tmp & swap as logical volumes. All this was set up with the latest Debian-Installer beta (Etch RC1) and boots perfectly with a stock kernel (linux-image-2.6.18-3-amd64). I've tried to locate all of the modules necessary to boot and compile them into the kernel, but I must be missing something. When I attempt to boot with my kernel, 1) GRUB locates and boots the kernel from /boot; 2) The SATA drives are recognized; 3) md & device-mapper modules are initialized; 4) The RAID arrays are recognized; md: Autodetecting RAID arrays md: autorun ... md: ... autorun DONE. but then: VFS: Cannot open root device "mapper/vg0-root_lv" or unknown block(0,0) Please append a correct "root=" boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) I considered adding a "root=" boot option, as the message said, but /dev/mapper/vg0_root_lv is the correct logical volume. As a post script, I just noticed that when I have a successful boot, the RAID arrays are announced as they are recognized, where as with my kernels, it just says "autorun" followed by "autorun DONE". If that means that the RAID arrays are _not_ being recognized then I have no idea why. TIA CMR -- Debian 'Etch': Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
