Hi all If I use nfsroot boot the xen dom0, I find it works well if not use initrd-2.6.32.9.img. what does "initrd-2.6.32.9.img" contains? Thanks Lei -- "We learn from failure, not from success!" _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Pasi Kärkkäinen
2010-May-13 12:35 UTC
Re: [Xen-users] what does "initrd-2.6.32.9.img" contains
On Thu, May 13, 2010 at 04:40:33PM +0800, lei yang wrote:> Hi all > > If I use nfsroot boot the xen dom0, I find it works well if not use > initrd-2.6.32.9.img. > > what does "initrd-2.6.32.9.img" contains? >It''s the "initial ramdisk" for Linux kernel. It contains (some) driver modules for the kernel, and a script to load them and to mount the actual root filesystem and switch to it. All the distros nowadays compile drivers as modules (ie. not included in the kernel itself), and use the initrd image to load only the needed/required drivers at boot time. -- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, May 13, 2010 at 8:35 PM, Pasi Kärkkäinen <pasik@iki.fi> wrote:> On Thu, May 13, 2010 at 04:40:33PM +0800, lei yang wrote: > > Hi all > > > > If I use nfsroot boot the xen dom0, I find it works well if not use > > initrd-2.6.32.9.img. > > > > what does "initrd-2.6.32.9.img" contains? > > > > It''s the "initial ramdisk" for Linux kernel. It contains (some) driver > modules for the kernel, > and a script to load them and to mount the actual root filesystem and > switch to it. > > All the distros nowadays compile drivers as modules (ie. not included in > the kernel itself), > and use the initrd image to load only the needed/required drivers at boot > time. > >Thanks Pasi, I have another question, why we need this initrd ramdisk, because we can put the kernel module in the dir "/lib" of rootfs, if we ignor the initrd, it should work Lei> -- Pasi > >-- "We learn from failure, not from success!" _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Pasi Kärkkäinen
2010-May-13 15:46 UTC
Re: [Xen-users] what does "initrd-2.6.32.9.img" contains
On Thu, May 13, 2010 at 11:32:17PM +0800, lei yang wrote:> On Thu, May 13, 2010 at 8:35 PM, Pasi Kärkkäinen <[1]pasik@iki.fi> wrote: > > On Thu, May 13, 2010 at 04:40:33PM +0800, lei yang wrote: > > Hi all > > > > If I use nfsroot boot the xen dom0, I find it works well if not use > > initrd-2.6.32.9.img. > > > > what does "initrd-2.6.32.9.img" contains? > > > > It''s the "initial ramdisk" for Linux kernel. It contains (some) driver > modules for the kernel, > and a script to load them and to mount the actual root filesystem and > switch to it. > > All the distros nowadays compile drivers as modules (ie. not included in > the kernel itself), > and use the initrd image to load only the needed/required drivers at > boot time. > > > > Thanks Pasi, I have another question, why we need this initrd ramdisk, > because we can put the kernel module in the dir "/lib" of rootfs, if we > ignor the initrd, it should work >Because you can''t access the rootfs before you have the drivers loaded!! initrd contains the drivers required to access the *rootfs*. -- Pasi> Lei > > > > -- Pasi > > -- > "We learn from failure, not from success!" > > References > > Visible links > 1. mailto:pasik@iki.fi_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, May 13, 2010 at 11:46 PM, Pasi Kärkkäinen <pasik@iki.fi> wrote:> On Thu, May 13, 2010 at 11:32:17PM +0800, lei yang wrote: > > On Thu, May 13, 2010 at 8:35 PM, Pasi Kärkkäinen <[1]pasik@iki.fi> > wrote: > > > > On Thu, May 13, 2010 at 04:40:33PM +0800, lei yang wrote: > > > Hi all > > > > > > If I use nfsroot boot the xen dom0, I find it works well if not > use > > > initrd-2.6.32.9.img. > > > > > > what does "initrd-2.6.32.9.img" contains? > > > > > > > It''s the "initial ramdisk" for Linux kernel. It contains (some) > driver > > modules for the kernel, > > and a script to load them and to mount the actual root filesystem > and > > switch to it. > > > > All the distros nowadays compile drivers as modules (ie. not > included in > > the kernel itself), > > and use the initrd image to load only the needed/required drivers at > > boot time. > > > > > > > > Thanks Pasi, I have another question, why we need this initrd ramdisk, > > because we can put the kernel module in the dir "/lib" of rootfs, if > we > > ignor the initrd, it should work > > > > Because you can''t access the rootfs before you have the drivers loaded!! > initrd contains the drivers required to access the *rootfs*. > >aha, Thanks, that''s the good answer, today, I boot a dom0 without initrd gPXE> dhcp net0 DHCP (net0 00:15:17:b0:01:76).... ok gPXE> kernel del/xen-4.0.0 module 17906/kernel root=/dev/nfs rw nfsroot=128.224.165.20:/export/17906/rootfs ip=dhcp console=ttyS0,115200 enforcing=0 gPXE> boot it boot well, maybe some drivers is not compiled "Y" not "M", I''m not sure which kernel module is need before access rootfs Thanks Lei> -- Pasi > > > Lei > > > > > > > > -- Pasi > > > > -- > > "We learn from failure, not from success!" > > > > References > > > > Visible links > > 1. mailto:pasik@iki.fi >-- "We learn from failure, not from success!" _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Pasi Kärkkäinen
2010-May-13 15:54 UTC
Re: [Xen-users] what does "initrd-2.6.32.9.img" contains
On Thu, May 13, 2010 at 11:52:55PM +0800, lei yang wrote:> On Thu, May 13, 2010 at 11:46 PM, Pasi Kärkkäinen <[1]pasik@iki.fi> wrote: > > On Thu, May 13, 2010 at 11:32:17PM +0800, lei yang wrote: > > On Thu, May 13, 2010 at 8:35 PM, Pasi Kärkkäinen > <[1][2]pasik@iki.fi> wrote: > > > > On Thu, May 13, 2010 at 04:40:33PM +0800, lei yang wrote: > > > Hi all > > > > > > If I use nfsroot boot the xen dom0, I find it works well if > not use > > > initrd-2.6.32.9.img. > > > > > > what does "initrd-2.6.32.9.img" contains? > > > > > > > It''s the "initial ramdisk" for Linux kernel. It contains (some) > driver > > modules for the kernel, > > and a script to load them and to mount the actual root filesystem > and > > switch to it. > > > > All the distros nowadays compile drivers as modules (ie. not > included in > > the kernel itself), > > and use the initrd image to load only the needed/required drivers > at > > boot time. > > > > > > > > Thanks Pasi, I have another question, why we need this initrd > ramdisk, > > because we can put the kernel module in the dir "/lib" of rootfs, > if we > > ignor the initrd, it should work > > > > Because you can''t access the rootfs before you have the drivers loaded!! > initrd contains the drivers required to access the *rootfs*. > > > aha, Thanks, that''s the good answer, today, I boot a dom0 without initrd > > gPXE> dhcp net0 > DHCP (net0 00:15:17:b0:01:76).... ok > gPXE> kernel del/xen-4.0.0 module 17906/kernel root=/dev/nfs rw > nfsroot=128.224.165.20:/export/17906/rootfs ip=dhcp console=ttyS0,115200 > enforcing=0 > gPXE> boot > > it boot well, maybe some drivers is not compiled "Y" not "M", I''m not sure > which kernel module is need before access rootfs >If you''re able to boot without initrd then your NIC and NFS drivers are built-in instead of modules. When booting from local disks you need to have the disk controller and filesystem driver modules loaded from initrd, possibly also software-raid and lvm drivers. -- Pasi> Thanks > Lei > > > > > -- Pasi > > Lei > > > > > > > > -- Pasi > > > > -- > > "We learn from failure, not from success!" > > > > References > > > > Visible links > > 1. mailto:[3]pasik@iki.fi > > -- > "We learn from failure, not from success!" > > References > > Visible links > 1. mailto:pasik@iki.fi > 2. mailto:pasik@iki.fi > 3. mailto:pasik@iki.fi_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
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