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Maxim Rozin
Frequent Advisor


Hello people,

I am trying to set up a diskless environment using netboot on redhat. After booting, the server got ip address using DHCP.
After showing some output, it ended up with this error:
RAMDISK: compressed image found at block 0
VFS: mounted root (ext2 filesystem) readonly.
freeing unused kernel memory: 176k freed
kernel panic - not syncing: no init found. try passing init= option to kernel.

Here is what I did to set up this netboot environment:
Reference system (linux02)
• Installed Redhat AS 4 update 1 for i386 (all the file systems are ext2)
• Installed busybox-anaconda-1.00.rc1-5 rpm

NFS server (linux01)
• Installed Redhat AS 4 update 1 for i386 (all the file systems are ext2)
• Created a new logical volume with ext2 file system on it for /diskless
• Created the directory /diskless/i386/RHEL4-AS/root
• Copied the OS from the reference system to the NFS server (rsync -a -e ssh linux02:/ /diskless/i386/RHEL4-AS/root/)
• Installed the tftp-server rpm and enabled it in xinetd
• Installed the dhcp rpm and created /etc/dhcpd.conf that contains the following:
##/etc/dhcpd.conf begins here##
ddns-update-style interim;
ignore client-updates;
allow booting;
allow bootp;

#Each segment should have a specific subnet section
subnet netmask
option routers; #gateway
option subnet-mask; #subnet mask
option domain-name-servers; #DNS

range dynamic-bootp; #IP range to be allocated
default-lease-time 21600;
max-lease-time 43200;

class "pxeclients"
match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
next-server; #tftp server
filename "linux-install/pxelinux.0";
##/etc/dhcpd.conf ends here##

• Added the following to /etc/exports and started the service:
/diskless/i386/RHEL4-AS/root/ *(ro,sync,no_root_squash)
/diskless/i386/RHEL4-AS/snapshot/ *(rw,sync,no_root_squash)

• Installed system-config-netboot rpm
• Configured the diskless environment using system-config-netboot. As a result, initrd.img and vmlinuz were created in /tftpboot/linux-install/rhel-4-as-u1-i386-32/. Also, /diskless/i386/RHEL4-AS/snapshot/ directory was created with a file called files in it.
• Added a host using system-config-netboot. As a result, in the existing snapshot/ directory in the diskless directory, a subdirectory was created with the Snapshot name specified as the file name. All of the files listed in snapshot/files were copied copy from the root/ directory to this new directory. Also, a file called C0A801C8 was created in /tftpboot/linux-install/pxelinux.cfg/. It contains the following:
default rhel-4-as-u1-i386-32

label rhel-4-as-u1-i386-32
kernel rhel-4-as-u1-i386-32/vmlinuz
append initrd=rhel-4-as-u1-i386-32/initrd.img root=/dev/ram0 init=disklessrc NFSROOT= ramdisk_size=10000 ETHERNET=eth0 SNAPSHOT=netboot01

That's it.
Does anyone has an idea of what the problem is?


Re: netboot

it is the problem with your initrd.img file.

follow the steps in the below given site