Below are the steps to recover the kernal panic issue in Oracle Exadata machines
Take the diagnostics ISO from the working server and map it in faulty server then boot that server using that ISO and follow the below steps
mkdir /mnt/LVDbSys1
mkdir /mnt/LVDbSys2
mount /dev/mapper/VGExaDb-LVDbSys1 /mnt/LVDbSys1
mount /dev/mapper/VGExaDb-LVDbSys2 /mnt/LVDbSys2
vi /mnt/LVDbSys1/var/log/cellos/dbnodeupdate.log
vi /mnt/LVDbSys2/var/log/cellos/dbnodeupdate.log
go to end of the line - compare the time stamp. which is latest.
e2label /dev/mapper/VGExaDb-LVDbSys1 - check the label
e2label /dev/mapper/VGExaDb-LVDbSys2
ls -al /mnt/LVDbSys2
e2label /dev/mapper/VGExaDb-LVDbSys2 ''
e2label /dev/mapper/VGExaDb-LVDbSys1 DBSYS
e2label /dev/mapper/VGExaDb-LVDbSys1- check the label
e2label /dev/mapper/VGExaDb-LVDbSys2
mkdir /mnt/boot
ls -lrt /mnt/boot
mount /dev/sda1 /mnt/boot
df -h
tar cvf /mnt/LVDbSys1/failed_boot.tar /mnt/boot
ls -lrt /mnt/LVDbSys1
rm -rf /mnt/boot/*
tar -pjxvf /mnt/LVDbSys1/boot_backup.tbz -C /mnt
echo "(hd0) /dev/sda" > /tmp/grubmap
/sbin/grub --device-map=/tmp/grubmap
find /I_am_hd_boot
root (hd0,0)
setup (hd0)
quit
sync
umount /mnt/LVDbSys1
umount /mnt/LVDbSys2
umount /mnt/boot
disconnect the CD-ROM image from the Devices menu
Take the diagnostics ISO from the working server and map it in faulty server then boot that server using that ISO and follow the below steps
mkdir /mnt/LVDbSys1
mkdir /mnt/LVDbSys2
mount /dev/mapper/VGExaDb-LVDbSys1 /mnt/LVDbSys1
mount /dev/mapper/VGExaDb-LVDbSys2 /mnt/LVDbSys2
vi /mnt/LVDbSys1/var/log/cellos/dbnodeupdate.log
vi /mnt/LVDbSys2/var/log/cellos/dbnodeupdate.log
go to end of the line - compare the time stamp. which is latest.
e2label /dev/mapper/VGExaDb-LVDbSys1 - check the label
e2label /dev/mapper/VGExaDb-LVDbSys2
ls -al /mnt/LVDbSys2
e2label /dev/mapper/VGExaDb-LVDbSys2 ''
e2label /dev/mapper/VGExaDb-LVDbSys1 DBSYS
e2label /dev/mapper/VGExaDb-LVDbSys1- check the label
e2label /dev/mapper/VGExaDb-LVDbSys2
mkdir /mnt/boot
ls -lrt /mnt/boot
mount /dev/sda1 /mnt/boot
df -h
tar cvf /mnt/LVDbSys1/failed_boot.tar /mnt/boot
ls -lrt /mnt/LVDbSys1
rm -rf /mnt/boot/*
tar -pjxvf /mnt/LVDbSys1/boot_backup.tbz -C /mnt
echo "(hd0) /dev/sda" > /tmp/grubmap
/sbin/grub --device-map=/tmp/grubmap
find /I_am_hd_boot
root (hd0,0)
setup (hd0)
quit
sync
umount /mnt/LVDbSys1
umount /mnt/LVDbSys2
umount /mnt/boot
disconnect the CD-ROM image from the Devices menu