does it mean that my harddisk is broken?

sorry, not good at english

1.install 11.1 using a livecd from hd , and install nvidia driver & new kernel, reboot -> grub missing (it shows “error no operating system”)
2.install 11.0 from cd
3.install 11.1 from hd, and install nvidia driver & new kernel, reboot -> grub missing
4. fix grub with 11.0 cd, reboot -> grub works
5. remove the older kernel, and delete it in bootloader, reboot ->
grub missing
6. fix grub with 11.0 cd.

now i’m trying to install all updates to see if the grub will miss again……

BTW, these days i notice that when booting the system, it often says “filesystem not clean”

ok, grub still there.

but a new kernel-default is installed, maybe i didn’t remove it completely. now i’ll unistall it and delete it in bootloader, then check what’s going on.

ok, when i open the bootloader in yast, i fount the kernel default is gone. it seems that the last time manually edit the bootloader is not a good idea. completely remove the kernel will also delete its own item in grub?

Install normally, then boot from CD/DVD, go on until option ‘Boot installed system’ is available. Choose that, wait for system to be booted, hit Ctrl-Alt-F1, login as root and follow commands:
This will return the devices and their mount points. One is on “/” and named /dev/sdaX where X is a number, now do:
#grub-install /dev/sdaX where X is the number you found above.

Now grub is installed properly and you should be able to boot from hdd