I have a Dell xps 14 with dualboot windows 7 / ubuntu 12.10
on the windows side is active intel smart response ssd caching, while on the ubuntu side 11Gb ssd space is accessible as /dev/sdb1 . windows and ubuntu are installed in /dev/sda, while /dev/sdb is dedicated to caching and for bootloading.
Now the nasty part: while caching is active, windows can modify /dev/sdb's mbr, while ubuntu cannot. funny thing is, no errors are reported by grub while doing a grub-install.
Right now the only solution i found is to deactivate caching from windows, do my business on the mbr from ubuntu, and reactivate caching on the windows side.
also, while this setup worked for the last couple of weeks, suddenly linux is unable to find the root partition by uuid, because it sees all the uuid as 00000000-0000-0000-0000-000000000000. To workaround this i edit the kernel -root parameter from grub to point to /dev/sda5 instead of the default uuid value. When the system is ready, i can see the right uuid associated to each partition.
i already tried to add rootdelay=9 to the boot options but i's ineffective, I get the same Kernel Panic: error syncing VFS error.
i suspect that these problems are somewhat related, but i don't know where to start looking. So, any help is greatly appreciated!
additional info kernel: 3.7.0-7-generic dm-raid: i'm not sure what is the purpose and how it works, but it's mentioned alot online because my problem is related to the fakeraid created by intel :P