Thank you Dave for your answer,
On this pc I had a real trouble because I couldn't import with zpool import - f rpool,but I tryed on another PC yesterday and the installation was succesfull and I was able to import the rpool.(so it does'nt matter now I will use the pc on which the installation was succesfull)
On the both PC I have another trouble: I cannot install the solaris grub2 in the MBR with bootadm install-bootloader -fMv -P rpool c7d0s0 (I have 3 hards disks and the first is c7d0 and the 3rd disk is solaris c8d0), it says GRUB2 installation failed
the syntax is bootadm install-bootloader -FM ....... device, so is c7d0s0 right ? the first hard disk is a MBR disk with a linux system (ext4),
I've tryed too to chainload solaris with two versions of grub2 of linux but it doesn't boot solaris (I had done a bootadm install-bootloader -fv -P rpool before)
I could perhaps try too to install solaris on the first hard disk so the grub2 would perhaps install easily in the MBR ?
it' is a little bit long booting with the text installer cd , if you have a solution for installing grub2 of solaris into the MBR, I take it