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
I have installed solaris on the first hard drive as I couldn't install grub2 solaris in the MBR of the first hard drive when solaris was on the third hard drive,and now grub2 is installed in the MBR of the first hard drive
Now I haven't any problem any more with this configuration...