I built a RAID5 array with 4 2Tb devices a few month ago.- I used LVM2 to build partitions.- I also used GRUB2.- Finally I installed Debian.For an unknown reason the RAID failed.The BIOS see only two devices. I am aware that my RAID is lost.For the two failed devices smart tool return nothing.1) with the reduced RAID array:is it possible to retrieve logical volumes and backup them ?is it possible to separate them, I mean to have two devices and not one RAID of two devices, and retrieve data ?2) When I try to boot with the two good devices, grub rescue takes the control.The ls command gives:  (hd0) (hd0,msdos1) (hd1) (hd1,msdos1) (md/0)ls .../boot gives unknown filesystemls (md/0) gives error disk 'md/0' not found.3) I boot an old device and install on it the HDDsupertool application.This application detects the failed disk by the command:hddsupertool -data1 - cff0 cf7e cfa0 1 wdc2003FYYS-02w0b1But this application is complicate and I don't know if I could retrieve data.Any ideas I could retrieve data or repair RAID ...Thanks
RAID5-4 devices with 2 failed devices: hope to retrieve data?
linux;grub2;hard disk;lvm;raid5