[CentOS] network raid file system/server

hi, we've a few 10-20 server in a lan each has 4-8 hdd. we'd like to create one big file server on these server hard disks and we'd like to create it in a redundant way ie: - if one (or more) of the hdd or server fails the whole filesystem still usable and consistent. - any server in this farm can see the same storage/filesystem. it's someting a big network raid5-6... storage where we have about 40<partition added to the same network volume. and there is an fs over it which hide all internal network raid functionality. is there any such solution? i can't find any way to do this on our linux servers. thank you for your help in advance.