I have a linux server with sda to host the OS (Ubuntu 7.04, ext3 filesystem) and sdb,sdc,sdd,sde 1TB each to be on a raid 1 for saving data. I need to get rid of the raid and I wanna swap it for a 4TB disk. How can I determine which is the max disk space that is supported?
Linux is not really the limiting factor when it comes to max disk size, as long as you stick to ext3,4 or xfs. If you are running a recent main board with SATA you are good to go, since SATA has 48bit LBA to address the disk.
Ext3 has some limits on max disk size, due to the chosen block size. With a block size of 4KiB the maximum file size is 2TiB and the max disk size 16TiB.
Another very insightful read is here: What is the max partition supported in linux?