Why am I losing so much disk space with Linux (vs Windows)?
I'm a relative newbie with Linux, but fairly advanced otherwise. I previously had my media server setup with a hardware RAID card (the LSI Logic Megaraid i4) on Windows XP using Maxtor 300GB ATA drives. I recently filled my array, and have been playing around with Linux software RAID as a possible platform for my server.
The "300GB" Maxtors have a raw capacity of 283 GB. With hardware RAID under Windows XP, an NTFS formatted 7-disk RAID-5 array yielded a storage capacity of 1.67 TB. (which amounts to ~ 278 GB /disk) Also a non-raided drive yields the same 278 GB size after NTFS formatting.
Using Fedora Core 3, I created a 4-disk RAID-5 array using ext3 file system with the same 300 GB Maxtor drives. I was shocked to see my available capacity was only 783 GB (261 GB/disk). I installed the root and swap partitions on a separate system disk, so there is no usage of the array by the system. "df -h" indicates a size of 838 GB for the array, but with 1% usage and only 783 GB available? What happened to those 55 GB? Does the ext3 file system eat that much space? I was planning on running a 12-disk array ultimately, but with this difference in capacity, it is almost worth buying Windows Server 2003 and using its software RAID instead...