I'm having 3 Sata drive in a RAID5 system.
RAID5 is working as Parity checking, a file is sliced in parts, each parts are located on 2 of the 3 drives. If a drive is dead, changing it with a new one allow reconstruction of the data, thus preventing data lost from a dead drive.
How is physically working the fragmentation on a raid5 ? is a given file located at the same place (TOC, and physically) on each drives ?
I've always been afraid to use O&O defrag on my raid'ed logical drives, because I don't know if it will mess the RAID parity, as the same file is maybe not physically located on the same place on each SATA, moving a cluster in a low access of the drive may destroy the parity (if O&O look for each SATA drives independently instead of a logical created RAID drive).
Has anybody tested O&O defrag with a parity RAID system ?
Or maybe defrag is unnecessary on a RAID5 drive, because all chunk of data are physically located everywhere on the drive (they have slower access than non RAID drive). This is a system working on a fragmentation system, and can't be defragged ?
I'm thinking there's no advantage at all, as the system (windows) is seeing data as "unfragmented" on the logical RAID drive, but the real data on each SATA are fragmented, the physical location of data is managed by the BIOS.