HDD - Getting More Bandwidth
Originally written by
- The first thing was getting more throughput (or bandwidth)
- This was achieved by combining disks in groups.
- This is usually done by using disk striping
- which is the simplest form of RAID (RAID 0)
- If 1 disk = 100MB/second, 10 disks = 1GB/second.
- With many disks - the chance of a failure increase
- Thus protection schemes were formed:
- Mirroring - RAID 1 - no performance penalty.
- parity protection - RAID 4 - parity (re)calculations slow down writes.
- Alternating Parity protection - RAID 5
- dual-failure parity protection - RAID 6.
- Combining mirroring with striping - RAID 10.