* RAID 6 offers higher level of data protection RAID 6 covers more basesBy Charles EischenRAID technology — Redundant Array of Independent Disks — lets you establish varying degrees of data protection depending on the particular requirements of a given application. RAID levels 0, 1, 5 and 10 have been the most widely used, with RAID 5 (rotational parity) reigning supreme for fault tolerance because it allows data on a failed drive to be rebuilt without losing accessibility to stored information. RAID 6 (double parity) provides a higher level of fault tolerance by protecting data on two drives in the event of a failure. In a RAID 5 array data is striped across all drives and parity information is distributed and stored across all the disks. If a drive fails the surviving array operates in degraded mode until the failed drive is replaced and its data is rebuilt from the parity information. But all data will be lost in the event of a second drive failure during a rebuild or a latent media defect that causes a read error during the rebuild. Today’s increased hard disk capacities are causing longer rebuild times, which increases the likelihood that a second drive will fail during rebuild. RAID 6 eliminates that risk. In a RAID 6-enabled system a second set of parity is calculated, written and distributed across all the drives. This second parity calculation provides significantly more fault tolerance because two drives can fail without resulting in data loss.But the additional calculations required with RAID 6 adversely affect write performance. Performance benchmarks show a RAID controller can suffer more than a 30% drop in overall write performance compared with a RAID 5 implementation. RAID 5 and RAID 6 read performance are comparable. RAID suppliers implement their designs differently, so it is important to find controllers that minimize the RAID 6 write penalty. Look for controllers that make double parity calculations simultaneously and that use dedicated, silicon-based stripe handlers to reduce the write penalty radically.For more on this story, please click here.Eischen is senior marketing manager for AMCC’s storage division. He can be reached at ceischen@amcc.com. Related content how-to Compressing files using the zip command on Linux The zip command lets you compress files to preserve them or back them up, and you can require a password to extract the contents of a zip file. By Sandra Henry-Stocker May 13, 2024 4 mins Linux news High-bandwidth memory nearly sold out until 2026 While it might be tempting to blame Nvidia for the shortage of HBM, it’s not alone in driving high-performance computing and demand for the memory HPC requires. By Andy Patrizio May 13, 2024 3 mins CPUs and Processors High-Performance Computing Data Center opinion NSA, FBI warn of email spoofing threat Email spoofing is acknowledged by experts as a very credible threat. By Sandra Henry-Stocker May 13, 2024 3 mins Linux how-to Download our SASE and SSE enterprise buyer’s guide From the editors of Network World, this enterprise buyer’s guide helps network and security IT staff understand what Secure Access Service Edge (SASE) and Secure Service Edge) SSE can do for their organizations and how to choose the right solut By Neal Weinberg May 13, 2024 1 min SASE Remote Access Security Network Security PODCASTS VIDEOS RESOURCES EVENTS NEWSLETTERS Newsletter Promo Module Test Description for newsletter promo module. Please enter a valid email address Subscribe