On 11/21/2009 11:40 AM, Bruce Labitt wrote: > Bill, why not RAID-5? Isn't RAID-5 supposed to be ultra-reliable? As > in hot swap disks? Or does this just apply to software RAID-5... > > -Bruce > who knows very little about this RAID stuff...
RAID-5 itself has a problem known as the "RAID-5 write hole" where data loss can be guaranteed in certain situations. RAID-6 is a patch to prevent this. But RAID-5/6 also come with complexity, and software is buggy. The main advantage of RAID-5 is getting more disk space usable per dollar. But with cheap disk space under $80/TB RAID-1 (simple mirroring) gets you less complex reliability and better performance. And for a boot disk, having only one surviving drive is sufficient to get your machine running again. ZFS's RAID-Z is probably the exception to the rule as everything is round-trip checksummed, but I still wouldn't use it for a boot disk since a boot disk set doesn't need to be big enough to justify any cost savings. -Bill -- Bill McGonigle, Owner BFC Computing, LLC http://bfccomputing.com/ Telephone: +1.603.448.4440 Email, IM, VOIP: [email protected] VCard: http://bfccomputing.com/vcard/bill.vcf Social networks: bill_mcgonigle/bill.mcgonigle _______________________________________________ gnhlug-discuss mailing list [email protected] http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
