On Mon, Jan 19, 2009 at 3:00 PM, Jon Nelson <jnelson-linux-raid@xxxxxxxxxxx> wrote: > I guess what I'd like to see more than anything else is not raid5 or > raid6 but raidN where N can be specified at the start and grown. While > I'm not a fan of ZFS's rulebreaking one thing it does (or claims to > do) strikes me as "the future" - the ability to specify X protection > bits and to increase or decrease X as needs see fit. It also strikes > me that there are several ways to do this but fundamentally it boils > down to "we don't trust our drives anymore and there we wish to > protect our data against their failure". Given 5 or 10 or 50 drives > how does one really protect their data effectively and allow their > data pool to grow without large quantities of hoop-jumping? > > I'd really like to see a re-thinking of data protection (parity or > data duplication) at the block layer - it need not be RAID as we know > it but IMO something has to be done - rapidly do we near the > precipice! If I understand what your saying, HP started supporting "Raid Equivalent" protection in some of their storage arrays years ago. You simply put a bunch of disk drives in the unit, then tell you want a 50GB logical volume with Raid 5 equivalent protection, etc. I think it might for example allocate 10 GB from each of 6 disk drives. (ie. 5 for data + 1 for parity). Then you ask for 30 GB with raid 10 equivalent protection and it might allocate 10GB more from those same 6 drives. Then you go back and increase the size of th 50GB raid5 and it would allocate more space on the drives as required, but always ensuring the data was protected at least at raid5 levels. I sort of thought of it as an integrated LVM and Raid manager. I suspect putting that together is a pretty large amount of effort. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
