read my earlier mails ... it is silly , but not as silly as trying to modify the kernel code for just one specific disk : ) On Sat, 13 Nov 2004 13:59:19 +0100, Peter T. Breuer <ptb@lab.it.uc3m.es> wrote: > ashwin chaugule <ashwin.chaugule@gmail.com> wrote: > > (please do not top post - fixing. Please take note!) > > > > > > > Is this correct if I want data to be mirrored across all 4 partitions > > > > , using RAID 1 on a single disk ? > > > > > > So, you are talking about a mirror with 4 components, all of them > > > partitions on the same disk? > > > > > > Well, that's silly, but nothing stops you doing it. Just maek a raidtab > > > for the mirror and name the partitions as raid-disk components there. > > > The RAID howto or faq should tell you all you need to know, as should > > > the mananpage for the conf file or mdadm, or whatever ... > > > ok so, i also do know, its performance is going to suck ! > > No, it'll be fine - merely a couple or more times slower at writing > large streams. In ordinary use you may sometimes see more latency, but > provided you aren't streaming or running synchronous writes, you > shouldn't notice. What's silly is that there's no point in doing it - > you get no protection against the disk disappearing, because all the > mirror components are on the same disk. > > It's like making 3 sets of spare housekeys, and then putting them all > in the same keyholder as the original set, and walking around like that. > > Silly, no? > > > but i was under the impression that RAID 1 works on more that one disks only. > > I don't understand you. While a mirror with only one component is > trivial, it is a mirror. > > > so you mean to say that, the linux RAID / md tools support raid 1 on > > multiple partitiions of the same disk ? > > Nobody cares where the mirror components are physically sited except > you. Why should any tool care? Its job is to do what you say. I don't > understand why you should think that the tool would even know (well, > there is a chance that it could look and check, but I don't recall any > significant code in the driver dedicated to optimizations based on that). > > > > Peter > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > -- Ashwin Chaugule Embedded Systems Engineer Aftek Infosys ltd. [Embedded Division] _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
