On Tue, Nov 30, 2010 at 7:42 AM, Neil Brown <neilb@xxxxxxx> wrote: > If you are comparing recovering after some sort of problem with > a RAID10 over 6 devices compared with LVM over 2 2-device RAID1s, then the > former is certainly easier. This is simply because there are less layers of > complexity where something could go wrong. > > In both cases, your data will be spread across multiple disks, and any one > disk or even any two disks would be of no use to you. Thanks Neil. Still true with LVM on top of the 6-drive set in either case? Scenario being All the drives are together and OK (generic SATA2, cleanly disconnected) - but everything else is gone Not practical to rebuild the whole set of hosts, just want to get at key data Mount the disks on a new machine, boot from SystemRescueCD or Knoppix and copy the key data off. And between RAID6 and RAID10? > On Mon, 29 Nov 2010 23:00:19 +0700 hansbkk@xxxxxxxxx wrote: > >> 2010/11/29 Keld Jørn Simonsen <keld@xxxxxxxxxx>: >> >> I can see how RAID6 is simpler than RAID10, but compared to RAID1? >> > >> > Hmm, does not compute by me. RAID1 and RAID10 are the same in complexity, >> > RAID10 is just a modern RAID1, and should actually have been called >> > RAID1. >> >> My understanding is that if I use RAID10 on a single pair of disks >> then that is literally the same as RAID1. These to me are very simple >> in that I can take either one of the pair and mount it on any normal >> machine and get at the data without doing anything special. >> >> However, if I have my six disks configured as a single RAID10 array, I >> believe this is no longer true - the data from (at least the larger >> of) the files has been distributed over all six disks, correct? >> >> Now compare putting LVM on top of this array, compared to three RAID1 >> pairs on the one hand and a RAID6 array on the other (third) hand :) >> >> If I were trying to recover the data using the latest version of a >> LiveCD - say Fedora or Knoppix, which would be easier? >> >> I'm not trying to score any points, it's a genuine question. -- 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
