On Thu, 13 Jan 2005, Neil Brown wrote: > There is no current support for raid6 in any 2.4 kernel and I am not > aware of anyone planning such support. Assume it is 2.6 only. How "real-life" tested is RAID-6 so-far? Anyone using it in anger on a production server? I've spent the past day or 2 getting to grips with kernel 2.6.10 and mdadm 1.8.0 on a test system running Debian Woody, on a rather clunky old test PC - Asus XG-DLS, Twin Xeon PIII/500's on-board IDE with 2 x old 4GB drives attached, it also has on-board Adaptec SCSI with 2 x 18GB drives - one on an 8-bit bus, and a Highpoint HPT302 card with 2 modern 80 GB drives (Maxtor, I know, but keep them cool and so-far so good...) Performance isn't exactly stellar (one PCI bus!) but I did squeeze 60MB/sec out of a RAID-0 off the 2 new drives... Clunky by todays standards, but 5.5 years ago when it was new, it rocked! Anyway, so far so good. I've constructed a RAID-6 system with a 4GB partition on 5 of the drives, and done some tests & what not. The tests I've done involve creating the array, putting a filesystem on it (ext3), writing a bigfile of zeros, checksumming it, failing a drive, adding it back in, failing another, failing a 2nd, adding them in, failing another before the 2nd drive finished resyncing, etc. all the time writing a file & checksumming it between unmounting & re-mounting it. There was a script posted round about July last year which I used to get some ideas from. So-far so good, no corruption, but it doesn't doesn't mean anything in the real-world. So who's using RAID-6 for real? Can it be considered more or less stable than RAID-5? Should I stick to my RAID-5 on-top of RAID-1 pairs? Or should I just take a chance with RAID-6? (And nearly 6 years ago when I started using Linux s/w RAID I said this to myself, but stuck with it and haven't had a problem I could pin down to software... So who knows!) Gordon - 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
