That is exactly what I didn't want to hear :( I am running 2.6.26-2-xen-amd64. Are you sure its a kernel problem and nothing to do with my chunk/block sizes? If this is a bug what versions are affected, I'll build a new domU kernel and see if I can get it working there. - chris On Sun, Feb 21, 2010 at 12:48 AM, Neil Brown <neilb@xxxxxxx> wrote: > On Sat, 20 Feb 2010 23:33:23 -0500 > chris <tknchris@xxxxxxxxx> wrote: > >> Hello, >> >> I am trying to setup a raid 5+0 on 6 1TB sata disks. I created the >> arrays like so: >> >> mdadm --create /dev/md2 --level=5 --raid-devices=2 /dev/sda /dev/sdb /dev/sdc >> mdadm --create /dev/md3 --level=5 --raid-devices=2 /dev/sdd /dev/sde /dev/sdf >> mdadm --create /dev/md4 --level=0 --raid-devices=2 /dev/md2 /dev/md3 >> >> The arrays create and sync fine, then I put lvm on top and create a >> volume group and everything seems fine. I created 2 logical volumes >> and formatted them with filesystems and initially didn't realize >> anything was wrong. After running 2 virtual machines on them for a >> while I noticed the vm's were reporting bad blocks on the volume. I >> looked in the dom0 dmesg and found tons of messages such as: >> >> [444905.674655] raid0_make_request bug: can't convert block across >> chunks or bigger than 64k 69314431 4 > > This looks like a bug in 'dm' or more likely xen. > Assuming you are using a recent kernel (you didn't say), raid0 is > receiving a request that does not fit entirely in on chunk, and > which has more than on page in the bi_iovec. > i.e. bi_vcnt != 1 or bi_idx != 0. > > As raid0 has a merge_bvec_fn, dm should not be sending bios with more than 1 > page without first cheking that the merge_bvec_fn accepts the extra page. > But the raid0 merge_bvec_fn will reject any bio which does not fit in > a chunk. > > dm-linear appears to honour the merge_bvec_fn of the underlying device > in the implementation of its own merge_bvec_fn. So presumably the xen client > is not making the appropriate merge_bvec_fn call. > I am not very familiar with xen: how exactly are you making the logical > volume available to xen? > Also, what kernel are you running? > > NeilBrown > > >> >> Chunksize for both raid5's and the raid0 is 64k so it would appear the >> issue is not that the chunk size is greater than 64k. I also find it >> hard to believe it could be any kind of lvm issue simply because the >> message in dmesg clearly shows its related to the raid0. >> >> Any ideas on what I'm missing here would be greatly appreciated. I >> would imagine it is some kind of alignment between block and chunk >> sizes but I can't seem to figure it out :) >> >> More detailed information including raid information and errors is at >> http://pastebin.com/f6a52db74 >> >> - chris >> -- >> 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 > > -- 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
