On Thu, 17 May 2012 09:37:50 -0600 Marcus Sorensen <shadowsor@xxxxxxxxx> wrote: > First off, I'm using the stock RHEL 6.2 kernel, so obviously not the > latest, but I want to get some input on a strange issue I'm seeing. > Maybe it rings a bell and someone knows a fix or a specific kernel to > try. Could I get that a as linux-kernel version number? RHEL numbers don't mean anything to me. > > I have a few RAID 1 arrays that while resyncing refuse to use the > bandwidth allowed to them. I'm using an internal bitmap. My impression > was that the various sync speed settings are supposed to use all > available bandwidth, backing off if there is other system activity. > The disks are capable of syncing at 400MB/s, and my sync_speed_min is > set to 10000, sync_speed_max is set to 500000, yet they sync at > ~80MB/s and iostat shows the disks as being mostly idle. If I > increase sync_speed_min to 200000, the array happily complies and > resyncs at 200MB/s, no problem. 400MB/s!! SSDs?? The "is the device idle" algorithm was quite fragile for a while there, though I feel that was quite a while ago. So it might be a known problem but I would need the kernel version to be sure. > > Also, I seem to have run into an issue similar to the following > thread, where failing a disk, then restarting the array and re-adding > the disk results in a full resync. I'll see if I can replicate via the > included instructions. > > http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg08745.html > > Last, I've been reading bits about a bad block bitmap, and if I'm > going to a newer kernel I want to make sure I'm not using one. My > understanding was that I have to use a new version of the mdadm > userspace utility to even create an array with a bad block bitmap, and > even then it's not on by default, correct? It isn't a bitmap, it is a list. And it needs to be explicitly enabled by mdadm, and no released version of mdadm does that. I don't know yet what the default will be once I do add that support properly. Suggestions welcome. NeilBrown > > Thanks > -- > 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
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