On Sun, Jul 07, 2002 at 02:47:21PM -0400, Paul Clements wrote: > On Fri, 5 Jul 2002, Martin Hermanowski wrote: > >> I've made a raid1 mirror of an lvm partition and an nbd from another >> machine. Then I created an ext3 fs on it. > > I've not tried this with LVM, but have done similar things with a SCSI disk > partition and nbd device under raid1. There are a few bugs in these > drivers that could lead to the scenario you describe below (recovery stuck > at 0% and never progressing). Which kernel are you using? Unfortunately, > I think just about every currently available Linux distribution kernel > has these problems (save maybe the Red Hat Advanced Server 2.4.9 kernel). > But the good news is that the problems should be fixed in 2.4.19, which > will be available soon. I'm using a vanilla 2.4.18. >> This all works quite well, but after about 6~12 disconnects and >> reconnects of the nbd (disc-failures for the raid) while the recovery >> thread is working, the recovery thread is show as folling in >> /proc/mdstat: >> | [>....................] recovery = 0.0% (0/16777152) >> | finish=461360.7min speed=0K/sec > > I have seen this same symptom. It turns out that this is due to some bugs > in the raid1 driver. These problems were especially bad on SMP machines. This is a single-cpu system, I think this only happens if there is lot of writing, I could'nt reproduce it without this. > So I'm fairly certain that you're running into the same problems that > I discovered a few months ago. There are also some minor issues in the > nbd driver that might be contributing to the problem. > > I can give you some patches that will most likely fix these problems, if > you are willing/able to patch your kernel. Or, as I said, you can wait until > 2.4.19 is available. I surely would like to try this. Thanks for your explanation. I will post the results with your patches/with 2.4.19 when available. >> Is there any way to stop the recovery thread manually? > > No. Because of the locking that is performed in the raid1/md drivers, there > is no way to stop a device that is in the middle of recovery since it is > marked "busy". > > -- > Paul Clements > SteelEye Technology > Paul.Clements@SteelEye.com > > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
