I'm happy to apply a patch to whichever kernel you like, but the blocks have since cleared, so I will try and reproduce it first. On Wed, 31 Aug 2011, NeilBrown wrote: >Date: Wed, 31 Aug 2011 17:38:42 +1000 >From: NeilBrown <neilb@xxxxxxx> >To: Chris Pearson <kermit4@xxxxxxxxx> >Cc: linux-raid@xxxxxxxxxxxxxxx >Subject: Re: dirty chunks on bitmap not clearing (RAID1) > >On Mon, 29 Aug 2011 11:30:56 -0500 Chris Pearson <kermit4@xxxxxxxxx> wrote: > >> I have the same problem. 3 chunks are always dirty. >> >> I'm using 2.6.38-8-generic and mdadm - v3.1.4 - 31st August 2010 >> >> If that's not normal, then maybe what I've done differently is that I >> created the array, raid 1, with one live and one missing disk, then >> added the second one later after writing a lot of data. >> >> Also, though probably not the cause, I continued writing data while it >> was syncing, and a couple times during the syncing, both drives >> stopped responding and I had to power off. >> >> # cat /proc/mdstat >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] >> [raid4] [raid10] >> md127 : active raid1 sdd1[0] sdc1[2] >> 1904568184 blocks super 1.2 [2/2] [UU] >> bitmap: 3/15 pages [12KB], 65536KB chunk >> >> unused devices: <none> >> >> # mdadm -X /dev/sd[dc]1 >> Filename : /dev/sdc1 >> Magic : 6d746962 >> Version : 4 >> UUID : 43761dc5:4383cf0f:41ef2dab:43e6d74e >> Events : 40013 >> Events Cleared : 40013 >> State : OK >> Chunksize : 64 MB >> Daemon : 5s flush period >> Write Mode : Allow write behind, max 256 >> Sync Size : 1904568184 (1816.34 GiB 1950.28 GB) >> Bitmap : 29062 bits (chunks), 3 dirty (0.0%) >> Filename : /dev/sdd1 >> Magic : 6d746962 >> Version : 4 >> UUID : 43761dc5:4383cf0f:41ef2dab:43e6d74e >> Events : 40013 >> Events Cleared : 40013 >> State : OK >> Chunksize : 64 MB >> Daemon : 5s flush period >> Write Mode : Allow write behind, max 256 >> Sync Size : 1904568184 (1816.34 GiB 1950.28 GB) >> Bitmap : 29062 bits (chunks), 3 dirty (0.0%) > >I cannot see how this would be happening. If any bits are set, then they >will be cleared after 5 seconds, and then 5 seconds later the block holding >the bits will be written out so that they will appear on disk to be cleared. > >I assume that if you write to the array, the 'dirty' count increases, but >always goes back to three? > >And if you stop the array and start it again, the '3' stays there? > >If I sent you a patch to add some tracing information would you be able to >compile a new kernel with that patch applied and see what it says? > >Thanks, > >NeilBrown > > >> >> >> Quoting NeilBrown <neilb@xxxxxxx>: >> >> > On Thu, October 15, 2009 9:39 am, aristizb@xxxxxxxxxxx wrote: >> >> Hello, >> >> >> >> I have a RAID1 with 2 LVM disks and I am running into a strange >> >> situation where having the 2 disks connected to the array the bitmap >> >> never clears the dirty chunks. >> > >> > That shouldn't happen... >> > What versions of mdadm and the Linux kernel are you using? >> > >> > NeilBrown >> > >> >> >> >> I am assuming also that when a RAID1 is in write-through mode, the >> >> bitmap indicates that all the data has made it to all the disks if >> >> there are no dirty chunks using mdadm --examine-bitmap. >> >> >> >> The output of cat /proc/mdstat is: >> >> >> >> md2060 : active raid1 dm-5[1] dm-6[0] >> >> 2252736 blocks [2/2] [UU] >> >> bitmap: 1/275 pages [12KB], 4KB chunk, file: /tmp/md2060bm >> >> >> >> >> >> The output of mdadm --examine-bitmap /tmp/md2060bm is: >> >> >> >> Filename : md2060bm >> >> Magic : 6d746962 >> >> Version : 4 >> >> UUID : ad5fb74c:bb1c654a:087b2595:8a5d04a9 >> >> Events : 12 >> >> Events Cleared : 12 >> >> State : OK >> >> Chunksize : 4 KB >> >> Daemon : 5s flush period >> >> Write Mode : Normal >> >> Sync Size : 2252736 (2.15 GiB 2.31 GB) >> >> Bitmap : 563184 bits (chunks), 3 dirty (0.0%) >> >> >> >> >> >> Having the array under no IO, I waited 30 minutes but the dirty data >> >> never gets clear from the bitmap, so I presume the disks are not in >> >> sync; but after I ran a block by block comparison of the two devices I >> >> found that they are equal. >> >> >> >> The superblocks and the external bitmap tell me that all the events >> >> are cleared, so I am confused on why the bitmap never goes to 0 dirty >> >> chunks. >> >> >> >> How can I tell if the disks are in sync? >> >> >> >> >> >> Thank you in advance for any help >> -- >> 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
