From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory L Shomo Subject: Re: parent transid troubles Date: Wed, 04 May 2011 14:04:51 -0400 Message-ID: References: <1303332799-sup-9175@think> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs@vger.kernel.org To: Chris Mason Return-path: In-Reply-To: <1303332799-sup-9175@think> (message from Chris Mason on Wed, 20 Apr 2011 16:54:23 -0400) List-ID: Chris Mason writes: >> Mounting the filesystem read-only from /dev/sdd1 fails, but >> succeeds from /dev/sdc1... after about 4855 parent transid >> verification failures. >> >> kernel: [ 293.827069] Btrfs loaded >> kernel: [ 293.828014] device fsid 2e4187db574846d8-404f05c2e6ec579d devid 2 transid 176065 /dev/sdd1 >> kernel: [ 293.828781] btrfs: failed to read the system array on sdd1 >> kernel: [ 293.835956] btrfs: open_ctree failed >> >> kernel: [ 305.296345] device fsid 2e4187db574846d8-404f05c2e6ec579d devid 1 transid 176066 /dev/sdc1 >> kernel: [ 305.476360] parent transid verify failed on 20403515125760 wanted 176066 found 174710 >> kernel: [ 305.476608] parent transid verify failed on 20403515125760 wanted 176066 found 174710 >> !-- snip >> >> Is there any chance we can resolve some of the parent transid >> verification failures ? What should our next steps be ? >> >> Thank you very much for all your help. > > The failures won't get resolved easily. Many of them will be duplicates > because of the way we do readahead. > > Step one is to copy off the data that you can. dmesg -n 1 will help > prevent performance problems from message floods. > > -chris So we've copied off all the data, what's the next step ? Losing all files that were open for writing at the time of the failure is no problem, as those data sets will have to be re-computed anywise. Does that work in our favour to resolve this issue ? - greg