One correction: I actually made the MDS box into a RAID-10 array (using the 6 drives).
The seven OSD boxes use RAID-0 however. Although, I'm not really sure if that matters (probably not...). -Brock -----Original Message----- From: Erwin, Brock A Sent: Friday, June 06, 2008 12:08 PM To: 'Sage Weil' Subject: RE: [ceph-devel] kernel crashes when trying to use 'dd' to overwrite a file Sage, I am using 8 machines total. They are HP boxes, all running linux kernel 2.6.24.7-92.fc8 (Fedora Core 8). They all have AMD Quad core processors, so the architecture is x86_64. Each box has 8 hard-drives total. 2 of the drives are dedicated for the linux kernel. The other six I have made into a RAID-0 array using software. I used 'mdadm' to configure it, so it looks like a block device on /dev/md0. One of the boxes I then formatted /dev/md0 to ext3 and mounted it, which I then used to put the monitor files on. (I used your wiki page on "Small test cluster" in order to figure out how to do that). Then I configured the remaining 7 boxes to be OSDs, running "cosd --mkfs_for_osd [0-7] /dev/md0" on each of the boxes. Of course, I then ran "cosd /dev/md0 -d --debug_osd 10" on each of the boxes to start up the daemon process. I'm not sure if you need any other information, so let me know. -Brock -----Original Message----- From: Sage Weil [mailto:[EMAIL PROTECTED] Sent: Friday, June 06, 2008 11:53 AM To: Erwin, Brock A Cc: ceph-devel@lists.sourceforge.net Subject: Re: [ceph-devel] kernel crashes when trying to use 'dd' to overwrite a file Hi Brock- > $ dd if=/dev/zero of=foo bs=1M count=1024 > > < CRASH! > Can you tell me a bit about the system you're on? I haven't been able to replicate this on my machines. Can you reliably reproduce it? >From the flags I suspect it's a race related to truncation. Can you let me know if this fixes it? 0670d2a: kclient: ClearPagePrivate more aggressively in invalidatepage Thanks- sage > > > > It seems that when 'dd' tries to overwrite a file, crash! Below is some > kernel output... > > > > Message from [EMAIL PROTECTED] at Jun 6 11:06:04 ... > > kernel: Bad page state in process 'dd' > > > > Message from [EMAIL PROTECTED] at Jun 6 11:06:04 ... > > kernel: page:ffffe200080ba358 flags:0x0248100000000800 > mapping:0000000000000000 mapcount:0 count:0 (Tainted: G B ) > > > > Message from [EMAIL PROTECTED] at Jun 6 11:06:04 ... > > kernel: Trying to fix it up, but a reboot is needed > > > > Message from [EMAIL PROTECTED] at Jun 6 11:06:04 ... > > kernel: Backtrace: > > > > ..... > > > > Bad page state in process 'dd' > > page:ffffe20007d41f60 flags:0x0238100000000800 mapping:0000000000000000 > mapcoun) > > Trying to fix it up, but a reboot is needed > > Backtrace: > > > > Thanks, > > -Brock > > ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Ceph-devel mailing list Ceph-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ceph-devel
