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</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi guys,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> <span lang=EN-CA>I was wondering there was some better way of wiping the content of an old EBS volume before actually deleting the logical volume in cinder ? Or perhaps, configure or add the possibility to configure the number of parallel “dd” processes that will be spawn at the same time…<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>Sometimes, users will simply try to get rid of their volumes ALL at the same time and this is putting a lot of pressure on the SAN servicing those volumes and since the hardware isn’t replying fast enough, the process then fall in D state and are waiting for IOs to complete which slows down everything.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>Since this process isn’t (in my opinion) as critical as a EBS write or read, perhaps we should be able to throttle the speed of disk wiping or number of parallel wipings to something that wouldn’t affect the other read/write that are most probably more critical.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Here is a small capture of the processes :<o:p></o:p></span></p><p class=MsoNormal>cinder 23782 0.7 0.2 248868 20588 ? S Oct24 94:23 /usr/bin/python /usr/bin/cinder-volume --config-file /etc/cinder/cinder.conf --logfile /var/log/cinder/volume.log<o:p></o:p></p><p class=MsoNormal>cinder 23790 0.0 0.5 382264 46864 ? S Oct24 9:16 \_ /usr/bin/python /usr/bin/cinder-volume --config-file /etc/cinder/cinder.conf --logfile /var/log/cinder/volume.log<o:p></o:p></p><p class=MsoNormal><span lang=EN-CA>root 32672 0.0 0.0 175364 2648 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--2e86d686--de67--4ee4--992d--72818c70d791 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32675 0.0 0.1 173636 8672 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--2e86d686--de67--4ee4--992d--72818c70d7<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32681 3.2 0.0 106208 1728 ? D 21:48 0:47 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--2e86d686--de67--4ee4--992d--72818c70d791 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32674 0.0 0.0 175364 2656 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--d54a1c96--63ca--45cb--a597--26194d45dcdf count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32676 0.0 0.1 173636 8672 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--d54a1c96--63ca--45cb--a597--26194d45dc<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32683 3.2 0.0 106208 1724 ? D 21:48 0:47 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--d54a1c96--63ca--45cb--a597--26194d45dcdf count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32693 0.0 0.0 175364 2656 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--048dae36--b225--4266--b21e--af4b66eae6cd count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32694 0.0 0.1 173632 8668 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--048dae36--b225--4266--b21e--af4b66eae6<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 32707 3.2 0.0 106208 1728 ? D 21:48 0:46 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--048dae36--b225--4266--b21e--af4b66eae6cd count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 342 0.0 0.0 175364 2648 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--45251e8e--0c54--4e8f--9446--4e92801976ab count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 343 0.0 0.1 173636 8672 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--45251e8e--0c54--4e8f--9446--4e92801976<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 347 3.2 0.0 106208 1728 ? D 21:48 0:45 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--45251e8e--0c54--4e8f--9446--4e92801976ab count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 380 0.0 0.0 175364 2656 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--1d9dfb31--dc06--43d5--bc1f--93b6623ff8c4 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 382 0.0 0.1 173632 8668 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--1d9dfb31--dc06--43d5--bc1f--93b6623ff8<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 388 3.2 0.0 106208 1724 ? R 21:48 0:45 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--1d9dfb31--dc06--43d5--bc1f--93b6623ff8c4 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 381 0.0 0.0 175364 2648 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--60971d47--d3c5--44ef--9d43--d461c364d148 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 384 0.0 0.1 173636 8672 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--60971d47--d3c5--44ef--9d43--d461c364d1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 391 3.2 0.0 106208 1728 ? D 21:48 0:45 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--60971d47--d3c5--44ef--9d43--d461c364d148 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 383 0.0 0.0 175364 2648 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--856080db--4f8c--4063--9c47--69acb8460e50 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 386 0.0 0.1 173632 8668 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--856080db--4f8c--4063--9c47--69acb8460e<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 389 3.1 0.0 106208 1724 ? D 21:48 0:45 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--856080db--4f8c--4063--9c47--69acb8460e50 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 385 0.0 0.0 175364 2652 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--f8f98d80--044f--4d4a--983f--d1186556f886 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 387 0.0 0.1 173632 8668 ? S 21:48 0:00 | | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--f8f98d80--044f--4d4a--983f--d1186556f8<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 392 3.1 0.0 106208 1728 ? D 21:48 0:45 | | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--f8f98d80--044f--4d4a--983f--d1186556f886 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 413 0.0 0.0 175364 2652 ? S 21:48 0:00 | \_ sudo cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--0e89696a--492b--494c--81fa--7e834b9f31f4 count=102400 bs=1M co<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 414 0.0 0.1 173636 8672 ? S 21:48 0:00 | \_ /usr/bin/python /usr/bin/cinder-rootwrap /etc/cinder/rootwrap.conf dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--0e89696a--492b--494c--81fa--7e834b9f31<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>root 420 3.1 0.0 106208 1728 ? D 21:48 0:45 | \_ /bin/dd if=/dev/zero of=/dev/mapper/cinder--volumes-volume--0e89696a--492b--494c--81fa--7e834b9f31f4 count=102400 bs=1M conv=fdatasync<o:p></o:p></span></p><p class=MsoNormal>cinder 23791 0.0 0.5 377464 41968 ? S Oct24 7:46 \_ /usr/bin/python /usr/bin/cinder-volume --config-file /etc/cinder/cinder.conf --logfile /var/log/cinder/volume.log<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>iostat output :<o:p></o:p></p><p class=MsoNormal>dm-23 0.00 0.00 0.00 18408.00 0.00 71.91 8.00 503.06 28.83 0.05 100.00<o:p></o:p></p><p class=MsoNormal>dm-25 0.00 0.00 0.00 20544.00 0.00 80.25 8.00 597.24 30.56 0.05 100.10<o:p></o:p></p><p class=MsoNormal>dm-29 0.00 0.00 0.00 19232.00 0.00 75.12 8.00 531.80 27.62 0.05 100.10<o:p></o:p></p><p class=MsoNormal>dm-34 0.00 0.00 0.00 20128.00 0.00 78.62 8.00 498.10 24.92 0.05 100.00<o:p></o:p></p><p class=MsoNormal>dm-39 0.00 0.00 0.00 18355.00 0.00 71.70 8.00 534.77 28.98 0.05 100.00<o:p></o:p></p><p class=MsoNormal>dm-59 0.00 0.00 0.00 18387.00 0.00 71.82 8.00 587.79 32.10 0.05 100.00<o:p></o:p></p><p class=MsoNormal>dm-96 0.00 0.00 0.00 16480.00 0.00 64.38 8.00 467.96 27.51 0.06 100.00<o:p></o:p></p><p class=MsoNormal>dm-97 0.00 0.00 0.00 17024.00 0.00 66.50 8.00 502.25 29.21 0.06 100.00<o:p></o:p></p><p class=MsoNormal>dm-98 0.00 0.00 0.00 20704.00 0.00 80.88 8.00 655.67 31.37 0.05 100.00<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-CA>parent dm :<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>dm-0 142.00 74394.00 100.00 2812.00 1.00 302.41 213.38 156.74 52.84 0.34 100.00<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Thank you very much ,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Dave<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p></div></body></html>