[openstack-dev] Proposal for dd disk i/o performance blueprint of cinder.
chris.friesen at windriver.com
Wed Jan 15 22:39:45 UTC 2014
On 12/26/2013 01:56 AM, cosmos cosmos wrote:
> My name is Rucia for Samsung SDS.
> I had in truouble in volume deleting.
> I am developing for supporting big data storage such as hadoop in lvm.
> it use as a full disk io for deleting of cinder lvm volume because of dd
> the high disk I/O affects the other hadoop instance on same host.
> If using dd for deleting the volume, it takes too much time for
> deleting of cinder lvm volume because of dd.
> Cinder volume is 200GB for supporting hadoop master data.
> When i delete cinder volume in using 'dd if=/dev/zero of $cinder-volume
> count=1000000 bs=1M' it takes about 30 minutes.
While I think your ionice proposal makes some sense, I think it would be
better to avoid the cost of the volume wipe on deletion in the first place.
I read a proposal about using thinly-provisioned logical volumes as a
way around the cost of wiping the disks, since they zero-fill on demand
rather than incur the cost at deletion time.
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