There's also cinder functionality called the 'generic image cache' that does this for you; see the (per-backend) config options: image_volume_cache_enabled, image_volume_cache_max_size_gb and image_volume_cache_max_count
On 20 January 2017 at 16:54, Chris Friesen <[email protected]> wrote: > On 01/20/2017 04:07 AM, Marco Marino wrote: > >> Hi, I'm trying to use cinder with lvm thin provisioning. It works well >> and I'd >> like to know if there is some reason lvm thin should be avoided in mitaka >> release. I'm trying to use with >> max_over_subscription_ratio = 1.0 >> so I don't have problems with over subscription. >> I using thin provisioning because it is fast (I think). More precisely, >> my use >> case is: >> >> - create one bootable volume. This is a long operation because cinder >> download >> the image from glance, qemu-img convert in raw format and then "dd" copy >> the >> image in the volume. >> - Create a snapshot of the bootable volume. Really fast and reliable >> because the >> original volume is not used by any vm. >> - Create a new volume from the snapshot. This is faster than create a new >> bootable volume. >> >> Is this use correct? Can I deploy in the production environment (mitaka - >> centos 7) >> Thank you >> > > For what it's worth we're using cinder with LVM thin provisioning in > production with no overprovisioning. > > What you're proposing should work, you're basically caching the vanilla > image as a cinder snapshot. > > If you wish to speed up volume deletion, you can set "volume_clear=none" > in the cinder.conf file. > > Be aware that LVM thin provisioning will see a performance penalty the > first time you write to a given disk block in a volume, because it needs to > allocate a new block, zero it out, then write the new data to it. > > Chris > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: [email protected]?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > -- -- Duncan Thomas
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