openstack team mailing list archive

[Hua ZZ Zhang <zhuadl@xxxxxxxxxx>]

+me :-)

   Swift is much like Amazon S3(Simple Storage Service), and Nova-volume is
   much like Amazon EBS (Elastic Block Store).
   Swift is used as object store of VM images in OpenStack. but Nova-volume
   is used to store persistent data of VM instances which means even the
   instance was destroyed, the volume data will still be available for
   user. for example, it can be attached to another instance instead.
   Swift data model is a kind of Container/Object and providing unlimited
   number of objects, but Nova-volume is block device (much like a hard
   drive).
   The interesting thing is that Amazon ESB could provide snapshots of
   volumes which can be persisted to Amazon S3. So the same snopshot can
   spawn as many volumes as you want.

Best Regards,

                                                                             
 Edward Zhang(张华)                    地址:北京市海淀区东北旺西路8号 中关村 
 Staff Software Engineer               软件园28号楼 环宇大厦3层 邮编：100193 
 Travel&Transportation Standards       Address: 3F Ring, Building 28         
 Emerging Technology Institute(ETI)    Zhongguancun Software Park, 8         
 IBM China Software Development Lab    Dongbeiwang West Road, Haidian        
 e-mail: zhuadl@xxxxxxxxxx             District, Beijing, P.R.C.100193       
 Notes ID: Hua ZZ Zhang/China/IBM                                            
 Tel: 86-10-82450483                                                         
                                                                             
                                                                             
                                                                             
                                                                             
                                                                             
                                                                             
                                                                             





                                                                           
             Oleg Gelbukh                                                  
             <ogelbukh@miranti                                             
             s.com>                                                     To 
             Sent by:                  Eric Luo <nextfool@xxxxxxxxx>       
             openstack-bounces                                          cc 
             +zhuadl=cn.ibm.co         openstack@xxxxxxxxxxxxxxxxxxx       
             m@lists.launchpad                                     Subject 
             .net                      Re: [Openstack] [nova-volumes]      
                                       relationship between nova-volumes   
                                       and swift?                          
             2012-04-28 15:47                                              
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Hello, Eric

Swift is actually an object store rather then volume store. It is used for
storing any types of objects as files in underlying file system. This files
can be anything, including binary images of block volumes. HTTP is used for
transporting objects to and from the store.
Nova-volume service is totally different. It allows to attach virtual block
devices to VMs by providing correct parameters for nova-compute's
'attach_volume' method. It has a number of drivers that can manage
different storage back-ends (Linux LVs, SAN virtual disks, distributed
storage systems), but all these back-ends must be able to provide a virtual
block device to VMs, which Swift is not capable of.
Primary integration point between Swift and nova-volume is a way to store
snapshots of virtual volumes to Swift store as files:
https://blueprints.launchpad.net/nova/+spec/store-snapshots-to-swift.
Status of work on this blueprint is unknown to me.

--
Best regards,
Oleg

On Sat, Apr 28, 2012 at 10:15 AM, Eric Luo <nextfool@xxxxxxxxx> wrote:
  Hello ,all
  I am a little confused about the nova-volumes service and the swift.I
  know both are about the volume store,but
  what's the relationship between them ?Can some one please explain it to
  me please :)
  Thanks!

  Eric Luo
  2012-04-28



  _______________________________________________
  Mailing list: https://launchpad.net/~openstack
  Post to     : openstack@xxxxxxxxxxxxxxxxxxx
  Unsubscribe : https://launchpad.net/~openstack
  More help   : https://help.launchpad.net/ListHelp

_______________________________________________
Mailing list: https://launchpad.net/~openstack
Post to     : openstack@xxxxxxxxxxxxxxxxxxx
Unsubscribe : https://launchpad.net/~openstack
More help   : https://help.launchpad.net/ListHelp