1. Block Storage Considerations for OpenStack
Wen Yu, Solutions Architect
Jay Wang, Principal Engineer

2. Top Customer Challenges Practice Solutions with Block Storage
Agenda
Top Customer Challenges
Practice Solutions with Block Storage
Ideas Sharing
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3. Top Customer Challenges
vSphere Admin
KVM/Xen
Cloud Architect
KVM
Windows
Linux/Windows
Devops
Chef/Puppet
SAN
JBOD/SAN
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4. Beginner Challenges + Practice Solution
Controller/DB as VMs
Backed by Datastore
Array based Snapshots
Controller Datastore
DB Datastore
Option 1: KVM inside ESXi
To run nested virtualization inside VMware VM (i.e., KVM nested in ESXi) – update /etc/vmware/esx.conf (vhv.enable=true) and add the following lines to the controller all-in-one VM, or VM that will run Nova (monitor.virtual_exec = “hardware”; hypervisor.cpuid.v0 = “FALSE”)
Option 2: Leverage vSphere as Hypervisor, by using Nova driver for vCenter & VMDK Cinder driver
Option 3: After getting familiarity with option 1, expand Nova compute by running KVM on physical hardware, as oppose to virtual
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5. Service Provider/Cloud Architect Challenges
Flexible, Differentiated Block Storage Offerings
Cinder
(Multi-backend)
Traffic Isolation
Multipathing
Storage Offload
Glance
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6. Multi-Cinder Reference Model
LVM
(Local JBOD)
Cost Effective
LVM
(Array Volume)
High Performance
Multipathing
Cinder Volume Driver
(Array Volume Dedicated)
Multipathing
Traffic isolation
Snapshot/Clone Offload
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7. Multi-Cinder Example: Cinder.conf
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8. Glance Tricks with Shared Storage
Boot from Volume
Snapshot offload
Rapid Clone
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9. Multipathing Options Why multipathing vSphere as hypervisor
Performance
Redundancy
vSphere as hypervisor
Port binding + SATP + PSP
LVM backed by Storage Volume
pvcreate on multipath device
Cinder Shared Storage Volume
Configure nova
Login redirection
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10. 1 2 3 4 Install device-mapper-multipath / multipath-tools
Multipathing: How-to 1
Install device-mapper-multipath / multipath-tools 2
/etc/multipath.conf
/etc/nova/nova.conf (libvirt_iscsi_use_multipath=true) 3
Attach volume to instance 4
Add additional iSCSI Connection
Set target node.session.nr_sessions
Setting up multipath (example on CentOS)
# sudo yum install device-mapper-multipath
# modify /etc/multipath.conf for your device specific configuration
modprobe dm-multipath
service multipathd start
# vi /etc/nova/nova.conf
and set "libvirt_iscsi_use_multipath=true"
# attach a volume to instance
etc]# multipath -ll
mpatha (26bda11020cb25daf6c9ce900fd3aaf17) dm-2 Nimble,Server
size=2.0G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
  `- 4:0:0:0 sdb 8:16 active ready running
# add additional iSCSI session
  |- 4:0:0:0 sdb 8:16 active ready running
  `- 5:0:0:0 sdc 8:32 active ready running
# give it a try on guest
dd if=/dev/zero of=/dev/vdb bs=4k count=100000
# check path io stat on compute node
# iostat -d 2 |egrep "Device|sdb|sdc"
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sdb              68.50         0.00               0     135424
sdc              63.00         0.00               0    
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11. Backup / Restore Swift / S3 Shared storage Backup entire volume
Compression, deduplication, encryption
Need incremental backup (changed block tracking)
Restore can take time and may be costly
Shared storage
Backup using snapshot + replication
Efficient and flexible
Replication and volume import
Multisite dev/op
Easy to restore and scale
© 2014 Nimble Storage. Proprietary and confidential. Do not distribute.