1. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Practical High Availability NAS
Cost-effective, non-stop disk access
for clustered file shares

2. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
 Problem: Cost to achieve necessary redundancy &
speed can be prohibitive
 Alternative: Extend DataCore storage virtualization
servers into high-availability (HA) NAS role
► Couple SANsymphony-V storage hypervisor features
with Windows Server 2008 R2 NFS/SMB file sharing &
clustering capabilities in Enterprise Edition
► No additional software required
► Combine into unified HA storage solution (SAN/NAS)
Availability & performance of file shares
has become mission critical
2

3. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Compelling value
FEATURE
 Clustered file shares
 Synchronous mirroring
 w/ automatic
non-disruptive failover
 Redundant NAS servers
up to 100 km apart
 Thin provisioning
 Cache acceleration
 Remote replication
BENEFIT
• Business continuity & HA
• Avoid storage-related
downtime
• Minimize impact of
equipment & facility problems
• Maximize space utilization
• Faster performance
• Extend protection for disaster
avoidance & recovery

4. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Windows NAS (a.k.a. File Server)
4
filestore
/home/home
Host Host
NFS / SMB
NAS

5. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
NAS server outage affects everyone
5
filestore
/home/home
Host Host
NFS / SMB
NAS

6. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Clustered servers help, but …
Failover
Clustering
/home/home
Host Host
NFS / SMBNFS / SMB
Server 1 Server 2
NAS
Shared disk access remains a single point of failure!
witnessfilestore
Shared disks

7. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Solution: Full redundancy
Failover
Clustering
/home/home
Host Host
NFS / SMBNFS / SMB
Server 1 Server 2
NAS
witnessfilestore witnessfilestore
witnessfilestore
Room 1 Room 2
Shared “virtual” disks
Mirrored copiesPrimary disks

8. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Non-stop, high-availability NAS
/home
witness
filestore
SAN
witness
filestore
CacheCache
/home
NFS / SMBNFS / SMB
Host Host
Failover
Clustering
Synchronous
Mirroring
NAS
Room 1 Room 2
Mirrored copiesPrimary disks

9. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Non-disruptive failover
/home
witness
filestore
SAN
witness
filestore
CacheCache
/home
NFS / SMB
Host Host
Failover
Clustering
Synchronous
Mirroring
Room 1 Room 2
NFS / SMB
NAS
Mirrored copiesPrimary disks

10. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Automatic failback
/home
witness
filestore
SAN
witness
filestore
CacheCache
/home
NFS / SMBNFS / SMB
Host Host
Failover
Clustering
Synchronous
Mirroring
NAS
Room 1 Room 2
Mirrored copiesPrimary disks

11. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Plus I/O acceleration
disk drives
Disk Drive 4000 – 6000
DataCore L1 Cache <20
Array L2 Cache 250 – 300
Avg. Response (µS)
High-Speed
Level 1 Caching
CPU
Up to 1 TB RAM
cache per node
CPU CPU
CPU
11
Virtual
Disks
Output
from Cache
Poll for
Input
Write
Coalesce
Pre-fetch

12. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Works for virtual machines (VMs) too
12
Virtual iSCSI
SAN
witness filestore
Hyper-V
VM
Virtual iSCSI
SAN
witnessfilestore
Hyper-V
VM
Failover
Clustering
Disk
Drives
D2 D1’
Disk
Drives
D2D1’
CacheCache
/home/home
NFS / SMBNFS / SMB
iSCSI InitiatoriSCSI Initiator
Synchronous
Mirroring
NAS
AppApp
Room 1 Room 2
App
VM
App
VM
Mirrored copiesPrimary disks

13. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
NAS failover with Hyper-V
13
Virtual iSCSI
SAN
witness filestore
Hyper-V
Virtual iSCSI
SAN
witnessfilestore
Hyper-V
VM
Failover
Clustering
Disk
Drives
D2 D1’
Disk
Drives
D2D1’
CacheCache
/home/home
NFS / SMB
iSCSI Initiator
Synchronous
Mirroring
NAS
AppApp
Room 1 Room 2
App
VM
App
VM
VM
NFS / SMB
iSCSI Initiator
Mirrored copiesPrimary disks

14. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Co-resident HA SAN/NAS:
Compact clustered servers solution
/home
Virtual Disks
Disk
Drives witness
filestore
D2 D1’
Initiator
Disks
SAN
Virtual Disks
Disk
Driveswitness
filestore
D2D1’
Disks
SAN
CacheCache
/home
NFS / SMBNFS / SMB
Host Host
TargetTargetInitiator
iSCSIiSCSI
Failover
Clustering
Synchronous
Mirroring
NAS

15. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
SAN failover
Disk
Drives
D1’
Disk
Drives
D2D1’
Virtual Disk
CacheCache
Synchronous
Mirroring
Host
Alternate Path
MPIO
Preferred Path
D2
Virtual Disk (mirror)

16. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Expandable to separate NAS & SAN servers
16
witness filestorewitnessfilestore
Failover
Clustering
Disk
Drives
D2 D1’
Disk
Drives
D2D1’
CacheCache
/home/home
Host Host
NFS / SMBNFS / SMB
Synchronous
Mirroring
Server 1 (NAS) Server 2 (NAS)
Server 3 (SAN) Server 4 (SAN)
NAS

17. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
Implementation guidelines
 DataCore resides on
parent partition
 Virtualize & cache
data drives
 Enable thin provisioning
 Place NAS servers in
different rooms
► Stretch distance
between them up to
100 km
 Synchronously mirror
across nodes

18. Copyright © 2012 DataCore Software Corp. – All Rights Reserved.
www.datacore.com