“ Enterprise class storage for everyone ”

ZFS Acceleration of Virtualised Environments

Andy Bennett

Director Sales Engineering EMEA

July 14, 2010Nexenta Systems Confidential

What is NexentaStor?

Unified storage: block and file

Leading OpenStorage solution

Runs on industry standard hardware

Offers unmatched enterprisefeatures at 70-80% savings:

•End to end data integrity

•Unlimited file size & snaps

•Synchronous and ZFS replication

Superior storage for virtualized

environments

Achieves enterprise class functionality at 75% savings 2

3

VM Sprawl – Storage Nightmare

Typical single Server

Virtual Environment of 20 Server 4 Disk VM’s

THE MORE YOU GROW YOUR VM INFRASTRUCTURE THE WORSE THE I/O PROBLEM GETS !!!!

20 x 720 IOPS Completely Random I/O Workload

Mixed I/O Workload2-6 Traditional SAS / SATA Disks per server Single disk 70-180 IOPS

Even previously Sequential workloads are now random to central storage

14400 + IOPS

4

VDI Workloads Even Worse

Typical Windows VDI Workload

VDI Deployments in the 100 – 1000’s of desktops

RANDOM WRITE WORKLOAD A HARD DISKS WORSE NIGHTMARE

500 x 35 IOPS Completely Random I/O Write Biased Workload

Up to 85% Write workloads – BASED ON RECENT TESTINGTesting shows heavily write biased in VDI environmentsSingle VDI Desktop 20-35 IOPS

Even previously Sequential workloads are now random to central storage

17,500 + IOPS

5

ZFS Caches

Level 1 Read / Write Cache – THE ARCPrimary Filesystem cacheDynamically grows and shrinks with workloadAdaptive in natureCaches all async writes and streams sequentially to backend storageAppliance wide cache for all storage pools

Level 2 Read Cache – The L2ARC

Secondary cache stores items evicted from the ARC

Adaptive in nature

All data is non resilient also stored on disk

Nonvolatile RAM card / SSD

Assigned per storage pool

Level 2 Write Cache – ZFS Intent log (ZIL)

Stores small (<32k) sync writes in high speed persistent storage

Flushes to disk backend periodically – sequential write stream

Assigned per storage pool

6

SSD’s - Why use them

• Flash sits between DRAM and Disk in terms of latency and costs

• DRAM is nanoseconds Flash is microseconds per op , Spinning Disk is milliseconds

• Flash is tens of dollars per GB whereas RAM is hundreds of dollars per GB

• For random-read workloads Flash + 7200 rpm drives can yield up to 5x performance of 15K drives at ¼ the cost

• Up to 40,000 Small File Random Write IOPS per SSD • Up to 80,000 Read IOPS per SSD• SSD’s shipping in up to 800GB MLC capacity• SLC and MLC devices available

7October 20, 2010

Hybrid Storage Pool

VA Technologies

APPLICATION

ZFS

L2ARC Disk PoolZIL

SSD SAS / SATA

8

WRITE CACHE – The ZIL

• All incoming synchronous writes committed to write optimised SSD

• Up to 40,000 Random Write IOPS per SSD• Massively Improves I/O response for sync

writes – NFS / Database especially• Turns random write workload into sequential

write stream to backend disk• Can allow 7200 rpm disk systems to

outperform traditional 15K subsystems• Only a small device < 16GB Required

9

READ CACHE – The L2ARC

ARC

• Data soon to be evicted from the ARC is added to a queue to be sent to cache L2ARC SSD

✆ Another thread sends queue to cache SSD✆ Data is copied to the cache SSD with a throttle

to limit bandwidth consumption✆ Under heavy memory pressure, not all evictions

from the ARC will arrive in the cache SSD✆ Content considered volatile as also stored on

disk• Perfect use for high capacity MLC SSD

✆ Significantly improves read latency✆ Inexpensive compared to adding DRAM✆ Up to 80,000 IOPS per SSD✆ Cache warms up over time✆ Performance scaleable – Add more SSD’s

data soon to be evicted

cachevdev

10

Snapshots and Clones

• Snapshots – a point-in-time window into the dataset (block or file) – THEY ARE READ ONLY

• Clones are READ - WRITE and based upon a snapshot• Computationally free, because of Copy on Write architecture• Very handy feature for VM’s

✆ Almost instant creation of a VM using cloned templates✆ Master template will live in the ARC or L2ARC✆ Ultra Space efficient✆ Combine with dedupe and compression for space

efficient use of storage✆ Means pure SSD only pools can be used for VM’s

11

VMDC Integration

• Single management interface for VM Infrastructures• Leverages ZFS snapshot and clone features• Integrates with standard NexentaStor features

✆ Auto-snap snapshot service• Relocate VMs between virtual hosts• Relocate VMs between NexentaStor appliances• Only Platform to support multiple virtual hosts from multiple

vendors simultaneously✆ VMware ESX 3.5 & 4.x✆ Citrix Xen 5.x✆ Microsoft Hyper-V (RSN)

“ Enterprise Class Storage for Everyone”

Thank YouSee NexentaStor in action

with VA Technologies on stand 828