Software Defined Storage. Reality or BS?

Transcription

1 Software Defined Storage Reality or BS?

2 Defining Software Defined Storage We must resist software defined washing My Criteria: Must run on x86 server hardware No custom ASICs NVRAM allowed Can be sold as software or Appliance Wrapped in tin

3 Software Defined Storage is not New Novell NetWare turned PC AT into file server Software defined NAS I wrote How to Build Your Own iscsi Array in 2006 Faster x86 processors are driving SDS In performance In scale In functionality

4 Software Defined Storage Taxonomy Storage SoftwareDefinus OldSchoolus Runs on standard server Publishes block or file Storage SoftwareDefinus Virtualum The classic VSA Like OldSchoolus but runs in a VM Storage SoftwareDefinus Virtucalis Scaleoutus Also known as ServerSAN Pools storage across hypervisor hosts

5 Old School SDS Software runs under Windows or Linux Publish storage as iscsi or file Standard RAID Could require HW controller Synchronous replication with failover

6 Selected Classic SDS FreeNAS/OpenNAS Etc. Open source ZFS based NAS/iSCSI Include SSD caching Open-E DSS Open source assemblage w/support NexentaStor Commercial ZFS Supports shared storage StarWind Windows based iscsi target w/ssd caching

7 Wrap in Tin? Most next generation storage arrays are SDS Nimble Storage Tintri Why? Qualification and support Margins Channel issues Customer preferences Fusion-IO IOcontrol (Nexgen) Tegile

8 Or Virtualize The Servers Creating a Virtual Storage Appliance (VSA) VSAs great solution for ROBO, SMB Local storage, may require RAID controller Publish as iscsi or NFS Example: Stormagic Basic iscsi VSA 2 nodes $2500

9 Another Taxonomy View

10 Why Converge Storage and Compute? Makes corporate data center like cloud A good or bad thing Storage array slot and SAN costs Generally higher than the disk drive that plugs in Server slots are already paid for Political, management issues Moves storage to server team

11 Enter The ServerSAN Scale-out where storage controllers are fail-over clusters Storage across n hypervisor hosts to form one pool Maximum cluster sizes 8-32 nodes VSA or kernel process Use SSD as cache or tier Can be software or hyperconvirged servers

12 ServerSAN architecture differentiators Data protection model Per node RAID? N-way replication Network RAID? Flash usage: Write through or write back cache SubLUN tiering Prioritization/Storage QoS Data locality Data reduction Snapshots and cloning

13 Hyperconvirged Systems Nutanix Derived from Google File System 4 nodes/block Multi-hypervisor Storage for cluster only Simplivity Dedupe and backup to the cloud Storage available to other servers 2u Servers Both have compute and storage heavy models Pivot3 for VDI only ScaleComputing KVM based for SMBs Vmware EVO:RAIL

14 Vmware s VSAN SSD as read/write cache N-way replication (no local RAID) Default 2 copies, requires 3 nodes 3 copies requires 5 nodes (my recommendation) Scales to 32 nodes Runs directly in hypervisor kernel Storage only available to cluster members Relies on vsphere snapshots, replication License $2495/CPU or $50/VDI image

15 Software Only ServerSANs HP StoreVirtual (Lefthand) Sub-LUN tiering for SSDs iscsi system scales to 10 nodes Data Protection Per Node RAID 2-4 way replication or network RAID 5 or 6 Maxta Storage Platform Data deduplication and compression Metadata based snapshots Data integrity via hashes/scrubbing Data locality

16 More Software ServerSANs EMC ScaleIO Extreme scale-out to 100s of nodes Multi-hypervisor Kernel modules for KVM, XEN, Hyper-V Multiple storage pools Some QoS Metadata snaps and clones Sanbolic Melio Evolved from clustered file system Perhaps the most mature

17 ServerSANs and Server Form Factors Mainstream 1u servers offer limited storage 2u servers the sweet spot 6-24 drive bays for both SSDs and HDDs Slots for 10Gbps Ethernet and PCIe SSDs Blades unsuitable 1-2 SFF disk bays Mezzanine PCIe SSDs generally >$8000 High density servers can work

18 Challenges to SDS Purchasing politics and budgets Everyone likes to point at where their money went, especially storage guys So who s budget Easier if savings big enough that storage+compute now costs storage or compute VDI can be camel s nose because it needs dedicated infrastructure anyway

19 Operational Challenges Storage guys are paranoid for good reason Storage is persistent and so are storage mistakes Server guys are less paranoid VSAN with default 2 copies VMware admin takes 1 server offline The 1 disk with data fails.

20 ServerSAN vs Dedicated Storage VMware s benchmark config 32 nodes 400GB SSD and 7 1TB drives each VSAN cost ~$11,000/server for 2.3TB useable (73TB total) Best of breed dedicated storage Tintri T TB usable $160,000 ~100,000 real IOPS Per VM snaps and replication

21 Questions and Contact Contact on Twitter