Just as NetApp dominated the older version of the SPEC SFS97_R1 NFS benchmark back in May of 2006 (and was unsurpassed in that benchmark with 1 million SFS operations per second), the time has come to once again dominate the current version, SPEC SFS2008 NFS.
Recently we have been focusing on benchmarking realistic configurations that people might actually put in their datacenters, instead of lab queens with unusable configs focused on achieving the highest result regardless of cost.
However, it seems the press doesn’t care about realistic configs (or to even understand the configs) but instead likes headline-grabbing big numbers.
So we decided to go for the best of both worlds – a headline-grabbing “big number” but also a config that would make more financial sense than the utterly crazy setups being submitted by competitors.
Without further ado, NetApp achieved over 1.5 million SPEC SFS2008 NFS operations per second with a 24-node cluster based on FAS6240 boxes running ONTAP 8 in Cluster Mode. Click here for the specific result. There are other results in the page showing different size clusters so you can get some idea of the scaling possible.
See below table for a high-level analysis (including the list pricing I could find for these specific performance-optimized configs for whatever that’s worth). The comparison is between NetApp and the nearest scale-out competitor result (one of many EMC’s recent acquisitions – Isilon, the niche, dedicated NAS box – nothing else is close enough to bother including in the comparison).
BTW – the EMC price list is publicly available from here (and other places I’m sure): http://www.emc.com/collateral/emcwsca/master-price–list.pdf
From page 422:
S200-6.9TB & 200GB SSD, 48GB RAMS200-6.9TB & 200GB SSD, 48GB RAM, 2x10GE SFP+ & 2x1G $84,061. Times 140…
Before we dive into the comparison, an important note since it seems the competition doesn’t understand how to read SPEC SFS results:
Out of 1728 450GB disks (the number includes spares and OS drives, otherwise it was 1632 disks), the usable capacity was 574TB (73% of all raw space – even more if one considers a 450GB disk never actually provides 450 real GB in base2). The exported capacity was 288TB. This doesn’t mean we tried to short-stroke or that there is a performance benefit exporting a smaller filesystem – the way NetApp writes to disk, the size of the volume you export has nothing to do with performance. Since SPEC SFS doesn’t use all the available disk space, the person doing the setup thought like a real storage admin and didn’t give it all the available space.
Lest we be accused of tuning this config or manually making sure client accesses were load-balanced and going to the optimal nodes, please understand this: 23 out of 24 client accesses were not going to the nodes owning the data and were instead happening over the cluster interconnect (which, for any scale-out architecture, is worst-case-scenario performance). Look under the “Uniform Access Rules Compliance” in the full disclosure details of the result in the SPEC website here. This means that, compared to the 2-node ONTAP 7-mode results, there is a degradation due to the cluster operating (intentionally) through non-optimal paths.
|Cost (approx. USD List)||11,800,000||6,280,000||NetApp is almost half the cost while offering much higher performance|
|SPEC SFS2008 NFS operations per second||1,112,705||1,512,784||NetApp is over 35% faster, while using potentially better RAID protection|
|Average Latency (ORT)||2.54||1.53||NetApp offers almost 40% better average latency without using costly SSDs, and is usable for challenging random workloads like DBs, VMs etc.|
|Space (TB)||864 (out of which 128889GB was used in the test)||574 (out of which 176176GB was used in the test)||Isilon offers about 50% more usable space (coming from a lot more drives, 28% more raw space and potentially less RAID protection – N+2 results from Isilon would be different)|
|$/SPEC SFS2008 NFS operation||10.6||4.15||Netapp is less than half the cost per SPEC SFS2008 NFS operation|
|$/TB||13,657||10,940||NetApp is about 20% less expensive than EMC per usable TB|
|RAID||Per-file protection. Files < 128K are at least mirrored. Files over 128K are at a 13+1 level protection in this specific test.||RAID-DP||Ask EMC what 13+1 protection means in an Isilon cluster (I believe 1 node can be completely gone but what about simultaneous drive failures that contain the sameprotected file?)NetApp RAID-DP is mathematically analogous to RAID6 and has a parity drive penalty of 2 drives every 16-20 drives.|
|Boxes needed to accomplish result||140 nodes, 3,360 drives (incl. 25TB of SSDs for cache), 1,120 CPU cores, 6.7TB RAM.||24 unified controllers, 1,728 drives, 12.2TB Flash Cache, 192 CPU cores, 1.2TB RAM.||NetApp is far more powerful per node, and achieves higher performance with a lotless drives, CPUs, RAM and cache.In addition, NetApp can be used for all protocols (FC, iSCSI, NFS, CIFS) and all connectivity methods (FC 4/8Gb, Ethernet 1/10Gb, FCoE).|
Notice the response time charts:
NetApp exhibits traditional storage system behavior – latency is very low initially and gradually gets higher the more the box is pushed, as one would expect. Isilon on the other hand starts out slow and gets faster as more metadata gets cached, until the controllers run out of steam (SPEC SFS is very heavy in NAS metadata ops, and should not be compared to heavy-duty block benchmarks like SPC-1).
This is one of the reasons an Isilon cluster is not really applicable for low-latency DB-type apps, or low-latency VMs. It is a great architecture designed to provide high sequential speeds for large files over NAS protocols, and is not a general-purpose storage system. Kudos to the Isilon guys for even getting the great SPEC result in the first place, given that this isn’t what the box is designed to do (the extreme Isilon configuration needed to run the benchmark is testament to that). The better application for Isilon would be capacity-optimized configs (which is what the system is designed for to begin with).
Some important points:
- First and foremost, the cluster-mode ONTAP architecture now supports all protocols, it is the only unified scale-out architecture available. Any competitors playing in that space only have NAS or SAN offerings but not both in a single architecture.
- We didn’t even test with the even faster 6280 box and extra cache (that one can take 8TB cache per node). The result is not the fastest a NetApp cluster can go 🙂 With 6280s it would be a healthy percentage faster, but we had a bunch of the 6240s in the lab so it was easier to test them, plus they’re a more common and less expensive box, making for a more realistic result.
- ONTAP in cluster-mode is a general-purpose storage OS, and can be used to run Exchange, SQL, Oracle, DB2, VMs, etc. etc. Most other scale-out architectures are simply not suitable for low-latency workloads like DBs and VMs and are instead geared towards high NAS throughput for large files (IBRIX, SONAS, Isilon to name a few – all great at what they do best).
- ONTAP in cluster mode is, indeed, a single scale-out cluster and administered as such. It should not be compared to block boxes with NAS gateways in front of them like VNX, HDS + Bluearc, etc.
- In ONTAP cluster mode, workloads and virtual interfaces can move around the cluster non-disruptively, regardless of protocol (FC, iSCSI, NFS and yes, even CIFS can move around non-disruptively assuming you have clients that can talk SMB 2.1 and above).
- In ONTAP cluster mode, any data can be accessed from any node in the cluster – again, impossible with non-unified gateway solutions like VNX that have individual NAS servers in front of block storage, with zero awareness between the NAS heads aside from failover.
- ONTAP cluster mode can allow certain cool things like upgrading storage controllers from one model to another completely non-disruptively, most other storage systems need some kind of outage to do this. All we do is add the new boxes to the existing cluster 🙂
- ONTAP cluster mode supports all the traditional NetApp storage efficiency and protection features: RAID-DP, replication, deduplication, compression, snaps, clones, thin provisioning. Again, the goal is to provide a scale-out general-purpose storage system, not a niche box for only a specific market segment. It even supports virtualizing your existing storage.
- There was a single namespace for the NFS data. Granted, not the same architecture as a single filesystem from some competitors.
- Last but not least – no “special” NetApp boxes are needed to run Cluster Mode. In contrast to other vendors selling a completely separate scale-out architecture (different hardware and software and management), normal NetApp systems can enter a scale-out cluster as long as they have enough connectivity for the cluster network and can run ONTAP 8. This ensures investment protection for the customer plus it’s easier for NetApp since we don’t have umpteen hardware and software architectures to develop for and support 🙂
- Since people have been asking: The SFS benchmark generates about 120MB per operation. The slower you go, the less space you will use on the disks, regardless of how many disks you have. This creates some imbalance in large configs (for example, only about 128TB of the 864TB available was used on Isilon).
Just remember – in order to do what ONTAP in Cluster Mode does, how many different architectures would other vendors be proposing?
- Scale-out SAN
- Scale-out NAS
- Replication appliances
- Dedupe appliances
- All kinds of management software
How many people would it take to keep it all running? And patched? And how many firmware inter-dependencies would there be?
And what if you didn’t need, say, scale-out SAN to begin with, but some time after buying traditional SAN realized you needed scale-out? Would your current storage vendor tell you you needed, in addition to your existing SAN platform, that other one that can do scale-out? That’s completely different than the one you bought? And that you can’t re-use any of your existing stuff as part of the scale-out box, regardless of how high-end your existing SAN is?
How would that make you feel?
Always plan for the future…
PS: Made some small edits in the RAID parts and also added the official EMC pricelist link.