Monday, July 27, 2015


I spent some time putting information together on SAN on CDOT.  
-          Basic Architecture
o   CDOT uses NPIV to virtualize WWPNs.  This means any node can take traffic for any vserver, and ALUA optimizes the paths.
o   When zoning, utilize these vWWPNs and not the physical WWPNs.
o   Each SVM gets its own IQN (iSCSI) or WWNN (FC).
o   8-node cluster limit today
o   LUNs can be moved to new volumes non-disruptively inside a cluster
o   Limits
§  CDOT 8.2: 8,192 LUNS per node | 49,152 LUNS per cluster | 2,048 iSCSI sessions per node
§  CDOT 8.3: 12,288 LUNS per node | 98,304 LUNS per cluster | 8,192 iSCSI sessions per node
§  Linux host (8.2): 2,048 devices (# LUNS * # paths) | 16TB LUNs
§  Windows (8.2): 255 LUNs per host, 2TB LUNs (MBR) or 16TB (GPT)
o   FAS80X0 support 4-port 8Gb cards or 2-port 16Gb cards.
-          Useful commands:
o   Network interface show (will show FCP lifs)
o   Fcp show
o   Igroup show
o   Lun show
o   system node run -node cluster1-01 fcp topology show
o   Useful SAN Setup how-to (8.1 but very applicable):
-          Foreign LUN Import: 8.3 feature, no license required.  8.3.1 enables the online import using redirect.  Cutover happens first: pause IO to foreign SAN, present LUN to NetApp.  Foreign LUN shows up as a disk in ONTAP (think V-series) and then map this disk to the original host to serve the data.  Bring everything online, data is copied to NetApp while serving data.  Once it’s all moved, shut down foreign SAN. 

You can find the 8.2 SAN config guide here:
And 8.2.1 SAN Config Guide updates:
8.3 SAN config Guide:

Friday, July 24, 2015

NetApp IT: Why Clustered Data ONTAP is the Key to Unlocking the Hybrid Cloud

"Business has changed for NetApp IT with the adoption of the hybrid cloud model. The key to our strategy is NetApp® clustered Data ONTAP®, the foundation for our on-premises storage environment and an integral part of our hybrid cloud model. Clustered Data ONTAP enables our hybrid cloud model because of its ability to enhance the scale-out architecture and non-disruptive operations of clustered Data ONTAP."

Monday, July 20, 2015

Blog Views

My blog just crossed 60,000 views.  How cool is that?  Sure, that's small potatoes today with billions of people online, and I'm sure a blog with cats or bikinis would do that many views in a day...but in the absence of clickbait on my site, you can be assured that everyone reaching my blog is an engineer of some kind, looking for technical answers.

It's a very small world of data storage engineers and they make huge purchasing decisions.  That so many in this small market are landing on my blog and learning NetApp's technology here is pretty awesome.

CDOT Tip: PerfStat GUI

Running perfstat via command line or linux server can be inconvenient.  The good news is you can run perfstat via the GUI for 7-mode or CDOT on a Windows system to quickly set up, gather data, and upload it to NetApp!

Once you’ve gathered the data, upload to the case via   This uploads the data into the right system, crunches the numbers, and the support engineer is notified.  Attaching the perfstat to the case will transfer the file but not upload it into our performance system, and unfortunately some TSE’s won’t notice the file attached to the case.   There are instructions here:

Wednesday, July 15, 2015

Always On Dedupe

We're finding more and more clients with transient data who want to dedupe all the time.  With more powerful systems and especially the advent of flash, you can set dedupe to run all the time with little to no performance impact.  Here's a primer:

You can set it to always on like this:

Create a schedule object:
cluster:>> job schedule cron create –name per_minute –dayofweek * –hour * –minute 1

Create a dedupe policy linked to that schedule:
cluster:>> volume efficiency policy create –vserver -policy “Always_On_Dedupe” –type schedule –schedule per_minute –qos-policy background –enabled true

Assign that dedupe policy to your volume:

cluster::> volume efficiency on -volume -vserver -qos-policy Always_On_Dedupe

Those commands might be a bit off, I’m writing free-hand here.  It would be easier to use system manager to do it via GUI:

And here are some of the published results:

Design, testing, and results document:

Command Reference Link:

Monday, July 13, 2015

CDOT Tip #10: CDOT 8.3.1 Features

8.3.1 has a big payload for a minor release and will be out early fall. Here are the Top 10 you care about!

  1. AFF Performance improvements: Reads are 600-900us faster over 8.3.1 from re-engineering the IO path for SSD’s.  
  2. All Flash FAS Configuration
    1. Inline compression always-on by default, with same performance as 8.3 without compression
    2. Zero block detection and dedupe by default
  3. SVM DR (Storage Virtual Machine Disaster Recovery)
    1. This replicates an entire vserver from one cluster to another, including exports, IPs, etc, allow for easy failover to DR site.  Think SnapMirror for vservers!
    2. Automated change management, automated setup and provisioning. 
    3. Retains CIFS shares, NFS exports, permissions, names, data, network config, certificates, QOS policies, and much more.
  4. Additional CDOT MetroCluster configurations, including AFF, FlashPool, and 200km stretch
  5. Cluster Peering Enhancements: This enables CDOT to snapmirror or SVM DR to multiple other clusters in multiple IPspaces.
  6. Encryption for Cloud ONTAP, a CDOT virtual instance available in AWS or Azure.
  7. Foreign LUN Import enhancement: reduces downtime required to migrate LUNs onto NetApp by mirroring dataset and redirecting traffic.
  8. Upgrades to built-in system manager, including AFF-specific changes, enabling ONTAP upgrades from the GUI, and easier network config.
  9. Usability enhancements:
    1. Enhancements for audit log management
    2. Support of LDAP and NIS user authentication for cluster access 
    3. Support for the banner and Message of the Day (MOTD)
    4. New FlashPool caching policies
    5. Automated Workload Analyzer (AWA) volume-level reporting to predict the impact of larger FlashPool/FlashCache.
  10. Protocol enhancements:
    1. Support for dynamic DNS
    2. Support for Windows NFSv3 clients
    3. Support for SMB encryption for data transfers over SMB
    4. Support for configuring a guest UNIX user
    5. Support for mapping the administrators group to root
    6. Enhancements to SQL Server and Hyper-V over SMB solutions

Read more at 8.3.1 release notes:

CDOT Tip #9: Commands

You can find the command document for CDOT 8.3 here:

Also, CDOT 8.3.1RC1 is out, with 8.3.1 expected early this fall.  More to come on this soon!