As we move into the world of Software-Defined Storage it “sticks out like a sore thumb” when an array vendor only makes new software releases available on their next generation hardware. The problem with this is that even if you purchase at the very beginning of the life cycle of a product, at best you will get one round of feature enhancements, after that all software development is focused on the next generation product. This often even includes support for new drive types – again they are only supported on the latest generation hardware.
This problem is very evident when it comes to support for VMware Virtual Volumes – any array vendor that will be releasing new hardware next year is unlikely to provide support for Virtual Volumes on their currently shipping product. My view is that the industry cannot continue like this and instead they need to make sure new microcode versions and drive technologies are supported on the current shipping product and at least the previous generation – without this there is a real danger that your new storage array becomes obsolete shortly after purchase.
The good news for NetApp customers is that Clustered Data ONTAP (cDOT) meets my criteria above, so the recently announced version 8.3 will not only work on 2014 generation hardware (2500 and 8000 series), but previous generations as wells.
So what’s 8.3 all about?
- MetroCluster support – to enable continuous availability
- SnapMirror to Tape (SMTape) – simplifies and speeds up backup to tape
- Virtual Volumes support – enables native storage of VMDKs (requires vSphere 6)
- Combined SnapMirror and SnapVault – so that you only need to send the data once, rather than having separate SnapMirror and SnapVault copies
- SnapMirror and SnapVault Compression – traffic can now be optionally compressed to reduce bandwidth requirements
- Root Drive and Flash Pool Partitioning – no longer requires Root Vols and Flash Pool drives to be dedicated to a single node therefore provides better capacity utilisation
- Flash Pool enhancements – caches overwrites larger than 16K and compressed blocks, increases the usable capacity, and supports much larger pool sizes (up to 4x)
- Inline zero write detection and elimination – so host disk zeroing activity does not consume I/O or capacity
- Significant performance improvements – further multi-core, SSD random read, CIFS, replication and cloning optimisations
Migration and Administration Tools
- 7-Mode Transition Tool – now supports SAN as well as NAS
- Foreign LUN Import (Offline) – to simplify 3rd party (EMC, HDS, HP) SAN data migration
- LUN migration – whereas previously an entire volume could be non-distributively moved around the cluster it can now also be performed at the LUN level
- Disaster Recovery fail-over – to a specific point-in-time snapshot copy at the DR site for recovery from mirrored corruption
- Automated Non-disruptive Upgrade – requires just 3 commands to upgrade an entire cluster
8.3 is a milestone release for NetApp as it is the end of development for 7-Mode as 8.3 only includes the cDOT build. Overall I think NetApp are finally in a good place with cDOT and they can now put the 7-Mode platform behind them and focus on innovating.
So what would we like to see in the next version of cDOT?
- SnapLock (for retention and compliance) – the last remaining major feature to be ported over from 7-Mode
- Erasure coding – to enable rapid drive rebuilds
- Sharing of drives across controllers – we are already starting to see this with the new drive and Flash Pools partitioning features
- Detaching of the drives from the controllers – so that the failure of an HA pair within a cluster does not result in downtime
- Controller based Flash modules – in place of Root Vol drives
- Advanced QoS – to enable setting of Service Level Objectives rather than just limits
- Automated Tiering – we have flash caching, but it would be nice if we could move data between flash, SAS and SATA drives
- Integrated file archiving – to move older files to secondary storage or the cloud
- Encryption – provided by the controllers rather than drives
- MetroCluster granular fail over – so volumes or even Virtual Volumes can be “moved” between sites
- MetroCluster IP replication – either using FCIP bridges or native IP connectivity
- MetroCluster Active/Active – so volumes/LUNs can be active on both sides of the cluster
- Is NetApp Clustered Data ONTAP finally ready for primetime?
- Comparing NetApp MetroCluster with EMC VPLEX Metro Continuous Availability solutions
- What are the pros and cons of Software-Defined Storage?
- An introduction to VMware Virtual Volumes Software-Defined Storage technology