Tag Archives: flare

Compression better than Dedup? NetApp Confirms!

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The more I talk with customers, the more I find that the technical details of how something works is much less important than the business outcome it achieves.  When it comes to storage, most customers just want a device that will provide the capacity and performance they need, at a price they can afford–and it better not be too complicated.  Pretty much any vendor trying to sell something will attempt to make their solution fit your needs even if they really don’t have the right products.  It’s a fact of life, sell what you have.  Along these lines, there has been a lot of back and forth between vendors about dedup vs. compression technology and which one solves customer problems best.

After snapshots and thin provisioning, data reduction technology in storage arrays has become a big focus in storage efficiency lately; and there are two primary methods of data reduction — compression and deduplication.

While EMC has been marketing compression technology for block and file data in Celerra, Unified, and Clariion storage systems, NetApp has been marketing deduplication as the technology of choice for block and file storage savings.  But which one is the best choice?  The short answer is.. it depends.  Some data types benefit most from deduplication while others get better savings with compression.

Currently, EMC supports file compression on all EMC Celerra NS20, 40, 80, 120, 480, 960, VG2, and VG8 systems running DART 5.6.47.x+ and block compression on all CX4 based arrays running FLARE30.x+.  In all cases, compression is enabled on a volume/LUN level with a simple check box and processing can be paused, resumed, and disabled completely, uncompressing the data if desired.  Data is compressed out-of-band and has no impact on writes, with minimal overhead on reads.  Any or all LUN(s) and/or Filesystem(s) can be compressed if desired even if they existed prior to upgrading the array to newer code levels.

With the release of OnTap 8.0.1, NetApp has added support for in-line compression within their FAS arrays.  It is enabled per-FlexVol and as far as I have been able to determine, cannot be disabled later (I’m sure Vaughn or another NetApp representative will correct me if I’m wrong here.)  Compression requires 64-bit aggregates which are new in OnTap 8, so FlexVols that existed prior to an upgrade to 8.x cannot be compressed without a data migration which could be disruptive.  Since compression is inline, it creates overhead in the FAS controller and could impact performance of reads and writes to the data.

Vaughn Stewart, of NetApp, expertly blogged today about the new compression feature, including some of the caveats involved, and to me the most interesting part of the post was the following graphic he included showing the space savings of compression vs. dedup for various data types.

Image Credit: Vaughn Stewart, NetApp

The first thing that struck me was how much better compression performed over deduplication for all but one data type (Virtualization will usually fare well because in a typical environment there are many VMs with the same operating system files).  In fact, according to NetApp, deduplication achieves very little savings, if any, for the majority of the data types here.
 
The light green bar indicates savings with both dedupe AND compression enabled on the same dataset.  In 5 out of 9 cases, dedup adds ZERO savings over compression alone.  I can’t help but wonder why anyone would enable dedup on those data types if they already had compression, since both features use storage array CPU resources to find and compress or dedup data.  I am aware that in some cases, dedup can improve performance on NetApp systems due to dedup-aware cache, but I also believe that any performance gain is directly related to the amount of duplication in the data.  Using this chart, virtualization is really the only place where dedup seems particularly effective and hence the only place where real performance gains would likely present themselves.
 
The challenge for NetApp customers will be getting their data into a configuration that supports compression due to the 64-bit aggregate requirement, lack of an easy and non-disruptive LUN migration feature (DataMotion appears to only support iSCSI and NFS and requires several additional licenses), and no way to convert an aggregate from 32-bit to 64-bit.  Once compression has been enabled, if there is truly no way to disable it, any resulting performance impact will be very difficult to rectify.
 
On the other hand, any EMC customer with current maintenance can upgrade their NS or CX4 array to newer versions of DART or FLARE, and compression can be enabled on any existing data after the fact.  If performance becomes an issue for a particular dataset once compressed, the data can be uncompressed later.  Both operations are completely non-disruptive and run in the background.  While block compression only works on LUNs in a virtual pool, as opposed to a traditional RAID group, enabling compression on a normal LUN will automatically migrate the LUN into a virtual pool, perform zero-page reclaim, followed by compression, and the entire process is completely non-disruptive to the application.  Oh, and compressed data can still be tiered with FASTVP across SSD, FC, and SATA disk and/or benefit from up to 2TB of FASTCache.
 
I admit that there is a place for deduplication as well as compression in reducing the footprint of customer data.  However, based on what I’ve seen in my career as an IT professional, and with my customers in my current role at EMC, there are more use cases for compression than there are for deduplication when it comes to primary data, whether SAN or NAS.  Either way, if I was using a new technology for the first time on a particular data set, whether compression or deduplication, I would definitely want a backout plan in case the drawbacks outweight the benefits.

Simplify Storage Management Today, Risk Free, and Free of Charge

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While my peers have been blogging about the new CLARiiON and Celerra releases, both of which provide significant enhancements to the EMC CX4-based Unified platforms you already own, I thought I’d shift gears just a tad…

What if you are a Clariion CX/CX3 customer, or a CX4 customer who isn’t ready to upgrade to the newly released FLARE30 code, but want to simplify management of your storage environment, get better reporting, dashboards, wizards, etc.  Well, you are in luck.

Just as with previous versions of Navisphere and FLARE, EMC offers off-array versions of Clariion management agents, servers, and GUIs.  As of yesterday, that includes off-array versions of Unisphere.  If you are a current customer of Clariion, you can login to PowerLink and download the Unisphere off-array software and build a management station.  After installation, you can manage your existing Clariion CX/CX3/CX4 hardware without upgrading the FLARE code.  As you upgrade your CX4 systems to FLARE30, new features will be enabled in Unisphere, and as you upgrade your Celerra NS systems to DART6, they can be added to the Clariion management domain and managed from the very same Unisphere instance.  How’s that for easy and convenient?

But what do you get by using Unisphere to manage your non-FLARE30 systems?  Unfortunately, you won’t be able to take advantage of FASTCache, FAST, Compression, and other features that are only available in FLARE 30, but there are some advantages..

First and foremost, Unisphere completely dumps the Navisphere tree-based management view and replaces it with end-result based tasks.  So instead of creating several objects to provision raid groups and LUNs, then present to a host, you just run the “Allocate” wizard and select the array, disks/raid group/pool, LUN size, hosts, etc and commit.

Second, upon launching Unisphere and logging in, you are immediately presented with dashboard views showing the amount of used/available storage, and active alerts, all customizable, so you can see the state of your entire CLARiiON storage environment “at-a-glance”.

To install Unisphere today, login to Powerlink, browse to “Support > Software Downloads and Licensing > Downloads T-Z > Unisphere Server Software” and download “EMC Unisphere Server” and “EMC Unisphere Client”.  Install them both to your Windows system and fire it up.  If you have Navisphere off-array software already installed, Unisphere will upgrade the existing installation for you.  You will also want to download and install Unisphere Service Manager (USM), also from Powerlink at “Support > Software Downloads and Licensing > Downloads T-Z > Unisphere Service Manager (USM).”  USM will provide various support and service related tools including active technical advisories for your storage arrays.

Begin using Unisphere today and you get some immediate benefits, plus you will be ready to take advantage of new features enabled with FLARE30 (FAST, FASTCache, Compression, etc) as well as managing NAS across all of your Celerra systems once they are upgraded to DART 6.  As a bonus, you’ll have a chance to get familiar with Unisphere before a future FLARE upgrade or new EMC Unified purchase forces you to learn it.

And did I mention you don’t have to buy anything or introduce risk with a firmware upgrade?

EMC CLARiiON and Celerra Updates – Defining Unified Storage

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This past week, during EMC World 2010 in Boston, EMC made several announcements of updates to the Celerra and CLARiiON midrange platforms.  Some of the most impressive were new capabilities coming to CLARiiON FLARE in just a couple short months.  Major updates to Celerra DART will coincide with the FLARE updates and if you are already running CLARiiON CX4 hardware, or are evaluating CX4 (or Celerra), you will want to check these new features out.  They will be available to existing CX4(120,240,480,960)/NS(120,480,960) systems as part of a software update.

Here’s a list of key changes in FLARE 30:

  • Unified management for midrange storage platforms including CLARiiON and Celerra today, plus RecoverPoint, Replication Manager and more in the future.  This is a true single pane of glass for monitoring AND managing SAN, NAS, and data protection and it’s built in to the platform.  “EMC Unisphere” replaces Navisphere Manager and Celerra Manager and supports multiple storage systems simultaneously in a single window. (Video Demo)
  • Extremely large cache (ie: FASTCache) – Up to 2TB of additional read/write cache in CLARiiON using SSDs (Video Demo)
  • Block level Fully Automated Storage Tiering (ie: sub-LUN FAST) – Fully automated assignment of data across multiple disk types
  • Block Level Compression – Compress LUNs in the CLARiiON to reduce disk space requirements
  • VAAI Support – Integrate with vSphere ESX for improved performance

These features are in addition to existing features like:

  • Seamless and non-disruptive mobility of LUNs within a storage array – (via Virtual LUNs)
  • Non-Disruptive Data Migration – (via PowerPath Migration Enabler)
  • VMWare Aware Storage Management – (Navisphere, Unisphere, and vSphere Plugins giving complete visibility  and self-service provisioning for VMWare admins (Video Demo) AND Storage Admins
  • CIFS and NFS Compression – Compress production data on Celerra to reduce disk space requirements including VMs
  • Dynamic SAN path load balancing – (via PowerPath)
  • At-Rest-Encryption – (via PowerPath w/RSA)
  • SSD, FC, and SATA drives in the same system – Balance performance and capacity as needed for your application
  • Local and Remote replication with array level consistency – (SnapView, MirrorView, etc)
  • Hot-swap, Hot-Add, Hot-Upgrade IO Modules – Upgrade connectivity for FC, FCoE, and iSCSI with no downtime
  • Scale to 1.8PB of storage in a single system
  • Simultaneously provide FC, iSCSI, MPFS, NFS, and CIFS access

All together, this is an impressive list of features for a single platform. In fact, while many of EMC’s competitors have similar features, none of them have all of them in the same platform, or leverage them all simultaneously to gain efficiency.  When CLARiiON CX4 and Celerra NS are integrated and managed as a single Unified storage system with EMC Unisphere there is tremendous value as I’ll point out below…

Improve Performance easily…

  • Install a couple SSD drives into a CLARiiON and enable FASTCache to increase the array’s read/write cache from the industry competive 4GB-32GB up to 2TB of array based non-volatile Read AND Write cache available to ALL applications including NAS data hosted by the array.
  • Install PowerPath on Windows, Linux, Solaris, AND VMWare ESX hosts to automatically balance IO across all available paths to storage.  PowerPath detects latency and queuing occuring on each path and adjusts automatically, improving performance at the storage array AND for your hosts.  This is a huge benefit in VMWare environments especially.
  • When VMWare releases the updated version of vSphere ESX that supports VAAI, ESX will be able to leverage VAAI support in the CLARiiON to reduce the amount of IO required to do many tasks, improving performance across the environment again.
  • Upgrade from 1gbe iSCSI to 10gbe iSCSI, or from 4gbe FiberChannel to 8gbe FiberChannel, without a screwdriver or downtime.
  • Provide NAS shared file access with block-level performance for any application using EMC’s MPFS protocol.

Improve Efficiency and cost easily…

  • Create a single pool of storage containing some SSD, some FC, and some SATA drives, that automatically monitors and moves portions of data to the appropriate disk type to both improve performance AND decrease cost simultaneously.
  • Non-disruptively compress volumes and/or files with a single click to save 50% of your disk space in many cases.
  • Convert traditional LUNs to more efficient Thin-LUNs non-disruptively using PowerPath Migration Enabler, saving more disk space.

Increase and Manage Capacity easily…

  • Add additional storage non-disruptively with SSD, FC, and SATA drives in any mix up to 1.8PB of raw storage in a single CLARiiON CX4.
  • Using FASTCache, iSCSI, FC, and FCoE connectivity simultaneously does not reduce total capacity of the system.
  • Expanding LUNs, RAID Groups, and Storage Pools is non-disruptive.
  • Migrating LUNs between RAID groups and/or Storage Pools is non-disruptive using built-in CLARiiON LUN Migration, as is migrating data to a different storage array (using PowerPath Migration Enabler)!
  • Balancing workload between storage processors is non-disruptive and at individual LUN granularity.

Protect your data easily…

  • Snapshot, Clone, and Replicate any of the data to anywhere with built in array tools that can maintain complete data consistency across a single, or multiple applications without installing software.
  • Maintain application consistency for Exchange, SQL, Oracle, SAP, and much more, even within VMWare VMs, while replicating to anywhere with a single pane-of-glass.
  • Encrypt sensitive data seamlessly using PowerPath Encryption w/RSA.

Maintain Flexibility…

  • While you can do all of these things quickly and simply, you still have the flexibility to create traditional RAID sets using RAID 0, 1, 5, 6, and 10 where you need highly predicable performance, or tune read and write cache at the array and LUN level for specific workloads.  Do you want read/write snapshots? How about full copy clones on completely separate disks for workload isolation and failure protection? What about the ability to rollback data to different points in time using snapshots without deleting any other snapshots?  EMC Storage arrays have been able to do this for a long time and that hasn’t changed.

There are few manufacturers aside from EMC that can provide all of these capabilities, let alone provide them within a single platform.  That’s the definition of simple, efficient, Unified Storage in my opinion.

Clariion CX4 – New Features in Flare 29

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EMC released FLARE 29 (04.29.000.5.001) for Clariion CX4 systems a few days ago.  The release of the CX4 hardware platform was a very significant upgrade for the Clariion series – moving to a 64bit operating system, implementing hot-add and hot-swap I/O modules, as well as multi-core CPUs for higher performance and scalability.  FLARE 28 was released to support the CX4 platform and introduced Virtual Provisioning (EMC’s name for thin provisioning) to the Clariion feature list.

According to the release notes FLARE 29 adds a couple of new features and builds on existing ones.  All of them will become available with the standard non-disruptive upgrade Clariion owners are accustomed to.

New Features in FLARE 29:

  • 2-port 10Gbps iSCSI IO modules are now available
  • The ability to hot swap IO modules for faster modules (ie: upgrade from 4gb FC to 8gb FC)
  • Idle SATA drives can now spin down to save power
  • iSCSI ports now support VLAN tagging
  • LUNs and MetaLUNs can now be shrunk if using new versions of Windows (ie: Windows 2008)

Additional Updates:

  • The maximum number of LUNs has been increased for all CX4 models (to 8192 for the CX4-960)
  • MirrorView now supports replicating to and/or from Thin provisioned LUNs
  • SANCopy now supports copying to and/or from Thin provisioned LUNs
  • The maximum number of MirrorView/Async sessions has increased to 256 and up to 64 consistency groups with up to 64 mirrors per group.  Up to 512 MirrorView/Sync sessions are supported on CX4-960 hardware.

The really big news here is with MirrorView.  When Virtual Provisioning was released in FLARE 28 on CX4 you could not use MirrorView with any thin LUNs, whether they were the source or destination.  This limited the use of thin LUNs to those applications and/or customers that don’t need or use array-based replication.  EMC’s RecoverPoint product did support thin LUNs but that is a separate, fairly expensive, solution.  The ability to replicate non-thin (fat) LUNs to thin LUNs could be really useful for maximizing the disk utilization at a DR location where performance isn’t a primary concern.

The added ability to upgrade I/O modules to faster versions while online is also very handy.  It means you can tackle problems like increasing iSCSI bandwidth or upgrading core infrastructure (ie: network and SAN switches) with little or no downtime on the storage system.  VLAN tagging with iSCSI can be useful for sharing a storage system between disparate server environments that need to be separated for security or performance reasons.

As a Clariion and MirrorView user myself, I look forward to taking advantage of the added thin provisioning support with our upcoming CX4-960.