Tag Archives: Celerra

Having performance issues with Celerra and NFS Datastore performance ? patch ! Patch ! Patch !

I sat in on an interesting session yesterday which gets under the covers of VMware performance on NFS datastores  hosted on Celerra NS series. This was presented by a chap called Ken Cantrell who works for EMC engineering and was off the back of the fact that feedback from the field showed in many cases that some customers VMware estate simply wasn’t performing using NFS on Celerra. This is not the case for everybody, but it certainly was an issue. Essentially what was happening is the Celerra was dealing with an extensive amount of NFS calls to the UxFS log (predominantly Getattr type calls) and it was slowing down response types back to the host. EMC tested a workload on the Celerra using DART 6.0.4 using Jetstress. Jetstress effectively simulates exchange workload and also halts the benchmark if response times exceed 20 milliseconds on the basis of 20 milliseconds being to poor for a exchange. EMC were seeing that with the base version of DART 6 response time were exceeding 25 Milliseconds for the Exchange workload they tested on an exchange VM sitting on a Celerra hosted NFS datastore. EMC then released a patch upgrade which brought that down to sub 15 ms. EMC then released an experimental epatch (DART which brought response times down further to sub 10ms (closer to 6ms).

So bottom line is…  don’t just suffer poor performance. Feed back to EMC if you see issues and also keep an eye on patch updates to the OS. They are there to resolve noted issues !


A good post on ECN with details of the new patch :


A good blog comparing iSCSI Vs NFS for VMware:


A good blog post by Jason Boche comparing the performance delta between Dart 6.0.4 and Dart


Protocol considerations with VMware

A good video I came across from EMC discussing some storage protocol considerations when looking at VMware.

Unisphere.. yay !! what about Celerra Manager and Advanced Manager on the NX4 ?

Right, so EMC have got rid of Basic and advanced editions of Celerra Manager and replaced them Unisphere. Fantastic ! no more questions about what the difference is between the basic and advanced edition of Celerra Manager !!  Naaay..    Interest has peaked on the Celerra NX4; EMC’s little Unified storage box must be hitting a sweet spot as we’re getting lots of requests..  and this box still runs Celerra Manager.

So, What do you need to know about Celerra manager when comparing the two editions.

The Advanced Edition gives you the ability to manage multiple Celerra’s – So if replicating two of Celerra’s, I would strongly suggest the Advanced Edition.

The Advanced Edition gives you more control of Provisioning Disk – The Basic edition will automate management of how disks are carved up in order to present file systems and shares out to the network. I nice feature for the IT manager with not enough time on his hands to do this. But if you want to carve up Meta’s, volumes and disks in a specific way to meet specific performance requirements, then you need the advanced edition to circumnavigate the Automated volume manager.

The advanced edition has a inbuilt migration tool called CDMS (Celerra Data Migration Service) – I would advise that tool is reserved for only those who are well versed in Celerra and migrations. But effectivly it offers migration capability for file data to Celerra with minimal down time. If you are going to use this, make sure you know what you’re doing or engage an EMC partner.

Those are the important bits you need to know..     any further questions…    ask your EMC Partner

Dedupe your file data !! save our hard drives !!

Just a little video I put together showing file server consolidation (in a blue peter here’s one I made earlier style). 2 minutes, nothing too fancy..   just a bit of fun.  

(best watched in full screen)

I do hope geek is the new chic …    because if not…   I feel dirty

Iomega/EMC’s new lovechild

Iomega first started life selling removable storage. The world marvelled at the might of the 200MB Zip drive, brought gifts of  gold , frankincense and murr as offerings to the almighty Jazz drive and sacrificed livestock in awe of the the Ditto Drive  (I exagerate..  but bear with me, I’m setting the scene). Then, as removable storage media started to give way to internet and USB drives became the standard for removable storage..  we started to see the likes of the zip and jazz drive fade away.

So..  out with the old, in with the new ? No..  Now Iomega have a massive play in the consumer space for External Hard drives and networked storage. The upper end of the networked storage range was the IX4 (now on its second generation). A nice tidy box which would hold up to 8TB of RAW capacity and fit well in a remote office environment, home office, even as a media server for your movies and music (all legitimately obtained of course). They even did a rackmount NAS device..  Brilliant !!

But what if you need a little more grunt… a bit more redundancy, scalability.. something more feature rich. Iomega/EMC are on the verge of releasing the IX12. This box fits nice and snug between the IX4-200R and EMC’s Celerra NX4; it supports up to 24TB of RAW capacity, supports all the RAID types you’d ever want to use and has 4 Gigabit ports which can support up to 256 iSCSI initiators (servers) or 256 LUN’s for block level access. All the other usual protocols still apply in the oh so familiar forms of CIFS, NFS, FTP, HTTP, etc and there are even a few nice bells and whistles such as port aggregation, DFS, array based replication, WebDav Support for online collaboration and it also sports drive spin down (very cool if its being used for a backup to disk or archive target). 

The IX12 has also been certified by a number of other vendors; it is obviously certified and on VMwares Hardware compatibility List for shared storage (also supported by a number of other virtualization vendors). Microsoft have verified that it will support Exchange 2010 Mailstores for environments of up to 250 users.

Its being stated by Iomega that these boxes are sitting in at between $5,000 and $10,000 list,  so will help EMC break even further into the lower SMB market. Personally, I think this box will play really well in spaces such as remote office,  graphic design organisations, departmental dedicated storage, backup to disk targets (admittedly would be more compelling if it supported NDMP, but we’ll leave that to the big boys), archive storage for the likes of EMC’s SourceOne, EV, Commvault, etc…

I’ll put together a more clear and concise post after the announcements to come, but I think Iomega could be onto a winner on this one..

Managing Celerra from Vmware

EMC of late have been very good at increasing the level of integration between their storage and the VMWare platform. First it was DRS integrating with EMC QOS Manager, then the ability to view what VM’s reside on SAN storage from within Clariions Navisphere Manager, then replication manager was pulled inline to facilitate machine consistent snaps/replication with vmware using their VMFS proxy.

All very cool stuff, but now EMC are pulling the ability to manage storage from within EMC’s Celerra platform amd into VMWare’s VI Client.  As of release 5.6.48 of DART (Dart is the firmware/OS for Celerra), you will be able to manage the creation and management of NFS exports from within VMWare and perform the following actions :

Create an NFS file system and mount to ESX systems to be used as a VMware data store. File systems created with the plug-in will be automatically deployed with EMC and VMware best practices, including Celerra Virtual Provisioning.

Data store (NFS file system) extension extends the Celerra file system that is exported to the ESX cluster.

Compress the VMware VMDK files associated with a virtual machine, a folder (of multiple virtual machines), an ESX server, or a whole data store. Decompress a previously compressed VMDK or set of VMDK files.

Full Clone—Make full copies of virtual machine VMDK files using new Celerra-based functionality

Fast Clone—Make thin copies of virtual machine VMDK files instantly using new Celerra NFS file-based snap functionality



Below is a very good video demonstation provided by the one and only virtualgeek Mr Chad Sakac, demonstrating the feature

The Long awaited….

A few new things comming out on EMC’s mid tier storage range to look out for.  One of which is very discreetly named Project Odin and will make the life of EMC Celerra users and resellers alike a touch easier. Its a management console to manage Celerra and its respective back end Clariion rather than having to jump into navisphere to manage the Clariion directly ! from what I gather its will run on any DART or FLARE OS and is pointed at the system to which it needs to manage via IP address, then the appropriate profile is loaded to reflect the functions relevant to said Clariion/Celerra..  about time !!   as I understand it, there will be an announcement in feb..  but it won’t be going GA for a little while. Watch this space !!