I recently got hold of a copy of the new V-locity 4 product from Condusiv which was released last month. Condusiv is the new name for Diskeeper, whom you may have heard of before. I first came across them as a provider of software which specialized in optimizing I/O, primarily by preventing file fragmentation on NTFS in a Windows Guest OS. I blogged about them in the past on the vSphere Storage Blog after some discussions around defragmentation in the Guest OS. The new feature takes a portion of memory and uses it as a block cache. I did some preliminary tests with good ol’ IOmeter, and the initial results look quite good.
Category Archives: software
Error while adding NFS mount: NFS connection limit reached!
The advanced setting SunRPC.MaxConnPerIP defines the maximum number of unique TCP connections that can be opened for a given IP address. This is of particular interest to users of NFS. If the number of mounts to an IP address is more than SunRPC.MaxConnPerIP, then the existing connections for NFS mounts are shared with new mounts from the same IP address. Currently VMware supports a maximum of 128 unique TCP connections per ESXi host but also supports up to 256 mounts per host. So what options are available to configure ESXi hosts to allow the maximum number of NFS mounts?
vCenter 5.0U2 & ESXi 5.0U2 Released
Hi all,
Prior to the holidays, VMware released new versions of vCenter & ESXi on December 20th. There were new releases for both vSphere 5.0 & 5.1. In this post, I want to discuss release 5.0 Update 2. There were a number of notable fixes specific to storage which I wanted to highlight. I will follow-up with a look at storage enhancements in the new 5.1 release in a future post.
Atlantis ILIO – Diskless VDI & Services Feature Review
My first introduction to Atlantis ILIO was at a User Group meeting in the UK last year. I had a chat with Jim Moyle who explained the Atlantis ILIO product to me. Their primary focus is Virtual Desktop Infrastructure (VDI) storage and performance optimization solutions. In a nutshell, the ILIO software appliance sits in the I/O path between your hypervisor and storage and does what is essentially I/O acceleration. Since the appliance sits in the I/O path, it presents an iSCSI or NFS datastore at the front-end to the hypervisor, and at the backend, it is presented with NFS, iSCSI or Fibre Channel storage from the storage array. The appliance does a number of things such as inline deduplication, and also does Windows I/O optimization through Atlantis’ patented technologies. They can identify the different types of windows I/O, and intelligently process and characterize it. This allows them to determine which I/Os are latency sensitive & which are not, and prioritize accordingly. Atlantis claims that this technology massively reduces virtual desktop I/O to the back-end storage. They also claim that their technology reduces storage consumption, and makes VDI cost-effective from a storage perspective without sacrificing desktop performance (which has always been the Achilles heel of VDI).
At VMworld 2012, I had the opportunity to once again catch up with Jim, and also with Anjan Srinivas, the Director, Product Marketing at Atlantis Computing. I suppose the first thing to mention is that Atlantis Computing won the best of VMworld 2012 award in desktop virtualization for their Atlantis ILIO Diskless VDI product. I met with Anjan to ask about this ‘Diskless VDI’ product that won the award.
Atlantis ILIO Diskless VDI
Anjan told me that a key innovation this year was to use RAM as primary storage for stateless virtual machine images. This now enables customers to build elastic VDI data centers with just servers and software, moving the VDI market towards software defined data centers. This not only improves the CAPEX equation but also significantly simplifies the OPEX and management in data center. In the past Atlantis ILIO worked in conjunction with either a SAN/NAS or a local drive, as shown here.
Through intelligently optimizing how Microsoft Windows operating systems interact with VDI storage, and Atlantis’ inline deduplication, the amount of space required by an individual desktop is now so efficient that RAM becomes the store for the non-persistent virtual desktop. So no back-end storage required. In fact, I can now add that Colt Technology Services won the “Best of VMworld 2012″ Europe award for its Agilisys Desktop-as-a-Service (DaaS) project deployed with Atlantis ILIO Diskless VDI. That’s two awards at two VMworlds for Atlantis Computing and the Diskless VDI solution.
We then went on to discuss availability of the appliance, for instance when an ESXi host (or the appliance itself) has a crash. Since ILIO runs as an appliance on an ESXi host, it can use vSphere features like vSphere HA or FT, although according to Anjan, most customers use HA. For persistent desktops, there is no risk of data loss, which is the primary concern. ILIO, even though it sits on the I/O path, does not keep any data. There is a crash consistent file system with journaling in each appliance. For non-persistent environments, the desktops reside purely in RAM. VMware View will recognize that the desktops have gone down, and will makes those desktops available on another host. Users may experience a temporary disconnect, but will be reconnected when the desktop is re-instantiated with their profiles.
vSphere Integration
We then went on to talk about a few vSphere integration points. The first was around the management UI. ILIO Center is used to manage the appliance. It has a plugin to vCenter, and it appears as a separate tab.
Next we talked about VAAI integration. There isn’t any just yet, but Anjan pointed out that they are working towards VCAI (View Composer Array Integration) which is still in tech preview mode at the moment. Atlantis already has a technology called ILIO FastClone which is used to create full clone desktops (persistent or stateless) by manipulations of the metadata as opposed to working on actual data in just a few seconds. Anjan stated that this was something they began using internally for deploying large numbers of virtual desktops quickly for QA purposes, but very quickly realized that this is something that many customers would benefit from. Atlantis’ plan is to integrate this technology with VCAI so that when View Composer requests the creation of a desktop based on a linked clone, the clone creation overhead is handed off to Atlantis ILIO.
Atlantis ILIO Deployment Services
Anjan then gave me some breaking news from the Atlantis camp. He told me that they were on the verge of releasing a feature called Atlantis ILIO Deployment Services on October 24th. This was first announced at VMworld 2012. He stated that one of the primary concerns they have is that storage for VDI does not get deployed with optimal configuration & sizing, resulting in customers not seeing all the possible benefits from their solution. To address this, Atlantis ILIO Services provides fundamental integration with VMware View to automate the whole VDI deployment process in a few clicks. There are basically 4 steps involved:
1. Auto deploy ILIO on any number of ESXi servers
2. Sizes & configures the environment accordingly, selecting the optimal density of virtual desktops
3. Creates and registers a datastore with vSphere
4. Hands the datastore off to View Composer for the deployment of virtual desktops
The bottom line is that this automation of deployment should remove any user errors from the setup, and give customers the optimal ILIO deployment from the start as per Atlantis Computing best practices.
This is very impressive technology, and it is all done in software. Atlantis are really opening the doors for many customers who have not been able to pursue VDI due to storage costs either due to capacity or performance. And they certainly deserve those VMworld accolades.
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vSphere 5.1 Storage Enhancements – Part 3: vCloud Director
In this post, I want to highlight a number of storage improvements made in vSphere 5.1 that are going to be leveraged by the next release of vCloud Director.
Scalability
First off, we have the new file sharing scalability enhancements made in VMFS-5, which now allows up to 32 hosts to share a single file. This is covered in detail in part 1 of this vSphere 5.1 storage enhancements series of blog posts, but what this does mean for vCloud Director is that vApps deployed on linked-clones can now have many more hosts sharing the base disk on a VMFS-5.
VAAI NAS Offload
Sphere 5.0 introduced the offloading of linked clones for VMware View to native snapshots on the array via NAS VAAI primitives. You can read more about this here. vSphere 5.1 NAS VAAI enhancements will allow array based snapshots to be used for vCloud Director vApps based on linked clones, in addition to being used for VMware View.
When VMware vCloud Director does a fast provision of a vApp/VM, it will transparently use VAAI NAS to offload the creation of the subsequent linked clones to VAAI supported arrays.
Just like VAAI NAS support for VMware View in vSphere 5.0, this feature will also require a special VAAI NAS plug-in from the storage array vendor.
At the time of writing this article, NetApp already have this feature included in their next VSC release (4.1) which is currently in beta.
If “Fast Provisioning” is used on the Org vDC Storage settings AND the check box “Enable VAAI for fast provisioning” on the overall system Datastore settings is selected, it will trigger the right commands to use a native array-based snapshot for a linked clone instead of a standard redo log based one.
Profile Driven Storage Interoperability with vCloud Director
Storage Profiles are now represented in vCloud Director. Storage Profiles still must be configured from the vSphere layer, but they now surface up into vCloud Director. The storage profiles must first be added to a Provide vDC. For example, you might have Gold, Silver & Bronze storage profiles created. This then allows storage to be allocated and managed on a per ORG vDC. Again, continuing our example, this organization can only use datastores which are tagged as ‘Silver’. This support for Storage Profiles allows a high level of seperation between organizations at the storage level. Below is a snapshot of an ORG vDC with two storage profiles, one for iSCSI storage and one for NFS storage.
If the Storage Profile associated with a vApp is changed (this can be done via the properties of a vApp), the vApp is automatically Storage vMotion’ed to a compliant datastore. It is great to see vCloud Director leveraging this excellent vSphere feature.
Storage DRS Interoperability with vCloud Director
One of the major enhancements in vSphere 5.1 is to provide interoperability between Storage DRS and vCloud Director. This essentially means that vCloud Director 5.1 now recognises datastore cluster objects from Storage DRS. Just like Storage Profiles, the configuration of Storage DRS is done at the vSphere layer, but the resulting datastore clusters and their respective configuration surface up into vCloud Director. In order for this interoperability to work, Storage DRS now understands linked clones (which it didn’t do previously). Going forward, vCloud Director can now use Storage DRS for initial placement, space utilization and I/O load balancing of vApps based on linked clones.
Snapshots
The last feature introduced in vSphere 5.1 & vCloud Director 5.1 is the ability to take Virtual Machine snapshots from within vCloud Director. Previously one had to take these snapshots at the vSphere layer. As per the screen shot on the left, you can now Create, Remove and Revert a snapshot via the vCloud Director UI.
Although this might be considered a minor improvement, it does alleviate some additional administration which was necessary in previous versions of vSphere/vCloud Director.
I guess the next question then is how do you tell if you have a snapshot on the VM?
By default this information is not displayed on the Virtual Machine view. To show this information, select the option to display the Column headings which is on the right of the screen. Place a tick in the Snapshot column. You will now have a column denoting whether or not there is a snapshot for the Virtual Machine as per the diagram below,
It is nice to see these vSphere storage features being leveraged by vCloud Director. It’s especially nice to see some of the interoperability between products and features.
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