Firstly an apology for those who regularly read my blog – I’ve just returned from three months paternity leave where I was largely ‘off the grid’ and had very little to do with technology and lots to do with changing nappies and singing nursery rhymes in public! I could write a blogpost about technology parallels but that’s already been covered by Bob Plankers so I thought I’d at least check on industry developments and write up the events that caught my attention in those months. In no particular order;
In the community vExpert applications opened for 2013 and CloudCred was launched (VMware’s attempt to gamify their learning paths), vOpenData was launched to great success, plus Storage Field Day #3 and LonVMUG offered their usual excellent mix of technology and social.
Obviously three months isn’t very long in strategic terms although there are a couple of interesting developments. With the acquisition of Virsto and the announcement of NSX VMware are progressing their ‘software defined’ datacentre vision while the hybrid cloud move was leaked last year and now seems obvious given their lack of progress against rival public cloud providers like Amazon. EMC aren’t ignoring the threat that the shift towards open source, commodity, and ‘software defined’ products poses to their existing product lines although it’ll be interesting to see how other storage vendors respond to the same challenges. From my limited viewpoint (my company aren’t really doing ‘cloud’ at all if you ignore shadow IT) OpenStack seems to be gaining ground – I see more coverage and more people I know getting involved.
Anything I’ve missed? What’s in store in the next twelve weeks? Interesting times!
For those of us in the UK it may feel as if winter has gone on forever but finally the sun has shown it’s face and everyone has a new spring in their step. What to do with all that pent up energy?
Attend the London VMUG on Thursday 25th April of course! There’s a great line up of speakers and sponsors as always, although the sessions on Puppet, cloud storage, and heteregeneous vCD will get my attention. Below is the full agenda but note that you need to register for free in advance.
Where to go for the usergroup
London Chamber of Commerce and Industry 33 Queen Street London, EC4R 1AP (map)
Where to go for drinks afterwards (which you should definitely do, it’s where the good stuff happens. It’s a five minute walk from the usergroup)
The Pavilion End pub 23 Watling Street, Moorgate London EC4M 9BR (map)
I’ve recently installed the BetterWPSecurity WordPress plugin, and found that while it’s very useful and does increase the security of WordPress it can also break your site.
Ah, Monday morning and the start of my three months paternity leave looking after my six month old son Zach. During his morning nap I logged into my blog to work on an article and noticed that my blog wasn’t loading articles correctly even though the home page worked just fine. Investigating further and looking at my site stats (I use both the Jetpack plugin and Google Analytics) clearly showed that something broke at the start of the weekend – I had nearly no traffic all weekend. Having just referred a colleague to my site for some information and on my first day of paternity leave (ie less time on my hands, not more as some may think) this was definitely not ideal timing!
My first step was to check my logs for information, in this case the BetterWPSecurity log for changed files. This revealed that the .htaccess file in the root directory was changed late on Friday night at 11:35pm – and I knew that wasn’t me as I was tucked up in bed. My first thought was a hack as the .htaccess file permits access to the site but there was no redirect or site graffiti and the homepage still worked so that didn’t seem likely. I logged in via SSH to have a look at the .htaccess file but didn’t see anything obvious although I’m no WordPress expert.
My priority was to get the blog working again so I tried restoring a copy of the changed file from the previous week’s backup (made via the BackWPUp plugin) only to find the backup wasn’t useable. Bad plugin! Luckily I’m a believer in ‘belt and braces’ and I knew my hosting company, EvoHosting, also took backups. I logged a call with them and within the hour they’d replied with the contents of the file from a week earlier. Sure enough the file had been changed but looking at the syntax it appeared to be an error rather than malicious hack.
My .htaccess file when the site was working;
# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPress
My .htaccess file after the suspicious change;
# BEGIN Better WP Security
Order allow,deny
Allow from all
Deny from 88.227.227.32
# END Better WP Security
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
I backed up the suspicious copy of the file (for future reference, ie writing this blogpost), restored the original et voila – the blog was working again. Step one complete, now to find the root cause…
Part of any diagnostic process is the question ‘what’s changed?’ and I had a suspicion that BetterWPSecurity could be the culprit as I’d only installed it a few weeks earlier. There was also the obvious issue of the new code in the .htaccess file which looked to belong to BetterWPSecurity. I checked the site access logs which confirmed my hypothesis – someone had attempted to break into my site and while attempting to block the attacker BetterWPSecurity had mangled my .htaccess file. The logs below have been truncated to remove many of the brute force login attempts (there were plenty more) but note that on the final line (after BetterWPSecurity has blocked the attacker) the HTML return code was 418 (“I’m a teapot”) rather than 200 plus the suspect IP 88.227.227.32 is the same as the one denied in the mangled .htaccess file. Yes, you read that right, “I’m a teapot”! Here’s a full explanation for that April Fool’s error code.
So BetterWPSecurity led me to the fault but also caused it. To be fair the plugin does warn you which settings are potentially going to cause issues but I’d assumed that it wouldn’t be me – dangerous things assumptions. I’ve rectified the issue by restricing BetterWPSecurity from altering core system files as shown in the screenshot below;
My blog is fixed and I’m feeling quite chuffed that it was all resolved during a long lunchbreak – not a bad day’s work if I do say so myself! Lesson for today? Take warnings seriously and have multiple backups!
I keep hearing that ‘IT is becoming a commodity‘, cloud computing is ‘like a utility‘, and recently I’ve heard the term ‘fungibility’ applied to computing on multiple occasions. The technologies behind cloud computing are driving these changes but what does it mean to be a commodity, what on earth is fungibility, and what’s it got to do with cloud computing? In this post I’ll explore the fungibility of storage and in a future blogpost the wider impact to cloud computing.
Lets dig into what fungibility is and why it’s important. Wikipedia defines it as;
Fungibility is the property of a good or a commodity whose individual units are capable of mutual substitution, such as crude oil, shares in a company, bonds, precious metals, or currencies.
In plain English fungibility means something is interchangeable – a common example is money. If someone owes you ten dollars you don’t care if they pay you one ten dollar bill, two fives, or ten ones – you get essentially the same thing. Another example is that you’re supposed to eat five portions of fruit and veg every day but you could eat five fruits, five veg, or a mixture – they’re fungible (interchangeable).
Now we know what is it but who cares if something is fungible?
for consumers fungibility is a good thing as it increases competitionand flexibility – you can buy your commodity from anyone, often driving down prices
for providers fungibility could be good and bad. The increased competition might benefit your competitors but history has shown that once a market becomes a commodity it tends to grow, leading to more business for all involved.
Note that just because a commodity is fungible it doesn’t mean there’s no differentiation. Many metals are considered fungible – a tonne of molybdenum may be valued the same whether it’s mined from Australia or Europe. If you need that metal in Europe however you’ll incur shipping costs if you buy the Australian sourced tonne so you’ll pay a premium to get the supplier from Europe. It’s this differentiation which enables trade – more on this in the followup post coming shortly.
Fungibility and storage
Two of the references I’ve heard were in regard to storage and whether it is or isn’t fungible, so that’s where I’ll start. Virsto’s argument during their storage hypervisor presentation at SFD2 argued that while CPU and memory are fungible (specifically in virtualized environments) storage isn’t and is therefore a pain point (which they aim to solve obviously). In his 2013 predictions article Arthur Cole at IT BusinessEdge sees storage becoming a fungible commodity which has ramifications for how it’s consumed.
Uncertainty over whether storage is fungible or not is understandable – my first reaction when I thought about it was ‘no chance’! I’m a storage admin in my current job and each storage request is slightly different – there are too many variable factors which affect the outcome that you couldn’t consider two requests as interchangeable unless the solution was from the same vendor and with the same configuration. Here’s just some of the factors when specifying solutions or diagnosing storage issues;
Capacity (typically in GB or TB)
Performance – throughput, latency, IOps
Workload – read/write ratio, block sizes, sustained or variable demand
Availability – HA, clustering, support, SLAs etc
Backups – snapshots, long term archiving, restore times
Security – location, governance, compliance
Crucially however, as a storage provider I have a different perspective to a consumer of my storage. For a consumer most of this complexity is invisible, hidden behind either a technical or business abstraction – hence why a storage request often only considers capacity (much to my frustration!). What I get concerns me, not how it’s implemented. If you look at storage from the customer’s perspective then it’s a simpler construct and provided it satisfies the user’s expectations it can be considered fungible. All those variables can differentiate one service from another but for many services they’re of secondary importance.
Take a simple consumer example – Dropbox. I’ve used this excellent service for quite a few years and the only thing I really care about is how much storage I can consume and that it works reliably. I assume that it’s always available, that I can get my files back when needed, and that the storage provided by Dropbox can handle what I throw at it. If I don’t like the service offering I can move to one of their competitors like Crashplan, Skydrive, or Bitcasa and while the functionality is slightly different (maybe they don’t all support Linux clients for example) I can compare prices and pick the one that best suits me.
At the enterprise level companies like Amazon, with their S3 and Glacier services, compete with other industry heavyweights like Google’s Cloud Storage, Microsoft’s Azure, Nirvanix etc. Take up of these services started with the Web 2.0 generation but today’s they’re starting to tackle the ‘legacy’ enterprises. This is the more complex world where the factors I mentioned above are more relevant – if someone offered me some ‘cloud’ storage versus some traditional onsite storage (using Netapp’s or EMC gear) then I’d expect them to deliver completely different experiences. Rodney Rogers, the CEO of Virtustream, has recently written an excellent piece about why Amazon may struggle when delivering to the enterprise and I’d agree completely – the demands of the average enterprise are not the same as the Web 2.0 companies running commodity hardware. There are plenty of successful cloud storage companies doing business in the enterprise world today but as Gartner warn you need to be on your guard as the services offered vary widely and are not therefore easily compared – they’re not fungible. They also indicated that 20% of companies are already using cloud storage so one hopes it’s delivering some value. Apologies for mentioning the ‘G******’ word so often!
The answer to ‘is storage fungible?’ is the classic ‘it depends’. For some, typically consumer, requirements I’d say it is but for the more demanding enterprise it’s not there yet.
Late last week I joined an illustrious line of community bloggers, vendors, and authors by having a ‘chinwag’ with Mike Laverick. Anyone who knows Mike knows that a quick chat can easily last an hour for all the right reasons – he’s passionate about VMware and technology in general and good at presenting complex ideas in an easily understood manner. I guess that’s why he recently became a senior cloud evangelist for VMware! We discussed a few topics which are close to my heart at the moment;
Oracle
vCloud Director
Storage Field Day
You can listen to the audio (MP3 or the iPod/iPad friendly M4V) or watch the YouTube video. As time is limited on the actual chinwag I thought I’d offer a few additional thoughts on a couple of the topics we discussed.
Oracle and converged infrastructure
I didn’t want to get embroiled in a discussion about Oracle’s support stance on VMware as that’s been covered many times before but it’s definitely still a barrier. Some of our Oracle team have peddled the ‘it’s not supported’ argument to senior management and even though I’ve clarified the ‘supported vs certified’ distinction it’s a difficult perception to alter. Every vendor wants to push their own solutions so you can’t blame Oracle for wanting to push their own solution but it sure is frustrating!
Of more interest to me is where converged infrastructure is going. As we discussed on the chinwag Oracle are an interesting use case for converged infrastructure (or engineered systems, pick your terminology of choice) because it includes the application tier. Most other converged offerings (VCE, FlexPod, vStart and even hyperconverged solutions like Nutanix) tend to stop at the hypervisor, thus providing a abstraction layer that you can run whatever workload you like on. Oracle (with the possible exception of IBM?) may be unique in owning the entire stack from hardware all the way up through storage, networking, compute, through to the hypervisor and up to their crown jewels, the Oracle database and applications. This gives them a position of strength to negotiate with even when certain layers are weak in comparison to ‘best of breed’, as is the case with OracleVM. Archie Hendryx explores this in his blogpost although I think he undersells the advantage Oracle have of owning a tier 1 application – Dell’s vStart or VCE’s vBlock may offer competition from an infrastructure perspective but my company don’t run any Dell or VCE applications. If you’re not Oracle how do you compete with this? You team up to provide a ‘virtual stack’ optimised for various workloads – today VDI is the most common (see reference architectures from Nexenta, Nimble Storage et al). As the market for converged infrastructure grows I think we’ll see more of these ‘vertical’ stack style offerings.
After I described my problem getting vCD tabled as a viable technology for lab management Mike rightly pointed out that many people are using vCD in test and dev – maybe more than in production. I agree with Mike but suspect that most are using dev/test as a POC for a production private cloud, not as purpose built lab management environment. I didn’t get time to discuss a couple of other points which both complicate the introduction of vCD even if you have an existing VMware environment;
Introducing vCD (or any cloud solution for that matter) is potentially a much bigger change compared to the initial introduction of server virtualisation. In the latter the changes mainly impacted the infrastructure teams although provisioning, purchasing, networks and storage were all impacted. If you’re intending to deliver test/dev environments you’re suddenly incorporating your applications too, potentially including the whole development/delivery lifecycle. If you go the whole hog to self-service then you potentially include an even larger part of the business right up to the end users. That’s a very disruptive change for some ‘infrastructure guy’ to be proposing!
vCD recommends Enterprise+ licencing which means I have to argue for the highest licencing level for test/dev, even if I don’t have it in production
Flash storage continues to rapidly disrupt the storage marketplace
The desire for more scalable systems is driving changes in the architecture of enterprise storage
To people immersed in storage these trends are well known and have been covered increasingly over the last couple of years (flash has been in mainstream arrays in some form since 2008). I’ve written this article to consolidate my own thoughts rather than as the traditional end of year predictions – ‘if you can’t explain it you don’t understand it‘ is something I believe and one of the principal reasons I enjoy blogging. Despite my interest in storage these events made me realise I’ve taken my eye off the ball and I’m now playing catchup!
Most of the vendor and panel sessions at the conference concentrated on the flash aspects – tiered vs cache, should you use a hybrid or all flash array (or no array at all in Nutanix’s case) although there was also discussion of the scalability of various architectures and technologies. Flash’s key advantage is performance – when compared to spinning disk it’s orders of magnitude faster and much of the current innovation is in trying to overcome its other constraints of cost, lifecycle, form factor etc. It’s not just performance that’s driving the current industry changes however – the desire for greater scalability is driving storage from a centralised model to a more distributed architecture (as described very eloquently by Chris Evans).
Combined these factors imply a major shakeup in the storage industry – it’s going to be a fun few years!
Flash disrupts the marketplace
Unless you’ve been hiding under a very big rock you can’t have missed the mass market arrival of flash devices into almost every aspect of the market, both for consumers and enterprises. Read more…
A quick post to say that Netapp have released v2.1 of their Windows MMC management tool, OnCommand System Manager (the download link is the bottom right, NOW account required). This new update brings the usual incremental fixes along with support for Flash Pools, Infinite Volumes (a feature of ONTAP 8.1.1 in cluster mode), and multidisk carrier shelves. It’s also moved to a 64 bit architecture – my ‘upgrade’ simply uninstalled the 32bit version and installed the 64 bit one.
For compatibility the release notes state;
Data ONTAP 7.3.x (starting from 7.3.7)
Data ONTAP 8.0 or later in the 8.0 release family operating in 7-Mode
Data ONTAP 8.1 or later in the 8.1 release family operating in 7-Mode
Data ONTAP 8.1 or later in the 8.1 release family operating in Cluster-Mode
However checking the Netapp compatibility matrix shows that this release is ‘officially’ supported on a smaller number of ONTAP releases, notably ONTAP 7.3.7 or newer (excluding 7.3.4 etc) and 8.03 or newer (excluding 8.01, 8.02 etc). I suspected this was simply timing and that once the new release has been around for longer it would be validated against more ONTAP releases. However I tried it against a few of my filers running a mixture of 8.01p2 and 8.02P6 and found one issue straightaway. The new network checker wouldn’t run against the 8.01p2 controllers as apparently they don’t support the necessary API calls.
If you’re running some of these older ONTAP releases proceed with caution!
It’s that time of year when I book the next London VMUG session into my calendar and rather than my usual ‘here’s the agenda, you should go‘ blogpost I thought I’d recap what the last year has delivered. If this doesn’t convince you that there’s value in attending a free event where you could have learnt all the topics listed below as well as networking with your peers then nothing will.
If there’s a topic you’d like covered or if you’d like to present something yourself get in touch with the organising commmittee. I’m planning to present at one of next year’s VMUG sessions (it’s about time!) because it’s a user group and real world experience can be gold dust for others to learn from. I’m told we’re a friendly audience!
Darren Woollard ran a couple of interactive VMware design workshops
This year saw the first EMEA NDA session which covered the future roadmap from VMware. Exciting stuff but not available online for obvious reasons – you had to be there!
You want real world cloud case studies? Pete Rossi showed that ‘Government Can Run vCloud, How Skyscape Did It’ (no slides available)
Applications. As infrastructure professionals we may not spend much of our time thinking about the applications but eventually we all have to admit they rule the roost;
Nontechnical sessions. While I have my head in the technical clouds it’s good to look over the parapet once in a while and these sessions helped me do just that;
A thought provoking session on DevOps and service management from Alex Smith. This topic was probably out of many people’s comfort zones but it’s good to learn something new and challenge your thinking.
I could mention the giveaways (iPad, Fusion-IO card, t-shirts, AppleTV etc) and the free beers afterwards, the fact we had at least five VCDX’s presenting and the live labs from EMC, VMTurbo, and Embotics etc but you’re already sold right?
In this article I’m going to talk about Zerto, a data protection company specialising in virtualized and cloud infrastructures who I recently saw as part of Storage Field Day #2. They’ve presented twice before at Tech Field Days (as part of their launch in June 2011 and Feb 2012) so I was interested to see what new developments (if any) were in store for us. In their own words;
Zerto provides large enterprises with data replication solutions designed specifically for virtualized infrastructure and the cloud. Zerto Virtual Replication is the industry’s first hypervisor-based replication solution for tier-one applications, replacing traditional array-based BC/DR solutions that were not built to deal with the virtual paradigm.
When I first heard the above description I couldn’t help but think of VMware’s SRM product which has been available since June 2008. Zerto’s carefully worded statement is correct in that SRM relies on storage array replication for maximum functionality but I still think it’s slightly disingeneous. To be fair VMware are equally disingeneous when they claim “the only truly hypervisor level replication engine available today” for their vSphere Replication technology – marketing will be marketing! Later in this article I’ll clarify the differences between these products but let’s start by looking at what Zerto offers.
Zerto offer a product called Zerto Virtual Replication which integrates with vCenter to replicate your VMware VMs to one or more sites in a simple and easy to use manner. Since July 30th 2012 when v2.0 was released it supports replication to various clouds along with advanced features such as multisite replication and vCloud Director compatibility. Zerto are on an aggressive release schedule given that the initial release (which won ‘Best of Show’ at VMworld 2011) was only a year earlier but in a fast moving market that’s a good thing. For an entertaining 90 second introduction which explains what if offers better than I could check out the video below from the companies website;
Just as server virtualization opened up possibilities by abstracting the guest OS from the underlying hardware so data replication can benefit from moving ‘up the stack’ away from the storage array hardware and into the hypervisor. The extra layer of abstraction lifts certain constraints related to the storage layer;
Array agnostic – you can replicate between dissimilar storage arrays (for example Netapp at one end and EMC at the other). For both cloud and DR scenarios this could be a ‘make or break’ distinction compared to traditional array replication which requires similar systems at both ends. In fact you can replicate to local storage if you want – if you’re one of the growing believers in the NoSAN movement that could be useful…
Storage layout agnostic – because you choose which VMs to replicate rather than which volume/LUN on the array you’re less constrained when designing or maintaining your storage layout. When replicating you can also change between thin and thick provisioning, or from SAN to NAS, or from one datastore layout to another. A typical use case might be to replicate from thick at the source to thin provisioning at the DR location for example. There is a definite trend towards VM-aware storage and ditching LUN constraints – you see it with VMware’s vVols, storage arrays like Tintri and storage hypervisors like Virsto so having the same liberating concept for DR makes a lot of sense.
Zerto goes further than just being ‘storage agnostic’ as it allows further flexibility;
Replicate VMs from vCD to vSphere (or vice versa). vCD to vCD is also supported. This is impressive stuff as it understands the Organization Networks, vApp containers etc and creates whatever’s needed to replicate the VMs.
vSphere version agnostic – for example use vSphere 4.1 at one end and vSphere 5.0 at the other. For large companies which can typically lag behind this could be the prime reason to adopt Zerto.
With any replication technology bandwidth and latency are concerns as is WAN utilisation. Zerto uses virtual appliances on the source and destination hosts (combined with some VMware API calls, not a driver as this article states) and therefore isn’t dependent on changed block tracking (CBT), is storage protocol agnostic (ie you can use FC, iSCSI or NFS for your datastores) and offers compression and optimisation to boot. Zerto provide a profiling tool to ‘benchmark’ the rate of change per VM before you enable replication, thus alllowing you to predict your replication bandwidth requirements. Storage I/O control (SIOC) is not supported today although Zerto are implementing their own functionality to allow you to limit replication bandwidth. Today it’s done on a ‘per site’ basis although there’s no scheduling facility so you can’t set different limits during the day or at weekends.
VMware’s vSphere is the only hypervisor supported today although we were told the roadmap includes others (but no date was given). With Hyper-V v3 getting a good reception I’d expect to see support for it sooner than later and that could open up some interesting options.
Zerto’s Virtual Replication vs VMware’s SRM
Let’s revisit that claim that Zerto is the “industry’s first hypervisor-based replication solution for tier-one applications“. With the advent of vSphere 5.1 VMware now have two solutions which could be compared to Zerto – vSphere Replication and SRM. The former is bundled free with vSphere but is not comparable – it’s quite limited (no orchestration, testing, reporting or enterprise-class DR functions) and only really intended for data protection not full DR. SRM on the other hand is very much competition for Zerto although for comparable functionality you require array level replication.
When I mentioned SRM to the Zerto guys they were quick to say it’s an apples-to-oranges comparison which to a point is true – with Zerto you specify individual or groups of VMs to replicate whereas with SRM you’re still stuck specifying volumes or LUNs at array level. Both products have their respective strengths but there’s a large overlap in functionality and many people will want to compare them. SRM is very well known and has the advantage of VMware’s backing and promotion – having a single ‘throat to choke’ is an attractive proposition for many. I’m not going to list the differences because others have already done all the hard work;
Looking through the comparisons with SRM there are quite a few areas where Zerto has an advantage although to put it in context check out the pricing comparison at the end of this article; NOTE: Since the above comparison was written SRM v5.1 has added support for vSphere Essentials Plus but everything else remains accurate
RTO in the low seconds rather than 15 mins
Compression of replication traffic
No resync required after host failures
Consistency groups
Cloning of the DR VMs for testing
Point in time recovery (up to a max of 5 days)
The ability to flag a VMDK as a pagefile disk. In this instance it will be replicated once (and then stopped) so that during recovery a disk is mounted but no replication bandwidth is required. SRM can’t do this and it’s very annoying!
vApps supported (and automatically updated when the vApp changes)
vCloud Director compatibility
If you already have storage array replication then you’ll probably want to evaluate Zerto and SRM. If you don’t have (or want the cost of) array replication or want the flexibility of specifying everthing in the hypervisor then Zerto is likely to be the best solution.
DR to the Cloud (DRaaS)
Of particular interest to some customers and a huge win for Zerto is the ability to recover to the cloud. Building on the flexibility to replicate to any storage array and to abstract the underlying storage layout allows you to replicate to any provider who’s signed up to Zerto’s solution. Multisite and multitenancy functionality was introduced in v2.0 and today there are over 30 cloud providers signed up including some of the big guys like Terremark, Colt, and Bluelock. Zerto have tackled the challenges of a single appliance (providers obviously wouldn’t want to run one per customer) providing secure multi-tenant replication with resource management included.
vCloud Director compatibility is another feather in Zerto’s cap, especially when you consider that VMware’s own ‘vCloud Suite’ lags behind (SRM only has limited support for vCD). One has to assume that this will be a short term advantage as VMware have promised tighter integration between their products.
Pricing
Often this is what it comes down to – you can have the best solution in the market but if you’re charging the most then that’s what people expect. Zerto are targeting the enterprise so maybe it shouldn’t be a surprise that they’re also priced at the top end of the market. The table below shows pricing for SRM (both Standard and Enterprise edition) and Zerto;
SRM Standard
SRM Enterprise
Zerto Virtual Replication
$195 per VM
$495 per VM
$745 per VM
As you can see Zerto costs a significant premium over SRM. When making that comparison you may need to factor in the cost of storage array replication as SRM using vSphere Replication is severely limited. These are all list prices so get your negotiating hat on! We were told that Zerto were seeing good adoption from all sizes of customer from 15VMs through to service providers.
Final thoughts
I’ve not used SRM in production since the early v1.0 days and I’ve not used Zerto in production either so my thoughts are based purely on what I’ve read and been shown. I was very impressed with Zerto’s solution which certainly looks very polished and obviously trumps SRM in a few areas – hence why I took the time to investigate and write up my findings in this blogpost. From a simple and quick appliance based installation (which was shown in a live demo to us) through to the GUI and even the pricing model Zerto’s aim is to keep things simple and it looks as if they’ve succeeded (despite quite a bit of complexity under the hood). If you’re in the market for a DR solution take time to review the comparison with SRM above and see which fits your requirements and budget. Given how comprehensive the feature set is I wouldn’t be surprised to see this come out on top over SRM for many customers despite VMware’s backing for SRM and the cost differential.
Multi-hypervisor management could be a ‘killer feature’ for Zerto. It would distinguish the product for the forseeable future (I’d be surprised to see this in VMware’s roadmap anytime soon despite their more hypervisor friendly stance) and needs to happen before VMware bake comparable functionality into the SRM product. Looking at they way VMware are increasingly bundling software to leverage the base vSphere product there’s a risk that SRM features work their way down the stack and into lower priced SKU’s – good for customers but a challenge for Zerto. There’s definitely intriguing possibilities though – how about replicating from VMware to Hyper-V for example? As the use of cloud infrastructure increases the ability to run across heteregenous infrastructures will become key and Zerto have a good start in this space with their DRaaS offering. If you don’t want to wait and you’re interested in multi-hypervisor management (and conversion) today check out Hotlink (thanks to my fellow SFD#2 delegates for that tip).
I see a slight challenge in Zerto targeting the enterprise specifically. Typically these larger companies will already have storage array replication and are more likely to have a mixture of virtual and physical and therefore will still need array functionality for physical applications. This erodes the value proposition for Zerto. Furthermore if you have separate storage and virtualisation teams then moving replication away from the storage array could break accepted processes not to mention put noses out of joint! Replication at the storage array is a well accepted and mature technology whereas virtualisation solutions still have to prove themselves in some quarters. In contrast VMware’s SRM may be seen to offer the best of both worlds by offering the choice of both hypervisor and/or array replication – albeit with a significantly less powerful replication engine (if using vSphere Replication) and with the aforementioned constaints around replicating LUNs rather than VMs. Zerto also have the usual challenges around convincing enterprises that as a ‘startup’ they’re able to provide the expected level of support – for an eloquent answer to this read ‘Small is beautiful’ by Sudheesh Nair on the Nutanix blog (who face the same challenges).
Disclosure: the Storage Field Day #2 event is sponsored by the companies we visit, including flight and hotel, but we are in no way obligated to write (either positively or negatively) about the sponsors.
While upgrading my home lab recently I found myself reconsidering the scale up vs scale out argument. There are countless articles about building your own home lab and whitebox hardware but is there a good alternative to the accepted ‘two whiteboxes and a NAS’ scenario that’s so common for entry level labs? I’m studying for the VCAP5-DCD so while the ‘up vs out’ discussion is a well trodden path there’s value (for me at least) in covering it again.
There are two main issues with many lab (and production) environments, mine included;
Memory is a bottleneck and doubly so in labs using low end hardware – the vCentre appliance defaults to 8GB, as does vShield Manager so anyone wanting to play with vCloud (for example) needs a lot of RAM.
Affordable yet performant shared storage is also a challenge – I’ve used both consumer NAS (from 2 to 5 bays) and ZFS based appliances but I’m still searching for more performance.
In an enterprise environment there are a variety of solutions to these challenges – memory density is increasing (up to 512GB per blade in the latest UCS servers for example) and on the storage front SSDs and flash memory have spurred innovations in the storage battle. In particular Fusion-IO have had great success with their flash memory devices which reduce the burden on shared storage while dramatically increasing performance. I was after something similar but without the budget.
When I built my newest home lab server, the vHydra I used a dual socket motherboard to maximise the possible RAM (up to 256GB RAM) and used local SSDs to supplement my shared storage. This has allowed me to solve the two issues above – I have a single server which can host a larger number of VMs with minimal reliance on my shared storage. The concepts are the same as solutions like Fusion-IO aim to do in production environments but mine isn’t particularly scalable. In fact it doesn’t really scale at all – I’ll have to revert to centralised storage if I buy more servers. Nor does it have any resilience – the ESXi server itself isn’t clustered and the storage is a single point of failure as there’s no RAID. It is cheap however, and for lab testing I can live with those compromises. None of this is vaguely new of course – Simon Gallagher’s vTardis has been using these same concepts to provide excellent lab solutions for years. Is this really a poor man’s Fusion-IO? There’s nothing like the peformance and nothing like the budget but the objectives are the same but to be honest it’s probably a slightly trolling blog title. I won’t do it again. Promise!
If you’re thinking of building a home lab from scratch consider buying a single large server with local SSD storage instead of multiple smaller servers with shared storage. You can always scale out later or wait for Ceph or HDFS to elimate the need for centralised storage at all…
Tip: It’s worth bearing in mind the 32GB limit on the free version of ESXi – unless you’re a vExpert or they reinstate the VMTN subscription you’ll be stuck with 60 day eval editions if you go above 32GB (or buying a licence!).
This is the blog of Edward Grigson, an IT professional with a keen interest in virtualisation and storage.
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These rants and raves are solely my opinion and do not reflect the opinions of my employers.
Any of my code, configuration references, or suggestions should be researched and verified in a lab environment before attempting in a production environment.
Agreement to use any of my code or recommendations removes me from any liability as such....and I shamelessly stole this disclaimer from Jase McCarty's site!
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