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Just a short post to wish everyone the best wishes 🙂

Thanks to everyone who visited my blog site in 2011!

Is this blogpost going to inspire you to buy a soldering iron and build a PCI-e card? No. Is it a really cool idea to try and build a Fusion-I/O or EMC Lightning-like card in your homelab? Possibly: YES!

So what are Fusion-I/O or EMC Lighting solutions all about?

The idea behind server-side cards like these are really simple: You somehow get the cards inbetween the storage datastreams of the vSphere5 server, and you cache any data passing through on flash memory placed on the card. Some cards are smarter, some a little less smarter in the way they work. The basic idea remains the same though.

Doing read caching is not too complex for cards like these; there is no risk here in loosing data since you are only caching blocks from the array (which you then do NOT have to get from the array and this is where you win for reads). Can you also do write caching in these cards? You sure could, if you can live with potential data loss if the write was stored in the card and not yet synced to the array and your box burns down.


So how to build one of these without a soldering iron?

If you look at these server cards, and you take a step back, what do you see? Exactly, it is an appliance that has data in, data out and some solid state device on the side to cache stuff.

So what would happen if I built a virtual appliance, that uses NFS exports as an input and delivers NFS exports out again, using either memory and/or a local SSD drive as its caching device? By the sounds of this it could REALLY work. The best part? Your original NFS store would not be touched if you just did read caching. Write caching within this appliance would even be possible, especially when an SSD is used as a caching device (because the SSD would be non-volatile).

One major downdise of this solution would be the ineffectiveness of vMotion. vMotion would work, but if you want REAL performance you’d want to keep the VMs running through an appliance like this local to the appliance itself (to keep the NFS exports coming out of the appliance from traversing the physical network). A script might be able to vMotion the VMs to “their” vSphere server, or you could create a DRS rule to keep the VMs running off an appliance together with the appliance if the appliance only uses vSphere memory for its caching. Either way, this could work smooth!


So how to shape this idea

Instead of building my own appliance, I decided to look around for an appliance that already does this. After looking around for some time, I came to the conclusion that this has NOT been done yet. I could not find a single virtual appliance that would take one or more NFS exports and redeliver them from a local NFS server transparantly.

The thing that comes closest to this I think will be a ZFS-based appliance: ZFS is able to use memory as cache, and on top of that you can assign a “caching device” to ZFS as well.

Unfortunately it will not create a “transparant” appliance; the data on the external NAS (through a vmdk) or SAN device will be ZFS formatted. To bad, but at least it will be able to demonstrate the power of a software solution like this.


To the lab!

I will be testing this setup with some kind of ZFS-based NFS virtual appliance that will take caching memory or a caching device. I will be looking at appliances like Nexanta to do some fun testing! I’ll need an SSD in one of my homelab servers though, and most important…. I’ll need TIME.

Ask any user of a SAN if cache matter. Cache DOES matter. Cache is King! But apart from being “just” something that can handle your bursty workloads, there is another advantage some vendors offer when you have plenty of cache. It is all in the implementation, but the smarter vendors out there will save you significant overhead when you use RAID5 or RAID6, especially in a write-intensive environment.

Recall on RAID

Flashback to a post way back: Throughput part 2: RAID types and segment sizes. Here you can read all about RAID types and their pros and cons. For now we focus on RAID5 and RAID6: These RAID types are the most space efficient ones, but they have a rather big impact on small random writes. Read the rest of this entry »

Once shared storage came about, people have been designing these storages so that you would not have to care again for failing disks; shared storage is built to cope with this. Shared storage is also able to deliver more performance; by leveraging multiple hard disks storage arrays managed to deliver a lot of storage performance. Right until the SSDs came around, the main and only way of storing data was using hard disks. These hard disks have their own set of “issues”, and it is really funny to see how different vendors choose different roads to solve the same problem.

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Still had this coupon lying around for a free VCP510 exam. I got it because I did the VCP4-DT exam, and last week I saw that it was valid through… The end of THIS month. So what to do? I just took the shot. I hardly had any time to study, but then… That is nothing new to me… Just how I passed my VCP4 and VCP4-DT certifications as well 🙂

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More and more cool videos are getting round that explain certain things around virtualization, cloud computing and storage better and better. I thought I’d sum up my personal favorites in a blogpost.

Older stuff: The Internet

A very old but still fun to watch is “Warriors of the Net”. This video explains how the internet works. Things like packets, firewalls and routers are explained here:

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I heard a lot of different visions on the quality of the party of this years VMworld in Copenhagen. It seems that depending on where you were at the party, the quality differed a lot 🙂

I have been shooting some pictures along the dancefloor just in front of the stage… And it rocked!

Whats Hot, Whats Not

A picture says a thousand words. Or in this case, two pictures:

     Whats Hot…                                                                           …And VMware, really??? What’s Not.

Clearly, there were “some” differentiators this year round… Catching ducks in a pond without shotguns… VMware, REALLY???

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It’s tuesday afternoon, and the sessions start to die out. Everyone is getting ready for Steve Herrods keynote. What’s new? What’s new since VMworld 2011 Vegas?

For a report on Steve’s keynote from Vegas this year, check out Steve Herrods VMworld Keynote Summary blogpost I did. So what IS new? Read about it right here! Read the rest of this entry »

For the past few weeks EMC, VMware and the Dutch VMUG have been planning this: Free T-shirts for all dutch visitors of VMworld!

We printed 200 shirts, I think they came out very nice! I have the honor to show the first sneak-preview of the shirts:

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This post is the continuation of Under the Covers with Miss Alignment: I keep hearing this rumor more and more often: It appears that both snapshots and linked clones on vSphere 4.x and 5.0 are misaligned. Not having had the time to actually put this to the test, I thought it would at least be informative to give you some more down-and-dirty information on the subject.

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