StarWind: SAN Made Simple

So right after he finished explaining to me that he really couldn’t take the time to evaluate StarWind’s products, the Ur-Guru went ahead and did it anyway. And here’s what he had to say about them. There are a lot of technical terms in this post, partly because it’s about enterprise software, and partly because enterprise software products are more complex and partly because the author is (though he won’t admit it) a geek.

As I said in the call for reviewers, StarWind’s products are suitable for businesses with multiple PCs and a network who want to store (and back up) their data in a central location. ISCSI is just a technology that lets your computer talk to disks over the network the way it would if they were installed in your system, but if you want more details, follow the links to the Wikipedia definitions.

And if you have no interest at all in enterprise products—even for smaller enterprises—skip this and wait until next week, when I’ll be talking about something friendlier to ordinary humans.

StarWind Software approached Sallie about writing a review about their products and guess who got to play around with it instead? Yep, me, the guy known as Ur-Guru. Why? Oh, because I happen to have some servers sitting around that would make a good SAN.

Before I continue I have to say that even though my home office comes close to what you might find in a small enterprise or rack server I have very little need for a SAN (Storage Area Network), because every single system is already loaded up with many terabytes of fast RAID storage. A SAN, regardless of the size, speed, and cost, would always be slower than the local storage of each system.

However, if I wanted to centralize the storage for the systems in the network, whereby the systems themselves were smaller, less top-heavy computers, I would certainly be looking at something like StarWind Server or StarWind Enterprise Server (probably the latter because I like the replication features).

Also, if I were to overhaul the way my virtual machines are managed and stored throughout my network, and if I wanted to create a single cluster of systems to run that, StarWind would certainly get an even closer look.

So what is StarWind Server, you might ask. If you’ve familiarized yourself with the concept of a SAN, the short version of the story is that StarWind Server is a software product that turns a Windows 2003 or Windows 2008 server into a fully capable iSCSI SAN system.

Think of it as having storage space on your system that isn’t local but remote and runs over a network. I could get into how to build a complete SAN network and recommend fiber-channel switches and how to hook it all up for the best performance and manageability but I’m going to restrain myself and focus on how a more modest SAN setup could be of use for the “power user” or small business.

What I tested was a combination of StarWind Server combined with the Starport iSCSI Initiator and AoE Initiator. Lots of terms you may have never heard, but in essence, Starport contains the drivers required for a system to use iSCSI over the network in order to use storage space on the StarWind Server SAN by connecting to it and making it appear as if the storage is a device or disk connected to your computer. In technical terms it is connected, except it’s connected over the network.

Installation

Installing the StarWind Server was a breeze, especially since it’s a very small installation with a very modest memory footprint. After installation I connected to the local system via the StarWind Management Console (the application that allows you to configure your SAN) and created an Image File Device of 800GB on one of the arrays on the system I installed it on. If you must know, the system I used for testing is a Dual Xeon E5472 with 32GB of RAM and 6.4 Terabyte of RAID-5 storage split over eight 300GB Seagate Cheetah HDDs and four 1000GB Samsung Spinpoint HDDs, running 64-bit Microsoft Windows Server 2008 SP2 (that’s SP2, not R2). StarWind Server (and the Starport) support both 64-bit and 32-bit systems, of course.

When specifying an Image File device it complained that I didn’t give it the right file extension (*.img). I think the developers at StarWind might have to look at this and add a few lines of code that will automatically add the extension if the user forgets to add it. It’s the small things that matter when it comes to having a smooth end-user experience. The Image File Device created on the StarWind server is really just a large file that has the size you specified when creating it. So what StarWind Server does is, while running on top of Windows Server and its regular file system, create large files to actually store the data.

Because I never install anything relating to drivers for testing purposes on systems I use for my daily work I decided to give the Starport software a try by installing it on a virtual machine (VM, for short) that ran on one of my workstations. Again the installation was a breeze and the memory footprint of the StarPort iSCSI initiator is very small. I’m glad to see some companies still care about writing efficient software that isn’t bloated to the point where you wonder what’s bigger, the OS or the application running on it. The VM I used had a local pre-allocated disk of 80GB and was assigned 4GB of memory, running Windows 7 64-bit. (I’m not even sure if StarWind supports Windows 7 at this stage but I didn’t run into any major problems seeing as how most Vista x64 drivers will run fine in Windows 7 x64 anyway).

After specifying the license to use for Starport I added a Remote iSCSI Device to is via its management console, gave it the name (or IP address) of the server that was running the StarWind Server and it immediately connected me to the Image File Device I created there. Next up, I opened up the Computer Management on the VM, headed for Disk Management, and saw “Disk 1” in there which was in fact the Image File Device on the remote server. From there on it’s a piece of cake, you partition and format the volume the way you need to and voila, you’ve got yourself a bunch of storage that looks like it’s local to the system but is really running elsewhere over the network. Smooth! I now had an F:\ drive on the VM.

Performance

Of course the real test for a SAN would be to see how it performs when you start throwing things at it. In this case, a lot of files of varying sizes.

I’m pleased to see the performance was quite spectacular. The network in my home office is all 1Gbit running through a solid HP Procurve 24 port switch using jumbo frames. Copying data to the new F:\ drive was fast. On average I got around 65MB/s with peaks on the larger files of 90MB/s. To compare, these are very acceptable given that SMB2 copies (when you copy files from one system to another over the network via Windows Server 2008 and Vista/W7 systems) usually runs around the same for files of varying sizes with peaks of over 100MB/s for larger files.

Clearly, there is not much of a bottleneck with StarWind Server and I’ve seen SAN setups that perform so poorly that you’d wonder why so much money was thrown at it when it performs that badly. Having said that, there was a noticeable hit on the performance I normally have between the systems but for one, I was running tests through a VM and secondly the data is being written to an Image File Device which, of course, comes with a bit of overhead.

By now some of you might be thinking “OK, I understood half of what you’re on about so what would I want all this for?” Well, that depends whether you may have a need for SAN or whether sharing files between systems via a NAS is sufficient for your needs. SAN and NAS are often confused, even though both serve more specific purposes that the other doesn’t. I’m more a NAS guy than a SAN guy depending on the situation and the setup.

I would really prefer a SAN configuration (over NAS) if I were building a set of servers that are virtualized and centralized in a rack. Either to have the SAN provide storage to the VM’s or act as the storage for the VMs.

StarWind also offers a free version of their software, which comes with limitations (like a max. 2TB storage size) but should give you something to look at and give a try without having to overhaul your entire network and jump in off the deep end into the world of SAN. However, the Server and Enterprise Server versions offer more than just basic Image File storage and include support for a RAM Drive Device. If you have a really large server with a good deal of RAM you could designate some of that RAM as storage space.

The performance of that is hundreds, if not thousands of times faster than disk based storage. But RAM comes at a higher cost and I wouldn’t recommend using RAM disks for actual storage unless you have redundancy in the system and can deal with situations where a server might blow up, break down, or simply stops working for any of a million temporary or catastrophic reasons. In addition other device types are also supported like Virtual DVD devices, Disk Bridges (where your storage/partitions on the server are actual volumes/drives), SPTI devices (which allow any physical storage device, including DVD, tape, etc. to be used as iSCSI targets that your client machines can connect to), Virtual Tape device (which emulates a tape drive while using disk based storage via StarWind VTL). There’s quite a few options there that make StarWind Server a very interesting choice when creating a SAN on your network.

But as always, just like RAID IS NOT BACKUP (it is redundancy) don’t mistake SAN for a way to back up important files if all you rely on is the continuous operation and solidity of the SAN. As always, you have to ensure you have backups and that’s where my favorite feature of StarWind Enterprise Server comes into the mix; it allows two SAN servers to replicate data, much the same as a RAID1 mirror. Except, of course, the mirroring happens between two physical SAN servers instead of all on the same single hardware box. This is most definitely something that shouldn’t be overlooked when building a SAN.

Another good-to-have feature in StarWind Enterprise Server is the Snapshot and CDP (Continuous Data Protection) Device which allows you to create virtual drives that support backing up and snapshots (taking a backup of a certain state at a certain point in time).

The good…

To conclude, my experience installing and using the StarWind Server and Starport has been a good one. These aren’t the kind of scary server applications that come with a ton of overhead and require a study of many days to get a grip on the configuration. The management console windows to configure both the server and client side are well laid out, simple to understand, and offer exactly what you need without a huge amount of complicating factors. If you’re looking for a SAN without the headache, I think Starwind certainly has what you need.

The bad…

The only bad thing is that I didn’t get to use StarWind Server in daily production use, mostly because it would be a step backward for me in terms of storage and performance and what I really would have liked to test this on would have been a system with 50+ client systems with two mirrored SANs using CDP over a 10Gbit fiber-channel network. Alas, I don’t have any of that sitting around here to toy with. If I had, however, I’d probably go back to StarWind and see if I could get a good deal on promoting their software by showing how it operates in my home office. 🙂

And now it’s back to my adventures in WordPress, with a reminder to everyone to upgrade in a timely fashion: there’s a nasty worm going around that attacks popular content management systems like WordPress and Joomla.