Swatting up on SANFly...

Waiter waiter, there is a fly in my SAN!

SANFly, the pesky little SAN from emboot inc.

 

 (Fly 1, firewall 0 - SANFly could in future help segregate iSCSI across security zones)

I've never liked flies. One flew into the test lab the other day, and was determined to loiter on a CAT5 plug that had previously been involved in a rather unfortunate orange juice / sneezing fit from the previous week. Actually, one of my party tricks is 'fly flicking'. With a very steady, ultra-slow moving hand, it's possible for me, coming in at just the right angle, to move in right behind the flys 'butt' and 'fly-flick' the winged maggot off in to deep space. After a brief moment of 'quite-a-bit-faster-than-normal' flight, the index finger propelled insect parabolas down onto the floor 'battle of Britain' style, and, Jim, seems dead. But such is the way that flies are built, that a few minutes later after a few fly twitches, up it hops, and it's back in business - itching to throw up on something new. You swat it away from your Chicken Chimichanga, and back he comes again, tracking traces of dog doo round the salty rim of your margarita.

They are small. They are fast. They are hardy. They don't know when to quit. Yes flies have the capability to be extremely annoying.

And so, I can only imagine that this must have been the primary motivation of emboots marketing department - on settling on a name for their new iSCSI SAN target product, SANFly. Certainly, we see some fly-like characteristics here - small, fast & hardy - and perhaps the folks that it will find it annoying - might just be the other SAN vendors?

But what is there for them to get annoyed about? On the face of it, this is a product seemingly confided to the test lab. Mark my word. If you are thinking of giving iSCSI a twirl in your business, and want to get something up and running extremely quick & dirty, then SANFly is the little tinker you should grab hold of. Great for 'test' setups, but what about 'live' environments? Common sense might dictate that after learning the ropes with SANFly, you'd pick an established enterprise iSCSI target solution to roll out across your enterprise to entrust your mission critical business data?

SANFly, however, is not all that it seems. The free version was indeed invented for the test lab - but the commercial version, still very much a bargain, has a revolutionary feature which we think will have other SAN vendors reaching for the RAID spray. This unique feature is SANFlys capability to operate in 'shared' iSCSI target mode.

If you've ever bought &run a SAN, you'll know that they enable scalable, centralized, fault tolerant storage - and at the same time, deliver maximum IO performance. In an ideal world, and with limitless IT spend, you would love to run everything off your SAN: Files, databases, backups, NAS stuff, email, the lot. However, the one downside with SAN is their typically 'scalable' licensing models, and also perhaps other more traditional limitations of physical space and power - you are always going to be looking at a rather high cost /GB. So for many, SAN space, is the equivalent of your penthouse apartment - the home for your 'Very Important Data', whilst Doris' reception workstation can slum it in the more 'affordable housing' of a single 250GB locally attached SATA hard disk.

Perhaps you have all your servers hooked up to a SAN, and you would also like to enjoy the same benefits of doing this to the desktop. Think of the mind boggling benefits of moving all the workstations in the office over. The energy savings of removing 1,000s of hard disks. The maintenance and man hours saved on fixing flakey failed SATA desktop hard disks. The cost / risk to business when binning old computers, and failing to scrub the hard disks properly. There are no good arguments for having desktop systems off the SAN, apart from the cost of the SAN storage itself. Your company may be able to 'SAN up' 20 servers, but 1,000 workstations? If each workstation needed a minimum of 20GB or storage for the OS boot and system files, squeezing 1,000 of these volumes on to your SAN, depending on how large your SAN was, might not add up. Some might say it was even a waste of valuable SAN space.

Well for EVERY other SAN product on the market - it might be. Not for our annoying little friend though.... this is a fly with a sting in the tail! Err... SANBee!

 (Your typical client / server  network, with desktop systems booting off local hard disks) 

Unique to SANFly, this 'shared' target feature is very exciting. Migrating from the very typical situation above, and for instance you had 1,000 workstations,  rather than all of these clients having their own disks with Windows volumes - SANFly connected clients could boot from just the one single OS volume. That's right, one single OS volume. SANFly manages diskless connections and strips out unique identities depending on the iSCSI initiator ID of the diskless client connecting to it. So if you were working from a target image which was a fresh Windows XP install, but then shared it for multiple client access, you would still enter your license keys into Windows for each diskless client - and as far as each client is concerned the OS looks just like a dedicated local install. In reality however, the same OS files common to all clients would be shared, so there is a massive saving on storage space. There is no duplication of data - which makes this a hugely storage efficient solution - and perfect for your high cost /GB SAN. Any transaction unique to that client is stored on SANFly, and assigned to that client. So for instance, copying a file to your Windows XP desktop, that file would be unique to your client, and as such, be saved in SANFlys target storage cache.

What about updating? Well - here's the other interesting part. You would log in to the installation from your own client - with the necessary permissions, and perform updates as per usual. When done, you commit the changes back to the 'master' source volume, after which point, all the clients connecting to this volume are instantly working with the updated OS. So one OS update feeds 1,000. Beauty!

SANFly is (of the time of writing) still at version 1.0 and as such, it may take a little more time for some extra functionality (being able to clone identities off to other targets for instance) to appear which will make the dream of moving everything in your organization over to SAN - a reality. We recommend monitoring SANFlys' development very closely, and we will be writing about new updates as and when they come along.

For instance, SANFly currently does not support clustering, as such - the server running SanFly would therefore represent a single point of failure - sort of a fly in the ointment. Perhaps hold off whipping out all the desktop hard disks just for now. That said, thanks to SanFlys small footprint and simplicity of installation, we have successfully installed SANFly on diskless servers (see diagram below) which themselves boot off enterprise SAN technology. This means that as the SANFly server's storage itself is clustered, the targets data & cache is far therefore also clustered. It's a little fly of a SAN running on top of a big elephant of a SAN. They both get on great.

 

There are all sorts of other benefits to running SAN on SAN, such as tightening up iSCSI security, increasing read caching to improve performance, ease of management, and of course all the other generic SAN benefits we mentioned earlier.

As for the name - perhaps 'Fly' was a little on the negative side we might have preferred something a little more exotic & with a bit more of a killer instinct - perhaps 'SANMantis'

And I wonder if they called the Beta version 'SANMaggot'?