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SAN, NAS, Cost and Benefits?
luetin asks: "Our company is at the point where our storage and backup infrastructure is ok, but not for much longer.
We are looking into SAN, NAS, and
variations
thereof. We are a small IT department, with two sysadmins and two programmers. Right now we have stored/circulating about 2TB of data, and that's going to increase steadily in coming years.
Does Slashdot have experience setting up SANs? Tales of costs and benefits of SANs versus a gaggle of NAS? Can SAN be implemented by reasonably seasoned IT people, or is it too dark an art?"
You should consider automation for managing your storage deployment. It eliminates error-prone manual steps but still gives you the control you want as a storage administrator.
There are some new players in this area, such as Invio. I think its worth checking out, especially for a new deployment.
Used Netapp brand Network Appliances
We used to use Netapps at MindSpring to serve 80,000+ commercial webhosting clients. They are tough as hell, easy to maintain, last forever, and do everything right. You can mount the shares with NFS or CIFS. It has a web based interface for configuration, or a simple command line interface. You can add drives and change volume sizes, inodes, etc without shutting it off or losing a connection to it. The snapshot feature will eventually save your butt like it saved mine on many occasions. Hope this helps.
For every annoying gentoo user, are three even more annoying anti-gentoo crybabies. Take Yosh from #Gimp for example.
You're on the extremely low end of where a SAN becomes practical... and it may not be practical in your environment. If the SAN is really going to stretch your budget thin, don't do it!
Xiotech's products are very easy to use, but costly. You'd be lucky if you could get the whole setup for under 80,000 USD. The SAN hardware itself is reasonably priced, but you pay a license to use 1-8 servers, you pay more for 9-16, and so on. The software part gets expensive quick. Also, be aware that Xiotech charges about three times the off-the-shelf price for drives and they won't let you use off-the-shelf drives or you void your warranty and get no support. They certainly make their money on the drives.
HP/Compaq has the EVA series of disk arrays that use very similar "virtual array" technology that Xiotech uses. Again, very flexible, but expensive. At least HP doesn't make you pay more to connect more servers and the charges for drives is a little more reasonable.
It certainly seems that someone along the way forgot that RAID means Redundant Array of Inexpensive Disks. The whole point is to make a bunch of relatively unreliable disks into a very reliable whole, unless you just want speed and don't need the reliability.
If you're thinking about a two or three server cluster and just need shared storage where you can add more drives, you might look at some of the small and inexpensive rackmount IDE RAID solutions that are available with Fibre Channel and a FC hub, but be sure to get references and see who's using the things and what their experience has been. You can get two terabytes for under 15,000, but some of these are good yet inexpensive and some of them are just cheap junk.
These IDE RAID solutions do not provide the advanced features of a virtualized SAN, like changing RAID types on the fly (from RAID 5 to RAID 10, for example). However, you could easily spend 60,000+ on a Xiotech SAN or you could spend the same amount and have eight terabytes in four IDE RAID modules. Your choice, but for a small shop, I say get the eight terabytes and setup mirroring across two of these RAID boxes.
Ouch! The truth hurts!
Well I would start with staying away from Compaq (now HP) SAN products. I was on the QA team for their SAN it was the worst software I have ever encountered in my 15 years as an engineer. Total crap.
The machines are pretty good at what they do though, but the software and support licenses are fairly high.
We use our SAN extensively. Most of our HP-UX systems have the preponderance of their disks on it. A number of Windows systems do the same. However, the configuration and support of our HP XP disk systems is compex and expensive. In power alone, they have steep requirements.
But, we have technical needs that require consolidated storage. It's not for the understaffed or underfunded (we're on the edge of being both, too). It is a hassle, and it's difficult to do without a healthy support contract from your disk subsystem vendor. Also, cheaper second-market devices don't get supported without a big "recertification" fee to the vendor.
But, how much of that 2TB needs to be online? Can it be on 9.99 uptime systems? Can it be near-line? Does it need to be copied offsite for DR? Depending on those answers, you might be very happy with devices like the ones Raidzone sells (not an endorsement since I have no hands-on with them).
On the other hand, a NAS device with a reasonably affordable fast or gigabit ethernet (my network gurus assure me that those are two separate things... I think they might be high) backbone could allow iSCSI, NFS or CIFS mounting with no issue. In addition, you might be just as happy to have the device serve its own files rather than be mounted by other servers. It depends on what the data needs to do.
The only big caveat is to find something structured around what you need to do with the data, and buy two or three of them. Even if redundancy isn't simple or obvious, you'll find a way to do it eventually. And you'll be much happier that you did.
Amateurs discuss tactics. Professionals discuss logistics.
I've been out of the SAN buisness for a year or two now. Back them standards was a big thing, and some of the big names didn't interoperate well with anyone else. Ask the standards question, and don't buy anything until you have an answer you like.
That doesn't mean you have to go with standard gear, but know what you are getting if you don't. Don't buy an old brocade switch for example, because it won't work (without upgrades which may or may not exist) with anything but brocade switches. Likewise EMC isn't standard one all points, but they make some popular gear for a reason. It may or may not be worth the expense. (I'd say no, but I worked for their competitor)