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What NAS To Buy?
An anonymous reader writes "Currently, I'm running an old 4u Linux server for my private backup and storage needs. I could add new drives, but it's just way too bulky (and only IDE). For the sake of size and power efficiency I think about replacing it with a NAS solution, but cannot decide which one to get. The only requirements I have are capacity (>1.5TB) and RAID5. Samba/FTP/USB is enough. Since manufacturers always claim their system to be the best, I'd like to hear some suggestions from you Slashdot readers."
As a person who's suffered a RAID-5 failure and dealt with the poor performance I can say that RAID-10 is significantly better performance and significantly better reliability that is well worth it.
Don't make the RAID-5 mistake.
The price difference may disappear quickly with the difference in power usage.
According to my Kill-A-Watt, my old NAS box (old P4 desktop with two 750 gig SATA drives) costs me almost $20 a month in electricity more than those two drives in a USB enclosure hanging off my Airport Extreme.
When I was using a rack-mount HP server, it was costing me twice that!
Let me say this, as someone who runs a small network which has something like 10TB of total storage, don't use a NAS device if you want anything more complex than a samba server with (probably) no security. Use a server with either attached storage, internal storage, or SAN storage.
NAS devices suck. Either that administration is tedious and incomplete or nearly nonexistent.
Are you hoping that your NFS permissions work right? They won't, at least without massive configuration on your part. Are you relying on the data always being available? It won't be, because even the semi-expensive ones use junk hardware. Wanting high availability solutions? Don't even think about a NAS device. Most of them don't have hot-swappable power supplies, hard drives, or anything else.
They're essentially toys, overpriced, underpowered, hard to configure toys that break far too often.
Use a dedicated fileserver. Do yourself a favor. I've got 2 snap machines (one with expanded storage), an IOMega StorCenter, and they're all crap. The other one's I've investigated are crap. Use a real machine.
Check out my sysadmin blog!
At one time I got myself a brand new $200 P4 (back when it was still the best chip) at a grand opening of an Office max, plugged in a whole pile of drives and set up a software raid 10.
Then I did the math. the power bills to run this thing 24/7 were going to be more than the cost of the computer. My disks would be pretty much spinning all the time even though for home usage i'd say I actually hit non-local disks maybe a few times a week at most.
So I sold it and went to external (firewire) disks and attatched them to computers I was already using. This makes so much more sense as a backup system. It actually cost less both in terms of chassis and power for a small system.
Even better is that I can detach the disks and take them offsite (my office desk at work) and rotate in new disks. my big fear is not losing my last week of stuff but losing say all my family photos or long term bussiness records, manuscripts etc. So really an always-on raid is not as big an issue to me as off-site storage. Because I rotate the disks I still have duplicates of everything.
The other nice thing is that since I have a wireless G network, when I want fast access to the disks I can move them from my desktop to my lap top.
Now some people say well, those external disks are more expensive because of their chasis and interfaces or that they are slower. But not really. with the dedicated server solution you have the computer and interface cards to buy. Probably a separate screen and keyboard as well. The power consumed is far more. And for low duty cycle usage you don't have to spin the disks all the time.
Some drink at the fountain of knowledge. Others just gargle.
As a person who's suffered a RAID-5 failure and dealt with the poor performance I can say that RAID-10 is significantly
better performance and significantly better reliability that is well worth it.
RAID is just a reliability mechanism. It's not backups. Any NAS solution you look at should have a way to back up part of it, and many do.
RAID5 is acceptable IF you regularly scrub the array AND you don't have too many devices in the RAID set, because it is designed to tolerate one disk failure. RAID6 in a 4-5 drive configuration should be plenty safe in quantities most people would use for home NAS's.
RAID10 does offer much better performance, but the performance increase would be largely wasted in the home market. If you're watching video, anything over a couple megabytes a second just helps with seek performance (802.11N is just about perfect for most movie and TV "rips", for example- 802.11g is doable), and when you're uploading or downloading media, anything beyond the speed of local disk is also pointless.
Please help metamoderate.
DO NOT get a SATA card, unless you're putting it on a very fast (high speed) bus. A regular PCI bus is too slow.
I've found that MOBO's with SATA Raid on board are better performing and cheaper than separate MOBO and PCIe SATA Raid, but there are features on the PCIe SATA RAID controllers that many people might want.
ASUS makes a couple of MOBOs with SATA RAID, that I've found very good. I really like the NVIDIA SATA RAID setup on this board. Though you may be able to find a similar board cheaper somewhere else.
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
Problem with Openfiler is it doesn't do any authentication itself. Or it didn't the last time I messed with it. You had to have another machine set up to do LDAP or Samba (or whatever) authentication. It was a huge pain in the ass and I gave up on it as a home-based solution. Very powerful, but huge overkill.
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