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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."
Something such as FreeNAS (http://www.freenas.org/) may work for you, if you purchase your own hardware. A quick rundown of what it provides: http://en.wikipedia.org/wiki/FreeNAS
I've got the WD MyBook WE 2 TB drive a few weeks ago. I haven't installed any of the MioNet software on my computer because I heard complaints about it. I've got it set up in RAID 1 mode (mode 5 needs a lot more drives). Performance is good so far. Powere consumption is around 20W, as opposed to a desktop PC at around 150W. Since it's running OpenLinux, I was able to add SSH and do more configuration of the SMB server this way. The linux partition is 2 GB; the Arm processor is somewhat underpowered for most other applications.
Using Solaris Express with ZFS. There is an extensive set of articles on how to do this at Simon's blog http://breden.org.uk/
Since you didn't really say much about other requirements, I'll recommend the NV+. I just got one on ebay and it's awesome. It just works. Shows up on the network immediately, has lots of blinking lights and a nice web config interface. 4 bays expand up to 4TB. Plus, it's a shoebox and not a gigantic 4U rack.
http://www.drobo.com/ Automatic RAID, hot-swappable and you can use any type/size/configuration of SATA drives. Upgrade as the price of drives go down. I've been using one for two months now and am very happy with it. I can watch a streaming movie while I yank out an 80GB to replace with a 500GB, and the movie doesn't even stutter once.
Get a d-link DNS323 and toss in 2x1TB drives, and you are set.
The firmware hasn't really matured until now, with FTP/iTunes/samba server, and the latest addition is a torrent client, for all your 24/7 downloading needs.
It's quite hackable, with an USB port for printer sharing, or storage with a bit of hacking.
I had horrible firmware problems the first ½ year i had it, but now it's smooth sailing
I've been using an old desktop with large HDs for years, always looking for that perfect, small NAS with minimal RAID that I could put in a corner. Unfortunately I was always frustrated since the majrotity of units were directed at business and ran over $1k (that's just too much to pay when a desktop is so cheap).
However, recently there has been a real surge in the market, with a number of more home directed products available. These often include streaming services, in some instances are OSS friendly or even hackable, and have small form factors with RAID1 or RAID5.
The best reviews I've found are at SmallNetBuilder.com... very thorough, always show the boards, etc. The best units I've found (or at least the ones that look the most interesting for my needs) are the following:
Synology DS207+
Looks like a great unit, with lots of control over the drives (RAID0, RAID1, and other drive configurations). However, it's a little pricey for a BYOD NAS ($350+). The support for NFS in external USB drives is nice, and the reviews are excellent. The fact that it doesn't have slimserver support (or not natively) is another weakness... I've been eyeing adding a squeezebox or other player to my stereo, and would like the option. One thing I can't figure out... is it worth going with the "+" unit, or is the old 207 adequate? It's a lot cheaper...
Netgear ReadyNAS Duo
This is obviously the most expensive option, and is about on par with the Synology unit from a performance perspective. I like the fact that it has Slimserver as a native option... seems very well rounded. Also has internal NFS support, which both the other units lacked. Negative seems to the weak photo sharing app (requiring a local install) and the lack of drive controls (RAIDX being the only option). The fact that the 1TB unit costs $600+ also sucks (that's with just 1 1tb drive)... I want a 1 terabyte x2 setup, and I can get a nice 1TB drive for a hell of a lot less than the $275+ (that's the difference between the 500gb and 1tb versions of this sucker). Basically means the 1 drive is a throw-away for me, which I have a hard time swallowing...
Hard choice to make... but I think I'm going to go with the Synology and two 1tb WD caviar drives I can get for $160. Total cost around $650... a little more than I wanted to spend, but this should be good for years to come.
-rt
I don't know why AC got modded troll... it's good advice. I built my file server as raid5 and am regretting it. It's the most economical, and you do get some redundancy.. but if I had to do it all over again, I'd totally go raid10.
With Raid5 .. two drives fail and your done. Unless you buy every drive at a different time from a different manufacturer, chances are under the same wear conditions, two will fail around the same time. With a raid10 .. you put all one brand on one side, all of another brand on the other side... possibly on a separate controller. Raid10 can withstand a much larger failure... and you also get some serious performance++.
To reply directly to your reqs (kind of lost track of the thread there) both manfacturers have other versions of those drives that are RAID5 (the NV+ line from Netgear, other Synology units).
As for services, both can be used as FTP servers, web servers, or anything else (I think both are LAMP, I know the Synology is). The Syn unit also supports bittorrent natively.
-rt
Netgear's ReadyNAS line of products (originally made by a small outfit called Infrant before Netgear bought them out) strikes the best mix of NAS characteristics outside of rolling your own.
The RND4000 retails for $900 diskless, although you can occasionally find it a bit cheaper. It has four SATA inputs and uses a "drive cage"-style design to eliminate wires and allow for hot-swap; it's 9" x 8" x 5". It has gigabit ethernet interface and 3 USB ports. You can set it up as a print server, interface to a UPS, set it up to auto-copy out to a USB HDD on a particular schedule, or set it to auto-copy in from USB flash card/drive to a particular partition.
All the interface is web-based, and in addition to the usual NAS features it supports FTP and HTTP sharing of files, Active directory integration (if that floats your boat), user quotas, and other fun little stuff. The system supports automatic power-on and -off at scheduled times, a journaled file system, and spin-down of drives when not in use. My model states that it uses 60W spun down and 130W at full tilt.
It supports RAID-5 and a RAID 5-based system that Netgear/Infrant call X-RAID. X-RAID allows for dynamic expansion of capacity, which is a very nice selling point in a NAS box. Got 4x250GB drives and want to upgrade to 4x750GB? Just pull one drive at a time, wait for rebuild, and repeat until all four have been replaced. Netgear/Infrant has never gone into the specifics of how it's done, but I'm guessing the drives are partitioned and the partitions are then RAIDed to ensure drive-level failure can't cause a problem. I know I've seen people do the same thing in software on x86 machines (in LVM, maybe?), so I'd guess that's what they're up to.
I have an older Infrant ReadyNAS (the X6 ver. 2 model), and have been very pleased with it. I have heard grumbling that after the Netgear buyout the support channels have gotten a little more irritating. I haven't personally had to deal with it, so I can't vouch either way, but I do notice that the latest system update (which had been in beta a few months ago when I checked) is now listed as a proper release on their downloads section, so they appear to be maintaining the normal release schedule.
You will hear some /.ers recommend rolling your own, and they'll definitely have good arguments. $900 diskless goes a long way in small, quiet, cool PC gear. If you want a NAS system, though, I've found this to be one of the best mixes of features (particularly the dynamic expansion) available short of a full-on PC.
I used to set up my own linux fileservers... then someone else asked me to do one for them, then someone else... and so on.
So I bought a couple of the Buffalo NAS TeraStations. Slightly pricier, but worth their weight in gold for 5 second configuration.
And it should be noted there are still plenty of IDE drives out there in the larger sizes. If you really want to go with SATA, then get an adapter card.
Lack of performance? Not an issue, since I've yet to see a NAS that- at the lower end pricewise- was competitive in this regard, anyway.
Or, keep the server, and drop in a new $100 mobo/chip combo that allows for better power management. Regardless, I've found things are much better with a home server than they ever were with a NAS, and my DNS, DHCP, Samba all work better, plus I now can run squeezebox.
Having just seen terabyte drives at $169ish this past weekend, the flexibility of adding storage also makes it a better solution, too.
stored on computers from birth to the grave
With Raid5 .. two drives fail and your done
Then go with RAID 6. Takes 3 failures (out of 4!) to lose data. By the way, is there any sort of setup out there with more than 2 parity drives?
Also, if you've got 4 drives in your RAID 10 setup only two drives need to fail for you to be screwed, plus you only get (theoretically) twice the performance of a single drive, as with a RAID 5 setup for the same amount of drives you get 3 times the performance.
You just got troll'd!
See www.smallnetbuilder.com. They review NAS devices regularly. As well, they have a set of NAS charts with benchmarks.
I heard a lot of good from friends of mine about the Synology Cube Station CS407, and that's the one I have on order now. I like the fact it's expandable, I'm e.g. planning to run a Squeezebox server on it. It has good support, and a large user community.
Others I heard about: Intel SS4200-E (Helena Island). It exists in two versions, one with an embedded OS on a flash and one without any soft. The one with software included has not that much possibilities and is not expandable, it's in the category "it just works." For the other version, I heard installing Linux or Windows Home Server on it is a PITA...
The ReadyNAS by Infrant (recently bought by Netgear) also gets good comments.
Using RAID 1+0, you get almost 4 times the performance for reads, and 2 times for writes.
Using RAID5, you get maybe 3 times the performance for reads (if you're lucky), and writes can be slower than a single drive due to parity calculations.
Clearly, 1+0 is the preferred choice for performance (and yes, I have used both, for years)
I would still recommend RAID5, as it's worked quite well and been very economical for me, but performance-happy it is not.
Random and weird software I've written.
uhhhhh RAID6 will only support the loss of up to two drives....just like RAID10. RAID6 on the other hand doesn't use as many disks as RAID10.
Insert funny smart-ass comment here.
Just to add a bit of information to this post. I believe the RAID mode this poster is talking about is indeed RAID 10 and not RAID 1+0 or 0+1 -- stripped mirrors or mirrored stripes. This new RAID mode is supported by the linux md driver.
Linux MD RAID 10 driver page.
This RAID mode does not require an even number of discs. My understanding is that writes are much faster with RAID 10 than RAID 5 because parity checks are not necessary. However, this RAID10 mode gives you only half of your total RAID size, and RAID 5 gives you your total RAID size minus one drive in capacity.
Some useful, more detailed (and likely more accurate) information
Some performance comparison results to RAID 5. It would appear that the read performance is close to RAID 0, and the write performance is close to RAID 0 divided by two -- because every write has to be done twice. Furthermore, RAID10 can be more robust for drive failure.
I don't know why AC got modded troll... it's good advice. I built my file server as raid5 and am regretting it. It's the most economical, and you do get some redundancy.. but if I had to do it all over again, I'd totally go raid10.
With Raid5 .. two drives fail and your done. Unless you buy every drive at a different time from a different manufacturer, chances are under the same wear conditions, two will fail around the same time. With a raid10 .. you put all one brand on one side, all of another brand on the other side... possibly on a separate controller. Raid10 can withstand a much larger failure... and you also get some serious performance++.
My advice is that if you can't explain how raid5 will help you, then you most likely don't need it and should use raid10.
Those that really need raid5 can explain how it is more cost effective over a given time span for them than raid10.
Not to be pedantic, but RAID10 will only guarantee data security with one drive failure. With RAID 10, there's an approximately 1/3 chance that the second drive to fail will cause you to lose all your data.
Of course, with RAID6, any two drives can fail while ensuring the safety of your data. Hot spares are a good idea and will minimize the chances of having a three drive failure.
and not to be a tremoundous nit-picker, but for 100% true data protection you can't rely just on what type of RAID set you employe. A tested backup/restore process must be put in place, anything less and you risk data loss.
Insert funny smart-ass comment here.
RAID is just a reliability mechanism
No, it is not.
Repeat after me: RAID is for high availability, not high reliability.
If you want your data to always be available, you want backups, incremental backups, distributed chronologically and geographically.
If you want your data to be constantly be instantly available, then RAID is what you want. You still need backups to assure the data will always be available.
Interesting, but it's not a good solution for a household with multiple computers running at odd times. What if you're at work and your wife wants to access those mp3s? She has to turn your computer on? She has to take the firewire/USB drive from your computer, including the power cables and stuff?
I have a USB drive, with four people in my household, and five computers total, it's not a viable solution for sharing all the family photos and music. You may not need a dedicated server, but at least one box has to pretty much always be on.
If you skip down, you might see my other thread:
Online storage
I guess it depends how much you have to store, but the solution I was given sounds great...
The only downside is speed, but I don't see why people really need that much speed for most things. I mean, I don't normally, for example, rotate out ALL of my mp3s on my player, just maybe a few dozen at a time; low-res photos are on my website, so I don't normally need to access the high-res versions very often... plus I'd generally work locally and then save remotely.
So I haven't tried this out yet, but I intend to... for my 30GB worth of stuff that I have right now (that's worth backing up and sharing amongst the computers), it's like $4.50/month. Sadly, I wish I could use my GoDaddy account (where I have over 100GB free), but I can only use that with FTP. Fine for me, but no one else in my family.
Stupid sexy Flanders.
RAID10, is a mirror of RAID5 arrays.
RAID0+1, is a RAID5 of mirrors.
No. The old nomenclature (such as "RAID10") was never defined properly so different people used different definitions. One vendor's RAID10 can be the same as another vendor's RAID0/1 so be careful.
Since 1990 or thereabouts people have taken to using the plus symbol, so
RAID0+1 is a RAID1 of RAID0s (a single mirror)
RAID1+0 is a RAID0 of RAID1s (a bunch of mirrors)
RAID5+0 adds (or stripes) a bunch of RAID5 arrays together.
You notate the RAID levels in the order they were applied; if I take 96 disks and make 12 stripe sets (RAID0) and then make six mirror pairs (RAID1) and then make a RAID5 array from them, it would be a RAID0+1+5 array. The notation is infinitely extensible and simple to learn and remember.
One could build something similar to a NetApp for perhaps cheaper. A business shouldn't do a roll-your-own NAS and expose themselves to the what-if case of their admin dying or resigning... unless the budget absolutely dictates the cheapest solution as most home businesses do.
Yes and more. Don't let sticker shock completely rule NetApp out as a viable option. Take a look at the WAFL filesystem and other NetApp technology.
Instead of a NAS, I use two Antec 900 cases with low-end pc. Each case can hold up to 9 HD (if you don't need an internal DVD), and the disks are located in 3-disk containers with a dedicated 120mm fan (yep, one fan for every 3 disks!). There is also a huge 200mm fan on top of the case and a 120mm on back. With all those fans the disks stay cool no matter how badly you ride them, and the fans can be set at the minimum speed; there is not much noise. Also there is 2xUSB and 1xfirewire ports on top of the case, which I use for the O/S.
So in a single case (which is also quite the looker) you can get 9x500GB or even 9x1TB. Of course you need to find a mobo with enough SATA (or IDE if you prefer) connectors, but 2x SATA RAID 1 cards are cheap and reliable. And you also need a good PSU (I live and die by Antec!).
I don't know where you live, but here in Canada this whole setup is quite cheap:
-mobo+cpu+2GB DDR2: 225$
-psu: 100$
-SATA RAID cards (2): 50$
-Antec 900: 125$
-9x500GB HDs: 800$
-USB stick (for the O/S): 20$
So for less than 1500$ you get a 2.2TB fully redundant storage, on which you can connect using Samba, NFS or whatever protocol your Linux O/S supports. As for myself, I use iSCSI and LVM in my client PC to connect to my 2 Antec servers so my system is completely redundant.
The only tricky part is to access the RAID cards from Linux, but even with no-name brands you can make it work with stock drivers and a good search engine...
lucm, indeed.
No, Samba doesn't have a 2GB file limit. Samba is fully 64-bit clean.
Jeremy.
I would still recommend RAID5, as it's worked quite well and been very economical for me, but performance-happy it is not.
I'd recommend RAID6, personally. Not because two simultaneous disk failures are likely -- they're not -- but because the process of rebuilding a degraded array is very intensive and there's a good chance that if you've got a second drive that's getting close to failing, the rebuild process will trigger it.
This happened to me. Twice. I had a six-disk set, five active disks in a RAID 5 plus a hot spare. One drive dropped out and put the array in degraded mode, so the hot spare was brought in and the rebuild process started. Halfway through the rebuild, another drive failed, and obviously the whole array went with it.
The second failure was transient, so after rebooting I had five functioning disks, but the array was hosed. Thanks to the e-mails mdadm had sent me during the failure and rebuild, I knew the EXACT order that the disks were in prior to the start of the rebuild. I forcibly reconstructed the array from scratch, telling MD to treat the array as being in a valid degraded state no matter what the superblock said.
The transient failure happened again during the second rebuild attempt.
Since I didn't have backups of some of the data on the array, I crossed my fingers and tried again. This time it worked. I immediately dropped in a new drive, forced a failure on the one that had failed twice and breathed a profound sigh of relief when the rebuild completed successfully and my data all appeared to be intact.
I decided then that RAID6 is a hugely superior solution over RAID5+hot spare, because a RAID6 array will survive a second failure while rebuilding the array onto a fresh drive.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
Yes, a faulty controller could potentially corrupt the RAID, but major data loss shouldn't happen with RAID5; the checksums would fail on the next read.
Worse:
If a hardware raid5 controller dies, you have to replace it with one exactly the same (or very compatible), or you never see your data again. Each vendor uses different checksum methods, etc.
If you use software raid, you don't have to worry about the controller, or even the motherboard dying; you can put the drives into any computer which can run the same software (OS), and read/write no prob.
Nothing to see here; Move along.