Home Network Data Storage Device 649
It happened again- a machine on my home network died. Taking with it tons of data. It's mostly backed up. No huge loss. But I finally think it's time to get some sort of network raid disk. A unified place to safely store data accessible to the numerous machines on my home lan. So now I pose to Slashdot readers- what are your recommendations? I'm looking for something with RAID and SMB sharing. At least a quarter TB, probably a half, but with some room to grow. What have you used? What works? What fails?
The Poor Man's RAID Array (Score:5, Informative)
But for those of you with fewer fiscal resources, I will tell you the stories of my friend and me, a.k.a. The Master Rebaters.
My story is a simple one. I love music. I have over 1,000 CDs and have spent a lot of time meticulously ripping them with my friend CDex [sourceforge.net]. So, I have some 350-400GB of data that I would like to archive. There are a multitude of possibilities but, since I'm short on cash, I opted for a simple $13 RAID 1 controller [geeks.com]
My friend, however, opted for a huge and expensive RAID 6 array controller made by Promise. Then he waited and waited until there was a 250 GB Maxtor rebate at CompUSA [compusa.com] or Outpost [outpost.com] and went in and bought five with cash. Then he filled out the rebates for relatives and played the waiting game. Huge initial investment but he received a lot of money back slowly. Result, a 1.1 ~ 1.2 TB RAID array. He got a lot more storage and more efficient use of the disks since a RAID 6 with striping allows for drives to be rebuilt in the array.
What he wasn't planning on was the logistics of what he would have to do to his Antec case as a result of all these drives. Fans. Airflow. Heat. These all became huge issues for him--especially in the summer. I'm not sure what your situation is with a case but I made no alterations to my case.
Now, there's a lot of things I skipped over that you can take into consideration, like SATA or ATA? 7,200 RPM or 10,000 RPM? 8MB or 16MB buffer? Striping size? etc. Honestly, those issues aren't worth my time to mess with. Sure sure, I'm losing precious ms seek/read time on my disks but I'm not that motivated.
In the end, if you're only looking for half a TB, do what I did. Those 500 GB drives will only get cheaper and if one blows, just pop another in. And if you really need that room to grow, grab the nice RAID controller that supports RAID 0-6 and just use two 500GBs leaving the other three slots open for the future when you might buy them and RAID 6 it.
What fails? The old IBM Deathstars. Beware!
Linux? What else do you expect slashdot to say? (Score:5, Informative)
On to solutions. Buy yourself a big case (you can do rackmount or regular "large" ATX cases) and stick a decent computer in there. Add Gigabit NIC. Add an 8 port 3ware SATA Raid controller (configured to RAID5). Add 4 120GB 7200RPM SATA Drives (or what ever you can find cheap, even 200GB drives are relativly cheap these days). Install Linux, share your harddrive using Samba. Done.
You have 4 extra ports to expand your RAID if you need too, or you could get bigger harddrives. I think 3Ware cards can support up to 2TB of HD space - so that gives you some expandability. Plus you have a RAID5 which has fault tollerence built in.
Simple answer. (Score:5, Informative)
Everything you need probably. I saw a 1TB version for $700 at Fry's the other day.
It's Time my Son (Score:5, Informative)
Couple questions:
1. SMB only? NFS is faster and plain better, but only for mac/linux.
2. Noise/size/power constraints.
3. Price.
SMB only, moderately cheap, quiet and small, go for a teraserver from buffalo networks. Easy to setup, runs decently, 4x250 drives that can be raid-5'd into a 750 array. Costs about $800.
A good midlevel solution is an nforce4 motherboard, with 4 250 sata drives, total cost around $600 w/ cpu mem, etc. You need a decent case though, and it will be noisier and louder. Plus side is better performance, full customization, and ability to use it as a router or such. You will have to configure it yourself, and likely throw windows on it because the nforce raid support is tricky on linux for a novice.
I use a heavier 2tb solution myself with a HW raid card, but for most purposes a sw raid is better, and the performance difference is almost never noticable. Personally I recommend the buffalo if you don't need nfs, just for the size, quietness, and convenience.
Lightweights.. Try 3.5+ TB (Score:3, Informative)
I have good enclosures and run all my drives cool, 25-29C. Two 120mm case fans, one front, one rear.
I am guessing there isn't anything that can compete with the price-performance of just building another Linux box with 7 or so drives. Is there?
inventgeek.com (Score:4, Informative)
A very basic rule (Score:5, Informative)
As for the solution, the cheap and easy option nowadays is to simply use stock motherboards - most will accomodate 4 SATA drives and up to 4 PATA drives with no extra work - and run Linux with software RAID on them. It's still a problem to boot from a RAID disk, so one can be set aside for that purpose. Motherboards have GigE nowadays, so speed is not limited by the network link. 300 GB drives are cheap, making a 1.5 TB server affordable if you acquire it piecewise over the course of a year or two.
Now duplicate this setup into 2 boxes and you're good to go.
Re:RAID (Score:3, Informative)
Avoid the Netgear SC101 (Score:5, Informative)
Recently I was also shopping around for a storage solution. At the store, I saw a promising looking device called the Netgear SC101. You pop any two IDE drives into it, plug an Ethernet and power cable in the back, and you have yourself a NAS. Because you can pick out your own drives, you can even do a terabyte in a cheaper and much smaller unit than 4 x 250 GB units like the Buffalo Terastation.
Unfortunately, where this device failed for me was that it doesn't just share the stuff as a SMB share like a real NAS box does. It uses some weird proprietary protocol, and only machines with the right drivers installed can talk to it at all. Such drivers aren't available for Linux, or Mac, or BSD... even versions of Windows that are old (98, ME, etc.) or 64-bit won't work. It has to be a 32 bit version of Win 2k3, XP, or 2k with the right service pack level for the drivers or no data for you.
No self-respecting geek would want a device with such limited compatibility. If a piece of network equipment only lists Windows in its compatibility, that normally means the manufacturer only officially supports Windows, or maybe you need Windows to set up and administer the thing. When even many versions of Windows can't access the device, it's a junker. I took it back the next day, and will start researching hardware purchases more carefully in the future.
In short, Netgear's short-sighted decision to use some strange proprietary protocol instead of SMB turns this unit from something I would have strongly recommended into that gets a definite thumbs down.
Re:It's Time my Son (Score:5, Informative)
Infrant ReadyNAS (Score:4, Informative)
I own the X6 and love it.
- It's GBE is very fast.
- It supports raid-5 with up to 4 drives. (mirroring on 2 drives)
- You can just keep adding bigger drives. so it'll be highly expandable down the road.
- Supports SMB, NFS, FTP, etc.
It's $600 for the unit with no drives.
Check out the toms networking review, it's linked from Infrants site.
Re:The Poor Man's RAID Array (Score:3, Informative)
Second Promise can never be considered a "nice" controller. It works, it's fairly cheap, but it's consumer grade stuff.
I wouldn't bother with a cheap RAID controller. Go with md raid in Linux. It's free, you never have to worry about finding the same controller again if the one you have dies, performance is decent (almost always better then cheap RAID cards), and it works really well all around. You might need a PATA or SATA controller to add more drives but those are cheap. High end stuff where performance is critical you get a high end RAID card.
Re:Simple answer. (Score:5, Informative)
Buffalo and Infrant (Score:3, Informative)
We just got a couple Buffalo TeraStation [buffalotech.com] units at work. The software that comes on the CD is a peice of junk, but the unit itself seems good. The major drawback I've heard about it is that it's really slow in RAID5 mode. Not too big a deal for us, as it's a cache sitting in front of tape, so it's still a faster backup medium. It's obviously running Samba in the background, but it doesn't support NFS mounts. I don't know if that's a big deal for you or not.
The other company I've heard about is Infrant [infrant.com]. Similar setup to Buffalo, only instead of being mistaken for a Bose subwoofer, it looks like a small radio circa 1920. It claims an impressive set of awards, but I don't know if it's any faster in the RAID5 department than Buffalo.
But, for home backups that are occurring overnight, and if you're not pushing 100+GB at a time, you're probably good with either. They're both, depending on capacity, between $800-$1,500.
Redundent Network Storage on the cheap (Score:2, Informative)
The NSLU2 runs Linux and can be hacked so that you can setup more complex cron jobs to do your backups, if desired.
Re:RAID != backup (Score:5, Informative)
Most home users are better served with having an extra harddisk that they backup to (may recover accidentally deleted files) than RAID. There are many programs to do that automatically. Of course, burn (high quality) DVDs regularly of the most important data.
My recommendation (Score:3, Informative)
My basic requirements are:
RAID 5 support
Extensive HTTP based admininstration
Samba, NFS, rsync share support (browsing files over HTTP - a plus)
Gigabit Eithernet Interface
20MB+ Read/write speed
Support from 1 to at least 4 SATA disks
Disks should be easily swappable
A few month ago I finally came across Infrant's ReadyNAS X6 box. Specs read like just what doctor ordered - everything I wanted seemed to be there. I got it and after 3 months of use I am not disappointed. I purchased 4 300GB Maxtor MaxLine drives and got about 850GB of NAS disk space. I use it as a primary storage for MythTV, backing up two laptops [rsync], and (obviously) the rest of my data which is now much safer on RAID. The box runs Infrant's custom Linux distro and (I think) Motorolla 350Mhz CPU. It has a dedicated XOR chip. Array upgrades are seamless - you can start with just a single disk, then to RAID 1 (add another disk), then RAID 5 (3 and 4 disks).
The only thing that I was hoping would be better was write speed - I get about 15MB sequential write and 25MB seq. read speed. After some digging, I get a feeling this is actually a problem with network card not being able to keep up with packets. If that's the case, I might be able to pop another network card in one avaliable PCI slot.
As far as price goes, Infrant's box and 4 300GB drives cost me under $1K USD which seems quite reasonable. I highly recommend taking a look at this unit if you are considering purchasing NAS.
BTW, I am in no way affiliated with Infrant, just a satisfied customer
Dead Simple/Cheap ($80 + 2 ext enclosures & HD (Score:5, Informative)
Also, with this scheme, you can delete a file and change your mind. (Recover from the back-up before the weekly copy job.)
And, if this is too simple for your geek quotient, it's Linux-based [batbox.org] and hackable [tomsnetworking.com]!
Re:The Poor Man's RAID Array (Score:3, Informative)
Re:The Poor Man's RAID Array (Score:1, Informative)
So, now having gotten the case (with 12v large diameter fans) the 600 watt PSU, the removable drive bays, and the multiply tested drives (I'll get into that more in a bit), the problem becomes the RAID interface cards.
I went with software RAID on linux, and having learned from a previous drive failure why it was important to keep drives on separate channels (do NOT put drive on master/slave - an ide failure on one just might take out the other, and simultaneous failures do bad things to RAID5 arrays), put in (3) Maxtor ATA/133 cards.
Bad mojo happened, and as it turns out, having more than (2) of those cards in the 500MHZ dual processor celeron system I was using causes some sort of instability. I eventually subbed in a ATA/133 card from another vendor for the 3rd card, and used an ATA/66 interface from the motherboard for the 7th drive.
Everything's good right? Well, no. After setting up the array, formatting it, and rsyncing the contents of the
Of course, during this entire ordeal, I had a UPS hooked up to the server to ensure that it did not suffer any damage from blackouts/brownouts.
Total time to set the RAID up? Several months. Total time to test and copy data? Three weeks, and counting.
Obviously, now, if I was setting up a RAID for work, I'd buy one off the shelf with on-site service guarantee (this RAID was for home)...
Re:The Poor Man's RAID Array (Score:4, Informative)
And if someone is looking for some RAID card reviews... Here's a couple links:
http://www6.tomshardware.com/2006/01/02/safer_6_f
http://www6.tomshardware.com/2005/10/31/sata_spel
(Yeah Yeah, THG... Still a good roundup and worth the read if you're looking for a card - jump to the feature table on the last page if you don't want to read the whole thing)
Lots of people seem to mention the 3ware cards, but at that price I'd rather get the nice Areca ARC1220 instead (which is also PCIe - no PCI-X req'd)
I'm looking for a similar solution, but even though these cards look very nice, I'll definitely go with software RAID5 too, those controllers are too expensive... I'd rather spend the extra money these controllers cost on more storage (that 500$ will buy around 1TB).
Re:It's Time my Son (Score:3, Informative)
Just picked up a Linksys NSLU2UK nas, which works like a charm as well for 'near-line' storage. A bit slower, but takes 2 USB drives. I'm thinking she will do more, but have not cracked the case and pulled out the soldering iron yet. (grin)
Re:Linksys NSLU2 (Score:4, Informative)
I can't believe anyone would recommend anything else for a geek besides the NSLU2!!
It runs based on Linux, so you can replace the firmware [nslu2-linux.org]
Not only do you have a NAS device, which you can mirror disks on, but then you can basically add on whatever you want, eg Firewall, web/mail/file server, music center, VOIP PBX, use NFS as well as Samba etc.
Tom's Networking has a little howto [tomsnetworking.com] on this.
And if you're interested in more information, CmdrTaco I've found this other site [google.com.au] where you can often find some good information from users about techy related stuff that matters.
Re:2.5 Terabytes of storage (Score:2, Informative)
Avoid the NSLU2 (Score:4, Informative)
- Silent operation, no fans in the nslu2 and you can get fanless enclosures for the HDs
Make sure it's an aluminum case at least. And be prepared to try several different ones until you find one that works well.
- Takes very little space away from your home office
No, other than the six thousand cords you've got hanging off the back of it to plug in these external drives.
Oh, and don't accidentally disconnect a cord. The NSLU2 doesn't support anything approaching to Plug and Play. You'll likely damage data on the drive, but the most annoying thing is you gotta shutdown and restart the whole thing.
- Very small power draw
True.
- Easy to add/remove drives without any reboots
Not in my experience.
- Can power off drives that aren't used frequently, then turn them on when needed
Again, not in my experience. This is most likely going to lock up the whole thing so it stops responding.
The other problems with the NSLU2 besides the speed(might as well hook it up to a 10baseT hub, cause it can't fully utilize 100baseT), is that if you do try to transfer a large amount of data(say 15 gigs of MP3s) more likely than not the whole thing will lock up on you.
In short... The NSLU2 is unreliable, for a variety of reasons mostly having to do with software, but also having to do with the external drives and the lack of support for hot plugging USB devices. The NSLU2 is slow. The NSLU2 is a pain to manage on the table because of all the cords hanging out of the thing. The NSLU2 is not well supported by Linksys, they periodically release firmware updates but 9 times out of 10 they don't help. The NSLU2 is particular about what type of USB enclosure you use, as well as even what drive, so it's hit or miss whether it will work.
To be fair, I did look at buying a Netgear SC101, and everything I have read indicates that it's even worse.
I ended up just taking my drives and sticking them on my computer and leaving them there. I thought it would have been nice to have this running all by it's lonesome in another room with some batch scripts periodically replicating data over to it. But it's simply not reliable enough.
I've been meaning to try to sell my NSLU2 on ebay. Maybe someone who wants to install their own copy of the nslu2 Linux on it can have some fun. But it's not a good device for a SOHO server, that's for certain.
Re:Simple answer. (Score:4, Informative)
For backups I run some nice Plan 9 [bell-labs.com] magic - the Venti [bell-labs.com] archiving file server. No-hastle incremental backups, snapshots of previous days, identical-block compression, and so on. It's been ported to Unix (and so runs on my Mac), and provides more peace of mind (coupled with the raid) about my data than I thought possible.
Re:Linux? What else do you expect slashdot to say? (Score:3, Informative)
Re:Infrant ReadyNAS (Score:2, Informative)
Simple solution (Score:2, Informative)
Infrant ReadyNAS X6 is the best NAS period. (Score:5, Informative)
Of course it does CIFS(SMB). But it is one of the only NAS products to support Apple File Protocol, which is a must for networks with Mac/OS X users that insist on using filenames with colons, slashes and question marks and other things that make CIFS/SMB explode. It also supports NFS and rsync for the UNIX/Linux crowd and both FTP and HTTP for the web browser crowd (hi, grandma). It also streams in both flavors of home media server protocols (UPnP and the HMS) so you can buy a $100 Linksys media extender and watch anything you have stored on your RAID. It also has a SlimServer plugin for streaming music to those SlimServer devices that you can hook up to your stereo or a cheap pair of speakers.
It's also supports Gigabit with Jumbo Packets (write only currently) so you can copy 200GB of HD camera footage to the NAS in a couple hours instead of a couple days. The RevB case is cable-less with just thumbscrews between you and swapping a drive. It also holds the drives vertically because who is the idiot who thinks stacking heat factories horizontally on top of each other is a good idea. Also, I can't tell you how many RAID products only lets you specify an alert SMTP server name but no authentication information, which means e-mail alerts don't get delivered (boo Promise, boo 3Ware). ReadyNAS has its own MTA so the mail gets through without a problem, and it can also let you set login/password to authenticate to your ISP's SMTP server. It looks nice, clean, and it certainly not the noisiest thing I've had in my room, although I will be happy when future firmware lets you put the drives to sleep so the case fan can be completely turned off when you aren't using it.
I spend three weeks shopping for a NAS for my network, and I'm glad I looked past everyone telling me Terastation. I've had this ReadyNAS X6 for a few weeks now and I love it. I'm already shopping for a second so I can recycle the old drives from all my other rag-tag household systems into one nice neat package.
-JoeShmoe
Re:Avoid the NSLU2 (Score:5, Informative)
The linksys firmware might suck, I don't know, having scraped off the linksys dreck immediately upon plugging the device in.
You might just give unslung a shot. It's easy, and fixes most (all?) the complaints you've mentioned.
Re:Infrant ReadyNAS X6 is the best NAS period. (Score:5, Informative)
For USB printer connected to the back, the ReadyNAS works as a print server. If you add USB storage (almost everyone already has a USB drive kicking around somewhere) then that storage is available as a volume on the ReadyNAS. You obviously can't use it for part of the RAID but it is fantastic for loading up a drive of movies to take over to someone's house or bringing data from other homes/offices to backup on the RAID.
The ReadyNAS can also be configured to automatically copy data from any flash storage to a specified directory. So you have a camera with a CF or SD card, right? Get a USB card reader, and every time you plug your camera's flash card into it, it will copy the pictures over to your
Since the underpinnings are all Linux, it's a sure bet that the PCI and USB ports will provide all sorts of cool amazing things as time progresses. I fully expect that you'll someday be able to add a second NIC and have the ReadyNAS function as a firewire...sorta like that big ugly yellow banana slug NAS that was reviewed on here a few months ago.
-JoeShmoe
Snap Server (Score:2, Informative)
Re:Linux? What else do you expect slashdot to say? (Score:3, Informative)
My 3ware couldn't care about model. It's the *size* that matters. The replacement drive has to be >= the size of the drive it's replacing.
roll your own with openbsd and netatalk/smb (Score:3, Informative)
BIG TIP!!! get a frackin' UPS! i'm currently using an ancient APC smart 2200, but i've had fewer flakey problemsthe last three years i've been running with a UPS, and i think alot of it is just having clean power... of course my sysadmin chops might have gotten better as well, but i'm pretty sure clean power goes a loooonnnng way.
finally, as far as file sharing is concerned, i prefer netatalk cause i'm a long time mac user(as is my wife) and i've been a sysadmin in the graphic arts for a long time. netatal 2.0.x works very nicely on openbsd. but you should run whatever file sharing (netatalk, smb, nfs) is most conducive to your client OS.
i can't tell you which backup/archive is gonna be the best for you... if i could run legato networker on bsd cheaply, i would. i'm leaning towards bru for the time being, but i'd like to explore amanda some more.
good luck.
Re:RAAAIIIID???? ::boom:: (Score:4, Informative)
I don't know RAID 6 and 50 well enough to explain them, so the link will do the job. While I'm at it, they can do 10 (compare it to 0+1 to understand better)
RAID 6 [raid.com]
RAID 10 [raid.com]
RAID 50 [raid.com]
Re:Avoid the NSLU2 (Score:4, Informative)
I have 4, two are adaptec and 2 are two different compusa house brand cheapo things. Never had any problem, didn't know that it mattered or I might have skipped the cheap ones.
> No, other than the six thousand cords you've got hanging off the back of it to plug in these external drives.
Well.. its not 6,000... but it does take enough to be a little bit of a hassle. I have 4 hds connected, so of course there are 5 usb cables (one per HD and one from slug to hub). And then you have power cords for the slug, hub, and HDs.. thats 6 all together. 11 cords, and then you have the ethernet out fron the slug for 12 total I think. 6000>12, but still I guess if you dont like cords, 12 could really freak you out.
> Oh, and don't accidentally disconnect a cord. The NSLU2 doesn't support anything approaching to Plug and Play. You'll likely damage data on the drive, but the most annoying thing is you gotta shutdown and restart the whole thing.
Not on my slug. ReiserFS avoids any nasty problems with damaging data, and I have only restarted my slug once (new kernel) since I installed Debian over 6 months ago. Of course I haven't tried disconnecting the root drive, that would probably not work out well. But all the other drives are regularly turned off or disconnected. no problems at all. You need to use disk labels since the device numbers can move around a bit, otherwise its been perfect.
> The other problems with the NSLU2 besides the speed(might as well hook it up to a 10baseT hub, cause it can't fully utilize 100baseT), is that if you do try to transfer a large amount of data(say 15 gigs of MP3s) more likely than not the whole thing will lock up on you.
Man you must have gotten the crapmaster slug from hell. I literally filled the first 300GB drive I connected in a single ftp session, not one error or problem. I regularly dump large amounts of data to/from the device and never have seen any problems. Sure, its not exactly fast, but plenty fast for 2 users to watch divx off of at the same time. The only time I saw a performance problem was when I tried to do a native compile of a new kernel on the box itself.. took several hours due to excessive swapping and during this time video was choppy every once in a while. Still better than I thought it would be.
> it's not a good device for a SOHO server, that's for certain.
All I can say is "sorry about your luck". This thing rocks as a SOHO server!!
He already has that (Score:5, Informative)
He does care about downtime. Downtime = time spent restoring. With a RAID level > 0, all he has to do is replace a drive and tell the raid to rebuild. He's done in 5 minutes. It would take that long just to queue up a restore job for the tape.
Hardware VS Software Raid (Score:3, Informative)
The $13 card you purchased is software Raid. Promise cards are mostly hardware RAID. I recently purchased a Promise FastTrack S150 SX4-M for less than $100 hardware RAID5 card compared to the $30-50 software RAID5 cards. I'm pretty satisified with the purchase but unfortunately there isn't room for much upgrade. I currently have 4x160GB in a RAID5 configuration giving me 480GB of space and 1 disc of redundnacy.
Some useful links to tell you the difference between software raid and hardware raid are:
http://www.pcguide.com/ref/hdd/perf/raid/conf/ctr
http://www.redhat.com/docs/manuals/linux/RHL-9-Ma
http://techrepublic.com.com/5100-10880_11-5715216
http://www.linuxplanet.com/linuxplanet/tutorials/
Re:Linux? What else do you expect slashdot to say? (Score:2, Informative)
Rather than a dedicated cheap nas device, i decided to go with a DIY linux software raid array. The current linux software raid is pretty reliable. if your doing mission critical data, i recommend hardware raid instead however. To estimate this, try to attempt to guage the cost associated with re-gathering all your data, and spend at least 1/4 that much for your storage.
My solution was 4 200gb ata seagate baracuda drives in sw raid 5. the cost was about:
- 4 drives @ $125 cdn
- case & powersupply @ $100 cdn
- board, cpu, 512mb ram @ $200 cdn
total cost - 900$ cdn
i used the onboard ide controller for a 80gb os disk, and a separate 2channel pci ide controller for the 4 disks, in raid 5, giving about
achilles:/storage 559G 474G 86G 85%
i've been using this volume for about 1.5 years now with no problems *knock wood*. I've also rebuilt a sw raid 5 array at work, so i know that part of it works (for the most part).
A few benefits i find using linux rather than a hardware device:
- i can ssh/winscp in and get any of my files, anytime, from anywhere
- i can run apache, mounting my
- nfs or smb mount the volumes to any other linux/windows machines
- the geek satisfaction of having my own
my next step from this is to purchase 4-8 SATA drives, a 8channel sata controller, and go with that. One thing to consider, is the location of your system. With this many drives, it can generate substantial heat (and noise), so you probably dont' want it sitting in a warm location in your home, where you have to listen to it droning away (4 cudas make some noise
hope this helps! a good linux sw raid howto is at:
http://www.tldp.org/HOWTO/Software-RAID-HOWTO.htm
One other thing. you can also use the mdadm tools to monitor the volume for any issues, and if/when they arrise, you can have it email you a message. This way you can pick up a spare 200gb drive on your way home from work to replace the failed one
dwight s.
RAID 6 (Score:3, Informative)
--
This executive summary was bought to you by cheese
Re:The Poor Man's RAID Array (Score:3, Informative)
Redundancy and mirroring is the way to go these days. It doesn't much matter if your drive fails if it's just one drive in a RAID that is mirrored in other places on other completely independant RAIDs. In any case, ATA/SATA drives don't fail all that much more than SCSI, at least in the first 3 years*.
Even at work where we store multiple terabytes of business critical data, we use SATA. We just keep 3 independant copies of the data, one offsite. We use incremental rsync snapshots for incremental functionality.
*The great part is that there's no huge investment. If hard disk technology jumps next year, we can upgrade with no guilt, since we didn't sink a ton of money into it in the first place. Previously we'd milk our SCSI RAIDs and tape drives/robots until they were ridiculously obselete and undersized because the cost was so high to upgrade them. It's no big deal to completely replace every drive every 3 years. The upshot is you generally replace all your disks with half as many disks 3 years later, since sizes have doubled, and the cost is about constant. Your RAIDs slowly get more reliable as the number of drives drops every cycle.
You can brag about your baker's dozen of 36 GB 6 year old SCSI drives never failing, but I'll have a few 300 GB drives and have spent less money in absolute terms, and far less money once you count the time value of sunk costs into the equation.
Re:He already has that (Score:2, Informative)
Re:Been working on that (Score:4, Informative)
You don't need to. All the current drives have molex power connectors too, right? If you are unsure, check the specs. Hitatchi's OEM data sheets are great in that regard, since they tell you everything.
Then get a bunch of molex Y-adaptors, they're really cheap. I haven't seen SATA power Ys yet, but hopefully that's just a matter of time.
Take a good look at the current requirements for the drives though. At 12 drives you're heading into the region where most PSUs won't supply enough current. The startup current for 12 current hitachi sata drives is 1.8*12=21.6A at 12V, and most PSUs are only rated at 12-18A.
Also, watch 5V too, the current draw at "max r/w"-load is 1.3A on both 5V and 12V (on those hitachi drives). Even beefy PSUs in the 600+W range most of the time only have 20-30A at 5V, even when they have 3x18A 12V. That's probably enough for 12 drives, but if you want to scale it up you can run into stability problems.
I know this, since I just put together a machine with 18 drives in it, and had lots of power trouble at first.
slackware + raidtools + lvm + webmin (Score:2, Informative)
Here's the basic solution:
1. Slackware linux
2. Multiple pairs of harddrives set as mirrors (raid1)
3. Combine these mirrors into a single volume with lvm
4. Share the volume using samba &
5. For easy managment, use webmin
I'm using standard IDE drives because their cheap, and we've got a half dozen laying about. One nice thing about raid1 on linux is that you do NOT need the two harddrives to match in size. The size of the mirror will be the size of the smaller of the two drives. LVM allows me to take a lot of the smallish mirrors (60gb-160gb) and combine them into one large volume (total is 580gb). Because of the mirror'ing, there isn't much concern about a single dead drive taking out LVM.
I'm running this setup with a Pentium III-733mhz w/128mb memory, and have found the only bottle neck to be the speed of the drives themselves. A suggestion about that: Make sure that the two drives of each mirror reside on different ide channels; this improves things noticeably.
peace,
nathan o'brien
Re:The Poor Man's RAID Array (Score:4, Informative)
Hear, hear! I've said it before, and I'll say it again:
RAID is not backup!
If you consider all of the possible things that can make your data suffer, in order of likelihood:
you can see that RAID will only help with item #4. Anyone with any data more important than ripped CDs needs actual hard backup: tapes, DVDs, offsite, whatever.
Re:Been working on that (Score:2, Informative)
Oh, I think you're gonna need a lot more than 300 watts. Double that at least.
I just built a system with 8 400GB drives and a Pentium 3. Started with a 400 watt supply and it wouldn't even turn on. Went an bought an Antec 550 and it turns on just fine, but acts a little flaky now and again. I definately need something in the 600-700 category.
There was a project I saw on the Internet just a bit ago, unforunately I can't remember where, but he had 12 SATA drives and ended up having to buy a 1KW supply. He had a 650 but it wouldn't even turn on. Although, if I remember right he was running dual Xeons, so that could skew the results a bit...
Regardless, you need something much bigger. You could get an additional supply just to power drives. Basically you just need to ground the green wire on an ATX supply to get it to turn on with a connection to a motherboard. http://www.gideontech.com/content/articles/196/1 [gideontech.com] This site will show you how.