[ms] · Est. May 2002
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Gonna build one of these at some point and run RAID5.
Any of you guys using NAS already? Feedback, tips, etc?
Can you run RAID5 with 3 disks or must it be 4? Wiki tells me a minimum of 3, but their diagram shows 4.
I will want an NAS with a built-in BT client so I can take all the load off my Macbook Pro.
Better to buy a NAS with BT, or build a mini-computer?
Re: Network-Attached Storage (NAS)
In order to have RAID5 you need 3 disks or more. I can't comment much on the NAS because I don't use them. I can tell you how to carve a chunk off on a SAN though :)
Re: Network-Attached Storage (NAS)
Cool thanks, will probably start with 3 disks then.
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The more the better. I always use 5 disks, but I work for a hospital and those disks are important (extremely).
Re: Network-Attached Storage (NAS)
beanz runs AIDS, its close, might help
Re: Network-Attached Storage (NAS)
[quote=Funky Dredd;677859]The more the better. I always use 5 disks, but I work for a hospital and those disks are important (extremely).[/quote]
5 disks? :shock::what Does more = less corruption should failure occur?
Re: Network-Attached Storage (NAS)
No but you can lose 2 disks and still be good. Remember I work at a hospital and data is extremely important.
Re: Network-Attached Storage (NAS)
In a classic raid5 setup you can only lose one disk maximum before data loss will occur. therefore you could technically have 11x1TB disks and get 10TB of usable diskspace, the last 1TB drive being used as parity. the parity for the entire volume is striped across all disks in the volume and therefore can with a loss of one disk the data can be recovered. But the higher number of drives the greater the chance of a disk failure, therefore the faster you need to repair it before dataloss, or also a higher MBTF which could have two disks fail at the same time which would mean goodbye data. it sounds like dredd above is doing something with double parity, probably raid6 or a hotspare, since he says that hospital data is so important this is common and can survive more disk failures before the data gets corrupted, but for normal raid5 it is one disk failure max before you are SOL.
most diagrams seem always reference 4 drives for raid5 but the max you would need is 3 to start. another issue is you need to be aware that you might not be able to online relayout your raid setup if you decide to add another drive in the future. therefore you have 800G of data on your setup and its almost full and you cant expand it w/o destroying it and recreating it. so you will need someplace to temporarily put that 800G while you recreate your volume. i think this can vary based on underlying raid card / volume manager program though so dont quote me.
this also is good explaining the different basic raid levels, with pics: [URL]http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5[/URL]
Re: Network-Attached Storage (NAS)
[quote=res0nat0r;678133]another issue is you need to be aware that you might not be able to online relayout your raid setup if you decide to add another drive in the future. therefore you have 800G of data on your setup and its almost full and you cant expand it w/o destroying it and recreating it. so you will need someplace to temporarily put that 800G while you recreate your volume.[URL="http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5"][/URL][/quote]
WTF ... is this the same with all RAID? :what
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heres a demo video that might help you with NAS:
[YOUTUBE]nMn2cCBwH18[/YOUTUBE]
Re: Network-Attached Storage (NAS)
one of my favorite rap songs of all time.
Re: Network-Attached Storage (NAS)
[quote=res0nat0r;678133] it sounds like dredd above is doing something with double parity, probably raid6 or a hotspare, since he says that hospital data is so important this is common and can survive more disk failures before the data gets corrupted, but for normal raid5 it is one disk failure max before you are SOL. [/quote] Yes I have it setup as a hot spare.
[quote=feather;678154]WTF ... is this the same with all RAID? :what[/quote] Yes. There is no way to add a disc to your RAID later for more space. Although I shouldn't say that, because you can add more space if you are using a SAN. If you have a SAN and you are running out of space on your LUN you can expand that LUN by creating a MetaLUN and then run diskpart (on Windows) and then expand it. Providing the expansion LUN is setup in the same RAID that the original LUN's RAID is. You cannot expand a LUN that is RAID 1/0 with a LUN that is RAID 5. They have to be the same (RAID 1/0 to RAID 1/0). Of course a SAN is most likely out of your budget (I know it is for mine)! But like I said I don't know to much about NAS devices, so this could be possible to do. I would have to do some reading in order to determine that.
Re: Network-Attached Storage (NAS)
check out freenas.org
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Hmmm that looks interesting, it seems to come with bittorrent. But software RAID? Is that slower than hardware RAID? Any cons?
Re: Network-Attached Storage (NAS)
If you're handy with a soldering iron but a [URL="http://www.thecus.com/"]Thecus[/URL] N1200 & check out [url]http://www.openbsd.org/socppc.html[/url]
If the NAS is only going to be used by yourself you'd be better off going for RAID1, RAID 5 is overkill, adds the cost of an additional disk & will put a load on the CPU if you're using software RAID or a pseudo controller.
Re: Network-Attached Storage (NAS)
[quote=feather;679584]Hmmm that looks interesting, it seems to come with bittorrent. But software RAID? Is that slower than hardware RAID? Any cons?[/quote]
Yes it is slower but depends on how many users you're going to hang off the NAS, if its just for yourself & your pr0n stash you're not really gonna see that much difference if the hardware that you're using is from the last few years. If you have your heart set on going down the hardware RAID route don't forget to get a controller with a battery backup otherwise its a wasted effort but that will add a serious amount to the cost.
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Can't remember why I picked RAID5 when I was reading up on this stuff, isn't RAID5 faster??
The Thecus looks like it might serve my needs but it only holds one disk so I can't run any RAID on it ... ?
Re: Network-Attached Storage (NAS)
RAID 5 / 6 start showing their advantages in speed when the number of disks go past 6, you'd be better off using RAID 1 (2 disk mirror) or if you're hardware controller supports it RAID 10 (4 disks, mirror,stripe), don't forget its only writes which suffer on RAID 1 as the data is duplicated, where as reads are sped up as you read across the 2 disks.
Re: Network-Attached Storage (NAS)
as for the Thecus you have a esata port for your aditional disk. saying that be prepared for a steep learning curve to hack the box & get everything setup as you like.
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Hmm cool thanks for the info regarding RAID1. I was browsing around on forums and came across the D-Link DNS 323 which seems to have everything I want, for AUD268 ... that sounds like the simpler route :what:lol:
Re: Network-Attached Storage (NAS)
get hacking [url]http://wiki.dns323.info/[/url]
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Yeah the forum where I came upon the 323 linked to the site, and a forum with people using it. Seems like there are some stuf you can install on your own, including the Transmission Bittorrent client which I presume would be better than the bogstandard default, and I happen to use Transmission on my Mac as well so that would be good.
Re: Network-Attached Storage (NAS)
looks like all the essentials are there via the fun_plug script without having to resort to using a jtag & reflashing. [url]http://forum.dsmg600.info/index.php[/url]
Re: Network-Attached Storage (NAS)
Yeah I'm assuming this fun_plug thing is a simple package thing like most *nix distros to update or install stuff ...
Good reviews and a good community around it, most likely give it a shot once I get some money together :what:lol:
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now im content with maybe buying a drobo.
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raid5 isnt overkill, its all based on how much space vs cost you want to spend your money on.
two 500g HD's in raid 1 = 500g in space. or (3 or 4) 500 G HD's in raid 5 = 1TB or 1.5TB of space
its all about how safe you want your data and how much money you want to spend on it. if you arent going to be running a warez site with 50 people uploading and downloading movies I dont think software vs hardware raid is going to be noticeable.
i am trying to find a small form factor box that i can put 4x500g drives in that i can install a minimal linux distro on which will also run mplayer so i can play x264 movies from it to my 50" hdtv.
Re: Network-Attached Storage (NAS)
[quote=res0nat0r;679805]two 500g HD's in raid 1 = 500g in space. or (3 or 4) 500 G HD's in raid 5 = 1TB or 1.5TB of space[/quote]
My 4x500GB RAID5 Array in my workstation:
Re: Network-Attached Storage (NAS)
as for software vs hardware raid, software raid & pseudo raid controllers will always impact system performance because all the work is passed onto the cpu & onboard controller whereas with hardware raid there is a processor on the card + a large ammount of cache which if you don't have battery backup gets switched off along with the onboard cache on the disk, then see how long read & writes take from your disk!
as for data safety, like you said earlier you can only tollerate the failure of one disk, you only start to reap the benefits of RAID 5 & 6 once you get into arrays with more then 6 disks, for something as simple as a DVR/mediacentre where you're doing more reading then writing its a waste of money & resources unless you're planning to record multiple video streams simultaneously in which case you're idea of using a small form factor box will not stand up to the job. PSU & Cooling in such a small case being one of the initial hurdles to get you going.
Re: Network-Attached Storage (NAS)
[quote=venture37;679931]My 4x500GB RAID5 Array in my workstation:[/quote]
this wasnt accounting for all of the overheard involving the actual physical space you get from the drive plus the space loss from filesystem overhead etc...which unfortunately you cant get around. but you are right the actual space is going to be much less than 2*X number of drives.
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[quote=|Thrax|;679670]now im content with maybe buying a drobo.[/quote]
yea i am thinking about that myself...
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i think i saw some reviews on that thing and they said that the data xfer rate is pretty damn slow. i need to see if i can find that...
Re: Network-Attached Storage (NAS)
[url]http://www.maximumpc.com/article/data_robotics_drobo[/url]
[QUOTE]Saying the Drobo is slow is like saying dry ice is cold or that the Buckeyes are just another football team. Running our HD Tach benchmark test on the Drobo was like waiting for water to boil, only to find that the burner wasn’t even on to begin with.[/QUOTE]
[url]http://www.asitis.org/drobo-review[/url]
[QUOTE][B]The Drobo is Slow[/B]. Don’t expect amazing throughput with this machine. With the virtualization layers and multiple writes to the different drives, it takes some time. The real annoyance here is that a two-hour movie will usually hang a couple times if writes are happening in the background.[/QUOTE]
[url]http://mac360.com/index.php/mac360/comments/drobo_the_best_mac_home_backup_system_ever/[/url]
[QUOTE]Slow? Yes, though it isn’t too noticeable if you’re using Time Machine. After all, Drobo is a back up system; it’s for system storage, perfect for home use, small office use, not corporate file [URL="http://mac360.com/index.php/mac360/comments/drobo_the_best_mac_home_backup_system_ever/#"][COLOR=#000080][COLOR=#000080 ! important][FONT=Verdana][COLOR=#000080 ! important][FONT=Verdana]servers[/FONT][/COLOR][/FONT][/COLOR][/COLOR][/URL]. The specs say maximum sustained transfer rates are a mere 20MBs per second; not speedy. Hard drives need to be SATA I or II, the kind that come with Macs these days. Four drives use barely 40 watts of power under use. [/QUOTE]
Re: Network-Attached Storage (NAS)
[quote=venture37;680496][URL]http://www.maximumpc.com/article/data_robotics_drobo[/URL]
[URL]http://www.asitis.org/drobo-review[/URL]
[URL]http://mac360.com/index.php/mac360/comments/drobo_the_best_mac_home_backup_system_ever/[/URL][/quote]
ALL of those reviews are referring to the 1st generation USB 2.0 version of Drobo.
They recently released 2nd generation which has Firewire 800, which screams.
One caveat from reviews of Drobo2 that i have read is that Windows Vista Firewire 800 drivers suck really hardcore so getting this for a Windows machine does have mixed results. Works awesome for Mac's though.
Re: Network-Attached Storage (NAS)
I stand corrected