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+--- Thread: FreeNAS versus unRAID as the operating-system for a DIY NAS? (/showthread.php?tid=82811)
- GJones - 2010-10-14 20:08
gadgetman Wrote:UnRAID is great, I love it. But I hate their tech support, it's virtually non existant. You need to depend on the community forum to troubleshoot things.
Which is horrible, since you are commenting on the lack of quality of community support on the community support forum for another piece of software.
I've seen few people have a problem with unRAID: buy hardware that is certified and it works. I've asked quite a few questions along the way and never had to wait more than an hour or two to get not just an answer but the correct one.
- GJones - 2010-10-14 20:12
darkscout Wrote:Unless they want to watch the same thing.
I'd love to see the specifics on this issue. Striping would have the same issue to nearly the same extent in most configurations.
How many times do you have the situation where two different clients are streaming the same HD show to two different clients. In my home we tend to watch the same show/movie together instead of apart.
- poofyhairguy - 2010-10-14 23:11
darkscout Wrote:Unless they want to watch the same thing.
Unraid is more than capable of streaming THE SAME HD movie to up to three clients. I have tried. In fact I tried with the "free version" before paying for the pro and that is what convinced me to put down the money.
It makes sense as a lone HD by itself can do that, and Unraid basically gives performance slightly below what HDs by themselves offer (due to the slight overhead for the user shares).
More than three clients (Or maybe EXTREMELY high bitrate HD content like 40GB pure Blu Ray rips) will have trouble, and for those cases maybe a ZFS server (and a pretty awesome gigabit network) would be needed. But honestly how often will a family watch the exact same show in more than one room at once, and how many consumers have network hardware that can take those loads?
- TugboatBill - 2010-10-15 01:34
Why would you want to watch the same thing 3X off the same NAS/server simultaneously?
- darkscout - 2010-10-15 02:21
TugboatBill Wrote:Why would you want to watch the same thing 3X off the same NAS/server simultaneously?
It was a case to illustrate a point.
What if you have 3 people watching different things that happen to be on the same hard drives? Something at the beginning of the 1st platter. Something at the middle and something at the end of the 3rd platter?
Technically it should work given that SATA is 3Gb/s. But given you have 3 different clients trying to access 3 different points on he same hard drive at the same time...
- poofyhairguy - 2010-10-15 03:05
darkscout Wrote:It was a case to illustrate a point.
What if you have 3 people watching different things that happen to be on the same hard drives? Something at the beginning of the 1st platter. Something at the middle and something at the end of the 3rd platter?
Technically it should work given that SATA is 3Gb/s. But given you have 3 different clients trying to access 3 different points on he same hard drive at the same time...
I did that too. In fact, I did that first before I tried playing the same thing. At the time the Unraid test box only had two data HDs and on one I put HD movies and on the other I put HD TV to test.
Unraid was able to deliver three 10-14GB mkv movies from the same drive at the same time. As I said maybe with really high bitrate stuff you couldn't get away with it, but I know at least 2 Blu Ray level streams from the same drive work in Unraid because I tried that more recently on my Pro Box.
In my experience when it comes to reading data, Unraid can outdo my cheap gigabit network. I would have to put some real money into my network to support enough clients to be able to outdo my Unraid box.
On writes though its a different story, and a good reason for a ZFS box.
- BLKMGK - 2010-10-15 07:47
froggit Wrote:I can't say for all RAID systems, but with ZFS you can choose your preferred level of redundancy. For example, if you're happy with the capacity of one disk for parity data then you could choose a simple 2-drive mirror, or RAID-Z1. If you want more safety then you can choose double-parity like RAID-Z2. If you want triple-parity then you can choose RAID-Z3, which allows three drives to fail before you lose any data.
So depending on your wallet / paranoia level, you can choose a level of data safety that suits your own situation.
So if I choose a single parity drive and two drives fail what's left? What data recovery tools do I have available for the drives that failed and I pulled? How many drives worth of data did I have to sacrifice in your example? Must all of those drives be spinning for me to watch a movie?
froggit Wrote:Why not use enterprise-level data safety mechanisms that are *free* and available within ZFS? What happens with unRAID if your parity drive dies, or one or two of your data drives dies? With ZFS, using RAID-Z2, if *any* one or two drives die you lose no data, and you can rebuild any dead drives so *no* data is lost.
If my parity drive fails I lose no data. If I lose TWO drives I lose two drives worth of data but can use standard repair tools or services to recover them. If I lose a parity drive and a data drive I lose one data drive worth of data. You don't understand how unRAID works do you? It shows.
froggit Wrote:USB sticks are not generally suitable for booting OS's from as they tend to write frequently to the devices (logs etc), and this will reduce the life of the USB stick. They are also fairly slow to boot from.
My USB stick isn't written to during a normal course of operation and I reboot my server maybe once every couple of weeks to months - it boots in about 2minutes. I lose ZERO storage space to my OS which boots from a USB stick. I take it you're telling me that's not the case for you?
froggit Wrote:Solaris has corporate support from Oracle.
Solaris X86 is corporately supported still?
froggit Wrote:Also, for ZFS newbies there is a great forum available on the OpenSolaris.org site which is frequented by very knowledgeable & helpful ZFS users - see here, including Oracle staffers: http://opensolaris.org/jive/forum.jspa?forumID=80
Umm, unRAID is supported by folks too including the guy who wrote the software. Mind you the forum is dedicated mostly to folks using the software to run a NAS and not a general OS.
froggit Wrote:ZFS is simple - here I will create a 6-drive array which can survive any two drives failing before any data is lost:
# zpool create tank RAID-Z2 drive1 drive2 drive3 drive4 drive5 drive6
How much data space are you losing for that level of redundancy? Must all drives be spinning if I watch a movie? ZFS spans drives right?
froggit Wrote:<snip>
Voila, what's hard about that?
Now, for one of the killer features of ZFS, that virtually no other RAID system has -- the ability to find and repair all files that have become corrupt due to 'bit rot':
# zpool scrub tank
This last command will read the contents of *all* files within your storage system and compare each block with a 256-bit block checksum. Any blocks not matching the checksum will be recovered by using the parity data stored when the file was originally created. This feature is priceless and gives you peace of mind that your data is 100% correct as it should be. Can unRAID or FreeNAS do that?
I guess my question is do I need it to do that? Yeah, I CAN run a parity check and I CAN get data errors corrected. Mine runs monthly as I recall. How much space are you dedicating to storing that checksum?
Look, my needs are pretty simple. I store mostly video and I want to use as much disk space as possible while using as little electricity as possible. I want the array to be fast enough to stream my data and I want it to be able to suffer the inevitable drive failure. For the fool who calls those of us using this system "fanboys" for defending it it's pretty apparent you don't understand the fact that this system meets all of or needs and has in my case for something like 5 YEARS now.
- BLKMGK - 2010-10-15 07:54
froggit Wrote:Not if the data is in cache. ZFS uses available free memory to store files read.
However, it will need to spin the drives if data is not in cache.
Ah, so all drives need to spin, an answer at last. My movies are far larger than the 2gigs of memory in my systems.
froggit Wrote:However, for energy reduction, you may use the OS power management features to spin-down drives after a set time period like 5 minutes, and a lot of the 'green' drives auto-park heads for reduced power usage anyway.
And then they all spin back up when I read a file because the system spans them across multiple disks right? You realize that's not the case with unRAID right?
froggit Wrote:You are very generous. I am not willing to lose any data. And the price of 2 drives to give peace of mind helps me sleep really well. And I have a backup of everything.
No it is you who are very generous using multiple disks to provide parity. Why stop at two drives? Why not throw away three or four?
froggit Wrote:Read my previous reply about ZFS to get an idea of how easy it is to use and setup, and the data safety mechanisms built in. You can look at parity data a bit like insurance: have no parity data and you lose data when drive(s) die, have parity data and your loss is zero to low, depending on how much parity data you have and how many drives die. It's not rocket science. Once this is understood well, one can plan the level of safety required.
I DO have parity data. I am willing to use one disk to store parity for all of my disks. So if I have 15 data disks I am using ONE parity disk. If you do this with ZFS and lose two disks what's left? If you are not left with 14 perfectly good ready to go disks then I'm sorry I see that as a disadvantage. Losing an entire array because I've surpassed the amount of party disk space I was willing to sacrifice is not in my best interest....
- BLKMGK - 2010-10-15 08:23
darkscout Wrote:I finally got unRAID running running on VirtualBox (no small feat since mlabel c:UNRAID would add random glyphs to the end "UNRAIDNonstandard setup, skip the bitching.". So I had to do label X, edit the bzroot to mount LABEL=X, etc).
darkscout Wrote:I can't explain how unimpressed I am.You missed the beta label?
I'm running "version: 5.0-beta2."
Under AFP & FTP it lists "Coming soon!". So there goes my TimeMachine backups.
darkscout Wrote:When adding a user I can't specify the UID, so NFS... well must just be global read/write (I'm on my XP laptop at work so no proper NFS).Create a folder at root and set it as a share. RTFM
(I know you can do "user shares") but by default all I see are "disk1" and "disk2" folders.
darkscout Wrote:I swapped out one of my virtual 10GB drives for a virtual 20GB drive (The scenario you keep repeating). I instantly got the error "Stopped. Disk in parity slot is not biggest." "If this is a new array, move the largest disk into the parity slot. If you are adding a new disk or replacing a disabled disk, try Parity-Swap." Except I can't find the Parity-Swap button.RTFM, parity drive must be as big or bigger than all other drives. Why don't you start with a 2TB parity and 2 10gb and start swapping data drives.
darkscout Wrote:I also notice that all my data isn't there. Isn't the parity drive just supposed to the missing data? I mean with ZFS I just do a disk swap and I have full coverage, in the mean time NONE of my data is missing.Eh?
I can yank single drives from my system all day and still see the data <shrug>darkscout Wrote:Fine. Power down. Put the 20GB drive into the parity disk slot... still have only 20GB available (disk1 & disk2).Umm yeah, you didn't add a larger data disk did you?
darkscout Wrote:At which point I get the fun message "WARNING: canceling Parity-Sync will leave the array unprotected!" For another 37 minutes. Meaning if a drunk driver hits a power line, neighbor digs into his power, who knows what else could happen: my data is unprotected.
Lol, yes if you stop the array from creating parity then it cannot protect the data. Novel concept, the server software doesn't have ESP. Does ZFS have no process for preparing a disk or recovering when a new drive is inserted in place of a failed one?
darkscout Wrote:The Free version only supported 2 disks (3 if you count parity). Free version of NexentaStor supports up to 12TB.Your point? The developer chose a different path for his paid version. <shrug>
darkscout Wrote:I suppose if I wanted to slap a bunch of drives in a case and have a NAS for unimportant stuff, maybe... then again I'd have to pay for using more than 2 drives. So I'd go with FreeNAS.... at which point I'd just use ZFS.
Ah so this was your conclusion before you started and you looked for ways of producing results to support it. You're right, those of us who chose this system were obviously somehow stupid and couldn't see all of these failings you're finding.
- BLKMGK - 2010-10-15 08:31
PANiCnz Wrote:I hate to fire up an already heated debate but everyone also seems to be ignoring the performance benefits that ZFS has, especially with coupled with ARC and L2ARC. When researching unRAID I'm pretty sure its widely acknowledged performance isn't great.
I think its might just be a case of us three being the only ones who've taken the time to read all the ZFS articles on the net and fully understand them.
I agree that ZFS realtime checking to guard against bitrot is probably one of its biggest selling points, until you've seen a few hundred gigs of data slowly corrupt without your knowledge you won't truly appreciate it.
unRAID is just JBOD with parity, I guess it serves its purpose.
Performance is fine now that SAMBA is faster. I can stream my movies on 100meg ethernet and they are high bitrate HD so how much bandwidth do you really need exactly? I know I saw a serious performance DECREASE when I put one of my unRAID boxes on a 100meg segment. Upgraded the segment to Gig ethernet and I saw my speeds back to normal. I can stream multiple HD movies at once without issue. Since movies, music, and backups are what my servers are used for I see no reason to use a system that parallelizes the disks. I'm not running an enterprise sized database or SAN here. I guess saying unRAID performance isn't "great" depends on what you are comparing it to and what it is you NEED.
