Adding drives to RAID 5 array or use Windows 8 Storage Spaces?

[chris_huh]

Hi,

I've been a bit confused about RAID and other hard drive options so am looking for a little clarity. I have an HTPC currently with two 3TB drives with Windows 8 installed onto a separate SSD.

Now what I'm trying to get is some sort of large volume which I can add to. So I currently have those 2x3TB drives but will certainly want to add to them (i have space for 6 or 7). I think something like a RAID5 array would be best, but I was under the impression you couldn't expand RAID5 arrays with additional drives. Is that correct?
(I understand I'm going to need to get at least one more HDD to bring the total to 3)

Even if it can my motherboard can only do raid 0 or 1 so I would probably just use software RAID.

So i suppose my question is: Can I expand RAID 5 software arrays in Windows 8? If not can I do that with these new Storage Spaces?

If I can't expand storage I guess the only way is to backup onto other drives and then restore back onto a newly created RAID array. This just sounds expensive.

Thanks

 

[Automata]

You can expand RAID arrays, yes. But, whether the feature is available or not comes down solely on the RAID controller or software. To do RAID 5, you would need at least three hard drives.

I don't know much about Storage Spaces, since I don't use Windows as my main operating system, but it does seem to fit the definition of what you want. It provides fault tolerance by using multiple drives and you can expand on it by adding drives.

http://www.techspot.com/news/46943-windows-8-adds-raid-like-storage-pooling-and-fault-tolerance.html

 

[chris_huh]

So i've got myself a third 3TB drive. Then I set up a Storage Space with parity, which is essentially a RAID 5 array, i think. This gives me 6TB storage with 3TB parity, but it's excruciatingly slow. I'm getting write speeds of less than 10MB/s, with read speeds only a little better.

Would I get similar speeds when using a RAID 5 controller PCI card?

I was at first put off by hardware RAID as the cards seemed expensive, but then i found this one: http://www.ebay.co.uk/itm/320895315395?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

[Automata]

That isn't a real hardware RAID controller. It does all the parity calculations on the processor. Basically, it is cheap junk.

Those write speeds seem far too slow, even for software RAID. Have you looked online to see if anyone is getting similar speeds?

 

[chris_huh]

I thought it seemed a bit too cheap.

I've looked around and found some articles and forum posts about slow Storage Spaces parity transfer speeds. So it seems to just be a problem with the way Storage Spaces implement the data parity.

Do you know of any third party software solutions to this that would offer RAID 5 at a more reasonable speed?

 

[chris_huh]

It might be worth mentioning that the data i am copying over is very large. So at the moment i am restoring the backup i had made of several TBs of video files. Some as big 18GB, but most probably around 1GB. I'm not sure if that makes too much difference when it comes to transfer speeds.
When i backed up from my RAID 0 array i was able to copy off at about 80MB/s.

I haven't been able to find anything about any good RAID 5 software packages so i guess it probably isn't possible. I think I'll stay with the Storage Spaces for now but if that really becomes unusable I might just go to a RAID 1+0 setup or similar.

 

[jason4207]

What kind of hardware are you running?

If you want to keep the array local to that PC your options are more limited. Have you thought about building a dedicated server?

What all is going in this array? If it's just movies and you just want to play them back there may be simpler options.

If you need fast write speeds a lot while you work you could use a cache drive. Do your work and then copy the contents over to the Storage Space overnight while sleeping.

 

[Automata]

It might be worth mentioning that the data i am copying over is very large. So at the moment i am restoring the backup i had made of several TBs of video files. Some as big 18GB, but most probably around 1GB. I'm not sure if that makes too much difference when it comes to transfer speeds.
When i backed up from my RAID 0 array i was able to copy off at about 80MB/s.

Anything over a few megabytes is going to give similar performance, so it doesn't matter of the file is a gigabyte or fifty terabytes. The server can only process information as fast as it is being fed or as fast as it can process.

Please clarify on the second part of your comment. You were able to to copy off at 80MB/s to what? If you were backing up to the server and those files have parity, then there is another issue. Software RAID should be capable of way more than 10MB/sec.

 

[chris_huh]

Hi,

Basically this is for an HTPC. It was originally in more of a media server machine; ie, just sitting on the network streaming the files to other clients, but I moved it into a dedicated HTPC server case and now sit it under my TV with XBMC used as the media player.

I have an ASUS m5a78l-m motherboard, AMD Athlon II X3 450 3.2GHz CPU, 4GB RAM, 1GB ASUS HD 6450 GPU. OS (Windows 8) is on a 64GB SSD and then I have 3x3TB HDDs (with space for another 3).

The HTPC is pretty much just videos (films and TV), perhaps i will put music on there too at some point but there is not urgency for that. I use XBMC to play videos and also have plex for streaming to other devices, a shared folder to access the files from my laptop, and run SABNZBd+, etc for downloading some things and MakeMKV etc for ripping my dvds and blurays.

I have noticed since moving over to this Windows 8 Storage Space with parity that sometimes sharing over the network can stutter, and when first starting up the HDDs seem to take a little longer to spin up (maybe a minute or more). Also it seems to take longer to rip discs and process downloads.

To clarify the write speeds. What I meant was when i backed up onto two external hard drives (one usb3 and one usb2) from my RAID 0 array I was getting 80MB/s but then after i reformated that RAID 0 array into a Storage Space with parity and copied back onto it (form the external HDDs) I was getting less that 10MB/s. I have heard (after i formated it all, of course...) that Storage Spaces are very slow when running with parity.

I'm starting to think that if I can't get RAID 5 much faster without shelling out any more cash I may just redo it as a Storage Space without mirroring or parity. I may not have a backup but it is only holding ripped, and sometimes downloaded, videos, which can always be reacquired.

Can you think of any other options?

and thanks

 

[Automata]

Before I get to the rest of my post, I want to clarify on a very important point. RAID is not a backup. Don't get these mixed up or you will be in for a huge headache when something goes wrong.

I haven't had the change to test out Windows 8 Storage Spaces in my NAS review series, so I'm unsure how it performs on my own hardware. I may bump this up in the priority list since it was recently released, however.

Storage spaces is not RAID 5. It may be like RAID 5 in that it offers parity, but it is not the same thing. If you were to go with software RAID, I think you would have much better performance. Since this is now your HTPC, I'm not sure how comfortable you would be moving to Linux. Mdadm (or ZFS) sounds like it would be substantially better for storage. Or, it may be worth it to see if Windows 8 will let you do RAID 5 directly from the operating system. I know that certain versions of Windows 7 would.

 

[chris_huh]

I may have used the term backup incorrectly before, sorry. What i understand RAID provides is if one of the HDDs fails you still have a version of the data available on a secondary HDD. Is that right? It doesn't help if you go and delete some files and then realise you want them again, but if there is a hardware issue it will help you out?

I did have it set up with linux, and have used it before. I moved over to Windows 8 specifically to make use of the Storage Spaces thing as I liked the idea that you could just add HDDs as you went along without needing to start afresh, like you have to in some RAID setups. I was also able to set up the HTPC to work perfectly with file sharing, IR remote controls, video performance, downloads, ripping, etc in about 2 hours whereas it had taken me about a week (on and off, admittedly) to get linux to the same state, except for ir functionality, which never worked.

I did dabble in some mdadm use and it seemd to work ok, but as i said before on of the main things i want to be able to do (sorry if i didn't mention it before) was to have the ability to add new hard drives to the existing volume without needing to start anew. Storage Spaces provides this and looked to work pretty well, ie good read/write speeds, with an equivalent RAID 0 or RAID 1 volume (ie mirror or stripe). It just stumbled at the parity one.

If you know of any software RAID 5-like system that works well i could use in windows that would be great, and I might give that a go. Otherwise i am tempted to ignore any sort of mirroring as it isn't necessarily vital data. I had a look in Computer Management in Windows 8 and I can't see any RAID 5-like function; only the Storage Spaces.

Thanks for your input

 

[Automata]

RAID protects against hard drive failure, to put it simply. If you deleted or modified a file on the array, it instantly propagates to all of the disks and there is no way to get back the old version.

Mdadm does allow expansion of RAID arrays (scroll down) without destroying the array and rebuilding it.

Beyond mdadm/ZFS, I don't have any further suggestions.

 

[chris_huh]

Ok, well thanks for your guidance, I have a better idea of the options now.

I'll have to work out my options.

Thanks again

 

[jason4207]

Look at FlexRAID. It runs under Windows and is very "flexible". LOL!

It can give you RAID5, RAID6, or RAIDn like parity protection.