[Aryn Ravenlocke]

While I was sitting down trying to price out everything for the new media server I am building for the house, I was asked what should have been a very simple question, "Why am I looking at solutions such as unRAID and FlexRAID for my server instead of simply using Windows 8.1's built-in software RAID application?"


I found that I didn't have a very good answer to that question. The only answer I could muster up was that I was looking into the other options instead of the built-in Windows solution because no one that I have spoken to that has a media server uses the Windows option. Is it simply because Windows 8/8.1 is still relatively new? Or are there some compelling reasons to use an alternative such as unRAID or FlexRAID?

 

[Kelson]

I know nothing about Win 8.1 RAID, but as you research it pay attention to the requirements for drive size. Most continuous RAID solutions require all the drives of the array to be equivalent size. A software RAID system like FlexRAID is more flexible and will allow you to add drives of any size to the array. The drives can maintain their individual identities or clusters of physical drives of various size can be aggregated at the OS level into a collection of single volumes. The only proviso is that the size of the parity drive(s) be equal to or greater than the largest size data drive (volume) in the array.


Another thing I would pay attention to is performance. An OS-based RAID, like a hardware RAID, is going to be a continuous RAID to offer maximum protection for data. Every time you write to the array there will be additional overhead of immediately updating the parity drive. Since this all has to happen in software driven by your CPU there will likely be a performance hit especially with write-intensive operations. A software RAID like FlexRAID is generally configured as a non-continuous RAID -- I/O operations to the HDD's occur normally without the overhead of continuously updating the parity disk. The parity disk is updated on demand or scheduled to do so at night when the system lays fallow. This could be a disastrous situation for systems handling live business data but is very nicely suited to a Media server which takes in data infrequently and in chunks and spends most of its time serving data. In that case a nightly update of the parity drive is more than sufficient or if you have just spent several hours ripping and uploading several disks you could manually trigger a parity update when done if it makes you feel better.


There are probably other limitations on the use of OS-based software RAID vs Flex RAID that your research will reveal.

 

[funhouse69]



Quote:
Originally Posted by Aryn Ravenlocke  /t/1525985/windows-8-1-software-raid#post_24572226


While I was sitting down trying to price out everything for the new media server I am building for the house, I was asked what should have been a very simple question, "Why am I looking at solutions such as unRAID and FlexRAID for my server instead of simply using Windows 8.1's built-in software RAID application?"


I found that I didn't have a very good answer to that question. The only answer I could muster up was that I was looking into the other options instead of the built-in Windows solution because no one that I have spoken to that has a media server uses the Windows option. Is it simply because Windows 8/8.1 is still relatively new? Or are there some compelling reasons to use an alternative such as unRAID or FlexRAID?

Windows 8 adds something called "Storage Spaces" which allows you to pool your drives together in to one large drive, you can remove / add drives as you like. This is kind of like FlexRAID. You can also add in some level of redundancy as well.

 

Here is some info directly from the Mothership http://windows.microsoft.com/en-us/windows-8/storage-spaces-pools

 

Keep in mind that this is not "New" this is something that Microsoft offered in their Home Server Product (which has been discontinued) but was called something different like Drive Pools. At First it was somewhat of a disaster but over the years they have worked out all of the bugs and now even offer it in some of their server solutions like Server 2012. It is worth taking a look at. While I am not a huge fan of windows 8, I think that 8.1 is worth taking a look at. I would play with it and see if it meets your needs. I don't think you will run in to any performance issues if you have a relatively new processor like the Core I3, 5 or 7's. Unless of course you are doing something like transcoding multiple streams for Plex or something like that.

 

My suggestion would be to play with it and see if it works the way you want it to by doing some testing, copy data / remove drives and see how it deals with it. From what I am hearing it is pretty robust and works really well. That said there is NO way that any single solution can prevent data loss, it is always wise (but sometimes cost prohibitive) to have a backup.

 

[mlknez]

Storage pools works very well. I have 49TB in it right now. I have had 2 different drive failures and storage pools hasn't missed a beat.

 

[Mark_Venture]

I had tried using other "free nas" solutions, but had problems using the WD Green drives I had on hand.


So I tried using Storage Spaces in Windows Server 2012 Basics on a Core2Quad Q6700/Intel DG33TL/6gig ram system. Its the same as Storage Spaces in Windows 8/8.1. It was easy to setup and start using. It worked with the WD Green drives I had already on hand.


A few things to keep in mind if you want to use a "Parity" (aka striped) set which is similar to raid 5.


If you are setting up a parity set, you will assign "columns." When you add disks later, you can't rebalance the data. So, start with a 3 drive parity set using 2TB drives, it will be setup as 3 columns. Fill it up so there is 50gig left on each drive. When you add the fourth 2TB drive to the set, the first 3 drives still show 50gb free, and the 4th shows completely free. As you write data, you'll fill up the first 3 disks, and be told the space is full, even though the 4th disk has free space. Your supposed to add disks in based on the number of columns. So if columns = 3, you need to add 3 disks when increasing the pool. To get around this, as I was adding one disk at a time, I had to move the data off, remove the pool, add the new disk, recreate the pool using all disks, then move the data back. What a pain!! I suggest you start with the maximum number of disks you can if you are going to use parity configuration, or plan upgrades ahead due to columns!


When using a parity set, because of the "space" issue, don't use dissimilar sized disks. Using a 500gig drive mixed with 1TB drives will limit you, since the 500gig drive will fill up first.


Once the pool is full, it goes off line. I've only read about this as I've kept an eye on free space. From what I found, if this happens, you can bring it back online by making it read only. I do not know how to get to a state where you could delete something to make it R/W again, but at least your data isn't lost.


Read/Write speed isn't bad. Is it near "hardware raid'? I don't think so, but I don't have anything to compare with. Using five older 2TB WD Green drives connected t the DG33TL's onboard SATA controllers, and a pool configured as parity, I would average 50-70mb/s transfers when moving files from my i7-860 machine across gigabit Ethernet to the pool. I would sometimes hit 90-100mb/s range, but it wasn't often. I just went through the exercise of replacing the 2TB's with six 4TB WD Red drives, however I have to use a PCIe X2 card to gain additional SATA ports to connect all the drives and the boot drive. The file transfers is a little slower now. I have to see if I get all 6 WD's on the on-board controller if gets better (i.e. see if the PCIe controller is the limit).


If the board or controller dies, its ok. the pool can be moved to another system and accessed.


In testing, my parity setup does seen to survive a single drive failure (which is the main reason I'm doing this). I tested by setting up a pool, putting data on it, and removing one drive's power cord. Data was still able to be read. I did not try writing. After re-attaching the power cord, the pool reported healthy and was working fine.


Is it better or worse than other options out there? I don't know because the other options I tried I had problems getting working, but this works. There are plenty of articles on Storage Spaces and Storage Pools on Windows Server 2012 and Windows 8.0/8.1 out there which describe it as anything from horrible to OK.


So far its been working fine for me.


If you have the time, its worth giving it a try to see how it works for you.


My "server" has windows shares that my LG BD390 and BD570 bluray players access to natively play MKV files created by BD-Rebuilder (no transcoding or DLNA needed). I also have it running PS3Media Server and Serviio to transcode/stream the MKV's to my two Sony TV's and my PS3. In this configuration, the sever still handles streaming while my wife/son watch downstairs and I watch upstairs, even when transcoding was used.


Oh, and I haven't tried setting up Simple or Mirrored spaces, only Parity.

 

[Aryn Ravenlocke]



Quote:
Originally Posted by Mark_Venture  /t/1525985/windows-8-1-software-raid#post_24574966


I had tried using other "free nas" solutions, but had problems using the WD Green drives I had on hand.


A few things to keep in mind if you want to use a "Parity" (aka striped) set which is similar to raid 5.


If you are setting up a parity set, you will assign "columns." When you add disks later, you can't rebalance the data. So, start with a 3 drive parity set using 2TB drives, it will be setup as 3 columns. Fill it up so there is 50gig left on each drive. When you add the fourth 2TB drive to the set, the first 3 drives still show 50gb free, and the 4th shows completely free. As you write data, you'll fill up the first 3 disks, and be told the space is full, even though the 4th disk has free space. Your supposed to add disks in based on the number of columns. So if columns = 3, you need to add 3 disks when increasing the pool. To get around this, as I was adding one disk at a time, I had to move the data off, remove the pool, add the new disk, recreate the pool using all disks, then move the data back. What a pain!! I suggest you start with the maximum number of disks you can if you are going to use parity configuration, or plan upgrades ahead due to columns!

Thanks for the heads-up on the column issue. I have yet to see that anywhere in the documentation that is floating around. Since I have a PC with Windows 8.1 on it already, I figured I would just fiddle around with Storage Spaces while I continue to work out the rest of the details for my home media server.


I have a question about the columns though, and I don't have enough empty drives to test this myself. When setting up your columns initially, does parity automatically simply assign as three columns? The reason I ask is because, the external enclosures I have been looking at (other than Synology which I am still heavily considering) are mostly 8-drive enclosures. Inserting drives in multiples of threes obviously is not ideal in this situation. I had planned on starting with two 8-drive enclosures, one for movies and one for television, both with 6x 4 TB discs in them, using parity. I figured that would leave me roughly 18 or so TB in each enclosure after parity and overhead. The problem becomes, if I must add three discs to expand the pool in the future, neither enclosure would be able to handle all three drives.


Your suggestion was to start with the maximum number of discs possible. Does this mean I should just start with both cases filled to capacity with 8x 4 TB drives? My one concern with this is that there is a real possibility that in the next 2 years or so, I could fill the enclosure dedicated to movies. If I need to match the original number of drives in the initial build for the pool, that would mean having to purchase another 8 drives to add any space at all, while I am likely to only need the equivalent of about 1 - 2 TB/ year after.

 

[Mark_Venture]

I used the example of 3 disks because, like Raid5, you need a minimum of 3 drives when setting up Parity, and it sets the number of columns equal to the number of drives. So 3 drives = 3 Colums, so expansion must be 3 drives at a time. This might help -> http://social.technet.microsoft.com/wiki/contents/articles/11382.storage-spaces-frequently-asked-questions-faq.aspx#What_are_columns_and_how_does_Storage_Spaces_decide_how_many_to_use


I suggest using the max number of drives at the initial build time, because in my case I started small, with 3 drives, and only had the budget to add one drive at a time which caused me headaches to expand. (i.e. backup the data, break the pool, recreate it, put the data back). I have not tested the scenario of setting up a 3 drive pool, then expanding by adding 3 drives later, maybe that is easier?


As for 6 x 4TB drives, yes, 18.1TB when setup at the same time as parity. But if you start with 6, and want to expand later, you'll have to add 6 drives. (when setup, 6 drives = 6 colums, so when you expand, you'll need to add 6 drives).


I also didn't play with it enough to determine how much space is lost to parity when you expand by adding drives . Example, capacity when using the first group of drives is N-1, so setting up 3x 2TB drives would be 3 columns, ~4tb data and ~2tb parity... when you expand you need to add 3 drives, which I assume would be again ~4TB data and ~$2tb parity giving you a total of 8TB data and 4TB parity, where as I know if you build with 6x2TB drives it would be 6 Colums, ~10TB data and ~2TB parity.




Here are a few links that I was reading before I tried it...

http://www.bleepingcomputer.com/tutorials/how-to-configure-storage-spaces-windows-8/
http://arstechnica.com/information-technology/2012/10/storage-spaces-explained-a-great-feature-when-it-works/
http://windowsitpro.com/windows/navigating-storage-spaces-and-pools
http://betanews.com/2014/01/15/windows-storage-spaces-and-refs-is-it-time-to-ditch-raid-for-good/

 

[Aryn Ravenlocke]

I appreciate the input, and the links. I had read two of those while I was trying to learn what the heck Storage Spaces was after I was asked, "Why not use Windows?" When I was reading it though, it seemed to me that, although columns are usually identified 1:1 with the number of physical drives in the initial setup, that the user could assign less columns than total drives, it would merely result in slower write speeds. If that's the case, Couldn't I start with a full 8-disk case, but when creating the spaces, tell it only to make four columns? This would still be one drive more than necessary to run Storage Spaces in parity mode.

 

[Mark_Venture]

Yes, you could physically install 8 disks and add them to the pool/virtual disk 4 at a time to keep the columns at 4.

 

[Mark_Venture]



Quote:
Originally Posted by Mark_Venture  /t/1525985/windows-8-1-software-raid-storage-spaces#post_24574966


...Read/Write speed isn't bad. Is it near "hardware raid'? I don't think so, but I don't have anything to compare with. Using five older 2TB WD Green drives connected t the DG33TL's onboard SATA controllers, and a pool configured as parity, I would average 50-70mb/s transfers when moving files from my i7-860 machine across gigabit Ethernet to the pool. I would sometimes hit 90-100mb/s range, but it wasn't often. I just went through the exercise of replacing the 2TB's with six 4TB WD Red drives, however I have to use a PCIe X2 card to gain additional SATA ports to connect all the drives and the boot drive. The file transfers is a little slower now. I have to see if I get all 6 WD's on the on-board controller if gets better (i.e. see if the PCIe controller is the limit). ....

And I just got a chance today... I connected the six WD Red's to the SATA ports on the mother board, and moved the boot drive to the PCI-E card.


I have to do more testing. I moved a 3gig file from the WD Black drive in my primary PC across the network to the pool and I got 90-100MB/s (as reported by the file copy dialog box in windows). But when moving a folder containing a blueray backup (contains large and small fixes) from my Seagate 7200.14 to the pool, its in the 40-50MB/s range. I wonder if this seagate drive in my primary PC is the bottleneck, not the pool?

 

[funhouse69]



Quote:
Originally Posted by Mark_Venture  /t/1525985/windows-8-1-software-raid-storage-spaces#post_24583091



And I just got a chance today... I connected the six WD Red's to the SATA ports on the mother board, and moved the boot drive to the PCI-E card.


I have to do more testing. I moved a 3gig file from the WD Black drive in my primary PC across the network to the pool and I got 90-100MB/s (as reported by the file copy dialog box in windows). But when moving a folder containing a blueray backup (contains large and small fixes) from my Seagate 7200.14 to the pool, its in the 40-50MB/s range. I wonder if this seagate drive in my primary PC is the bottleneck, not the pool?

I assume the speeds you are talking about are through a Network Connection? If you are seeing 90-100MB / Sec then you are in really good shape as that is pretty much saturating a Gig Network connection. Remember that a Network is in "Bits" not "Bytes" so 125MB/Sec is the theoretical limit but in real world with overhead you are lucky to see 110 MB/Sec. Another way to test the performance of a file copy is if you have a fast USB 3 Drive and of course it is connected to a USB 3 Port. I can see 225MB / Sec from my SSD to my 4TB External Drive.

 

Also smaller files will almost always slow down the transfer as the drive(s) might have to do a little (or a lot) more hunting for the files and can't pump out a continuous stream of data. Even the 40-50MB/Sec range is more than acceptable. When I copy to my Synology RAID large files I get 110MB / Sec solid, when I do something smaller like MP3's it goes down to about half that so the numbers you are quoting are right up there with a Synology RAID.

 

[Mark_Venture]



Quote:
Originally Posted by funhouse69  /t/1525985/windows-8-1-software-raid-storage-spaces#post_24590953



I assume the speeds you are talking about are through a Network Connection? If you are seeing 90-100MB / Sec then you are in really good shape as that is pretty much saturating a Gig Network connection. Remember that a Network is in "Bits" not "Bytes" so 125MB/Sec is the theoretical limit but in real world with overhead you are lucky to see 110 MB/Sec. Another way to test the performance of a file copy is if you have a fast USB 3 Drive and of course it is connected to a USB 3 Port. I can see 225MB / Sec from my SSD to my 4TB External Drive.


Also smaller files will almost always slow down the transfer as the drive(s) might have to do a little (or a lot) more hunting for the files and can't pump out a continuous stream of data. Even the 40-50MB/Sec range is more than acceptable. When I copy to my Synology RAID large files I get 110MB / Sec solid, when I do something smaller like MP3's it goes down to about half that so the numbers you are quoting are right up there with a Synology RAID.

Yes, it is when copying across network connection... I use my primary PC for ripping and encoding... Then I copy the MKV to the server to watch, and the rip folder to the server to hold onto until I've watched the MKV and know its "good"


Here is a test I just did....



OS Drive.. WD 1TB Black (on PCIe X1 card SATA 3 card)....



CrystalDiskMark 3.0.3 x64 (C) 2007-2013 hiyohiyo

Crystal Dew World : http://crystalmark.info/



* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]


Sequential Read : 110.867 MB/s

Sequential Write : 107.823 MB/s

Random Read 512KB : 47.686 MB/s

Random Write 512KB : 67.250 MB/s

Random Read 4KB (QD=1) : 0.709 MB/s [ 173.1 IOPS]

Random Write 4KB (QD=1) : 1.684 MB/s [ 411.1 IOPS]

Random Read 4KB (QD=32) : 1.921 MB/s [ 469.1 IOPS]

Random Write 4KB (QD=32) : 1.709 MB/s [ 417.2 IOPS]


Test : 1000 MB [C: 5.2% (48.8/931.2 GB)] (x5)

Date : 2014/04/13 8:57:22

OS : Windows Server 2012 Server Standard (full installation) [6.2 Build 9200] (x64)



Storage pool of six 4TB WD Red drives connected to the DG33TL's onboard SATA2 controller ports...



CrystalDiskMark 3.0.3 x64 (C) 2007-2013 hiyohiyo

Crystal Dew World : http://crystalmark.info/



* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]


Sequential Read : 384.235 MB/s

Sequential Write : 31.212 MB/s

Random Read 512KB : 50.959 MB/s

Random Write 512KB : 16.855 MB/s

Random Read 4KB (QD=1) : 0.778 MB/s [ 190.0 IOPS]

Random Write 4KB (QD=1) : 1.637 MB/s [ 399.6 IOPS]

Random Read 4KB (QD=32) : 6.341 MB/s [ 1548.2 IOPS]

Random Write 4KB (QD=32) : 1.713 MB/s [ 418.2 IOPS]


Test : 1000 MB [F: 47.6% (8869.4/18619.9 GB)] (x5)

Date : 2014/04/13 9:28:22

OS : Windows Server 2012 Server Standard (full installation) [6.2 Build 9200] (x64)



Part of me wants to put the Green drives back, just to test and compare... But I don't have the time, and it would be a little bit of a headache.