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Windows 8 to get RAID-like 'Storage Spaces'

Windows 8 to get RAID-like 'Storage Spaces'

Windows 8 will include Storage Spaces, a RAID-like system born from Drive Extender.

Microsoft has confirmed that the sadly defunct Drive Extender functionality first seen in Windows Home Server is coming back bigger and better, in Windows 8's Storage Spaces functionality.

Unveiled late last week by Rajeev Nagar, a group programme manager on Microsoft's storage and file system team, Storage Spaces is a new replacement for Drive Extender, offering much of the latter's functionality with increased performance and new flexibility.

'In a nutshell," Nagar explains, 'Storage Spaces allow: organisation of physical disks into storage pools, which can be easily expanded by simply adding disks; and usage of virtual disks (also known as spaces), which behave just like physical disks for all purposes.'

Drives connected to a storage pool can use almost any connectivity into the host system: USB external drives, SATA internal drives and even enterprise-grade SAS (Serial Attached SCSI) drives are supported, while the virtual disks support thin provisioning and resiliency that makes RAID (Redundant Array of Independent Disks) unnecessary for most.

'Fundamentally, Storage Spaces virtualises storage in order to be able to deliver a multitude of capabilities in a cost-effective and easy-to-use manner,' adds Nagar. 'Storage Spaces delivers resiliency to physical disk (and other similar) failures by maintaining multiple copies of data. To maximize performance, Storage Spaces always stripes data across multiple physical disks. While the RAID concepts of mirroring and striping are used within Storage Spaces, the implementation is optimised for minimised user complexity, maximised flexibility in physical disk utilisation and allocation, and fast recovery from physical disk failures.'

The result, Nagar claims, is an easy to use storage infrastructure which is capable of scaling from a single disk to 'multiple hundreds of disks' while offering performance that is 'very competitive' with optimised RAID 0 or RAID 10 arrays.

Sadly, there are a few caveats: a Storage Space cannot be bootable, meaning users will need to set aside a separate drive or partition to act as their OS installation disk and boot medium. Additionally, despite its origins in Windows Home Server's Drive Extender technology, there's no way to migrate data between the two. Instead, users are told to create a new Storage Space and manually copy the data across from their old Drive Extender volumes.

Due to appear in Windows 8 and Windows 8 Server, drives configured for Storage Spaces won't be backwards compatible with older versions of Microsoft's operating system; for those who don't need compatibility, however, it could prove an interesting alternative to traditional RAID implementations.

More information on Storage Spaces, including some screenshots of the user interface and notification system, is available over on the Building Windows 8 MSDN blog.

23 Comments

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misterd77 9th January 2012, 14:04 Quote
first

then i took an arrow..well you know the rest
faugusztin 9th January 2012, 14:14 Quote
And they introduce this technology after i got the microserver with Windows Server 2008 R2, and after i just ordered Windows Home Server for the other server :(.
scott_chegg 9th January 2012, 14:20 Quote
If this appears in the home premium edition then it will be great. These are the kind of features us in the enterprise storage game have been using for years now.
badders 9th January 2012, 14:33 Quote
How does storage spaces compare to other forms of storage when it comes to Data Recovery - I take it you can't just grab a disk from a Storage pool and attach it to another PC to grab the data off?
yakyb 9th January 2012, 14:39 Quote
Not Overly convinced i want this but i can see where it would be useful
scott_chegg 9th January 2012, 15:53 Quote
Quote:
Originally Posted by badders
How does storage spaces compare to other forms of storage when it comes to Data Recovery - I take it you can't just grab a disk from a Storage pool and attach it to another PC to grab the data off?

Nope. The data is striped across all the disks in the pool so one disk out of the pool is useless without the other member disks. It'll work like raid in that it'll write data and parity info across all the disks so you can suffer a disk failure with out losing the data.
saspro 9th January 2012, 16:03 Quote
So they've put a pretty gui on the software RAID that's been in the server & pro OS's for ages?
scott_chegg 9th January 2012, 16:16 Quote
Kinda yes but it won't be like raid as you've known it before. It uses the concept of flexible storage pools instead of virtual raid volumes. All the latest gen enterprise storage systems are moving to this model now as you lose less raw storage to parity.

In an older SAN you would carve groups of disks out into RAID groups. e.g. a RAID 5 4+1 LUN in which you lose 1 disk to parity. If you do this across your entire SAN of say 96 disks your losing a heck of a lot of disks to parity.

In the new storage pool model all your disks are in 1 big pool so the parity overhead is much smaller. you can add disks to the pool and the existing data will be restriped across the new disks in the back ground to give you the maximum spindle count you can get and therefore the best performance.

Whether this does re-striping is left to be seen though.

It also mentions thin provisioning as a feature which is nice but does come with a slight hit on performance.
saspro 9th January 2012, 16:31 Quote
Hmmn. Similar to the newer MSA's then.
Providing they actually include those features & don't opt to reduce it to the old WHS method or just a GUI then I can see a use for it.
Risky 9th January 2012, 16:32 Quote
For those of you not familiar with WDE the big advantage over raid is that you don't need identical drives and you can add more storage at any time just by buying another disk at whatever capacity is priced well. With WHS1 I startd with 500Gb and then added 1.5TB when I needed more romm and later removed some of the500Gb for other uses.
steveo_mcg 9th January 2012, 16:44 Quote
Ah so its like Logical Volume Manager?
scott_chegg 9th January 2012, 16:46 Quote
Risky has hit the nail right on the head there. That is a great advantage. Just been reading the MSDN blog post. You can create different resiliency level spaces out of the same underlying disk pool. So you can create a mirrored reduncancy space, i.e RAID 1 and a distributed parity redunancy space, i.e RAID 5 out of the same disks. Nice!
edzieba 9th January 2012, 17:03 Quote
This is a LONG way from software RAID. It is pretty much ZFS without the deduplication and data integrity checking (and with a much nicer UI). At least, as far as I can glean from the blog post; it sounds like software can use the additional copies on other drives to parity-check files on demand, but data integrity is not an inherent feature of the filesystem.

It even has copy-on-write and journalling (with an option to assign the journal to an SSD)! Oh frabjous day!
Flibblebot 9th January 2012, 22:49 Quote
Welcome back, Gareth, glad to see you're going to be one of the freelancers :D

tbh, though, I can't see many people other than enthusiasts using this functionality - I wouldn't be surprised if it was only available in the Professional edition and not in the Home edition...
talladega 9th January 2012, 23:41 Quote
Amahi Home Server uses Greyhole Drive Pooling. I am going to be building a server using it.
Maybe one day when Windows 8 comes out I may try this, but the drive pooling in Amahi is pretty awesome. I did some testing with it and if your server crashes you can take any of the HDDs and plug it into any machine and read the data off it. It is not striped. It basically acts like JBOD but with folder/file level RAID where you can choose which files/folders you want duplicated and how many duplicates. Then you can choose who can read/write/view these files/folders.
mclean007 10th January 2012, 05:52 Quote
If they're going to do this, why not go the full ZFS way, with snapshots, automatic data integrity checking to identify data transmission errors and silent disk corruption, block level deduplication, priority resilvering of metadata first when rebuilding after drive failure (maybe it does this, the paper is unclear), etc.? To my mind, these features are the real "value add" elements of ZFS, and it seems a shame that Microsoft, having gone to the trouble of building a virtualised storage manager from the ground up, haven't seen fit to include them.

Cynically, I wonder if these are features that will be added in Windows 9 (hopefully with backwards compatibility so existing Storage Spaces can be migrated over) as an incentive to upgrade, or if perhaps they will be available only in professional / ultimate versions of W8, with a more pared down version (again hopefully cross compatible) available in the home versions.
Deders 10th January 2012, 07:49 Quote
So what's the difference between this and the Dynamic Disks that have been with us since Windows 2000 and possibly NT?
nmunky 10th January 2012, 10:32 Quote
I don't know if any of you guys had experience with the old Drive Extender system in WHS but for me it turned out to be a bit of a nightmare:

If you wanted to remove a disk from the array if it was old/slow/whatever it had to be checked and 'fixed' automatically before the data could be shifted onto other disks in the array prior to the drives removal.
Problem was that if there was anything seriously wrong with the disk WHS couldn't sort it out and you would be unable to safely remove the disk.
[The really annoying bit was Googling for technical help inevitably brought up a well known stationery chain.]

I spent weeks going round in circles with this problem before I finally removed all the disks and manually sorted out the files in a much more traditional primary/backup disk situation in plain old server 2003.

Give me old school RAID 5 anytime.
Risky 10th January 2012, 13:24 Quote
I ran a Raid 5 (on a from an Adaptec 2410SA) on a desktop and WHS with drive extender for several years.

The big problem with Raid5 was that you need to match the disk so you need to buy 4 identical drives (one as the spare) and end up with 2 drives worth of storage. then you're find until the card goes belly up (mine did). With DE you can migrate to larger drives incrementally.

I have have disk faults with WHS and in each case have been able to remove the drive after adding another drive to take the storage. My worst trouble was where I had errors in the system drive, which wouldn't be an issue in the Win 8 as they are not proposing to use ths on the system.
Wossack 10th January 2012, 13:59 Quote
Gave up on WHS when there was talk of them dropping Drive Extender - had been an avid fan for at least 2 years prior to that. Onto an always-on unraid setup for the past year now, and havent been happier

zfs was very tempting also
Risky 10th January 2012, 14:13 Quote
Quote:
Originally Posted by Wossack
Gave up on WHS when there was talk of them dropping Drive Extender - had been an avid fan for at least 2 years prior to that. Onto an always-on unraid setup for the past year now, and havent been happier

zfs was very tempting also


I stuck with WHS1. There are a couple of add-ons to put somethign similar in to WHS2 but I haven't time to upgrade at the moment.
Tyinsar 10th January 2012, 17:10 Quote
Quote:
Originally Posted by mclean007
If they're going to do this, why not go the full ZFS way, with snapshots, automatic data integrity checking to identify data transmission errors and silent disk corruption, block level deduplication, priority resilvering of metadata first when rebuilding after drive failure (maybe it does this, the paper is unclear), etc.? To my mind, these features are the real "value add" elements of ZFS, and it seems a shame that Microsoft, having gone to the trouble of building a virtualised storage manager from the ground up, haven't seen fit to include them.

Cynically, I wonder if these are features that will be added in Windows 9 (hopefully with backwards compatibility so existing Storage Spaces can be migrated over) as an incentive to upgrade, or if perhaps they will be available only in professional / ultimate versions of W8, with a more pared down version (again hopefully cross compatible) available in the home versions.
Pretty much what I was about to post. I had been looking into FreeNAS with ZFS for these features but ended up with a Drobo attached to a nettop as my server for the sake of flexibility and ease of administration. If this ends up with good data integrity checking it I suspect W8 will replace many Drobos and FreeNAS systems. The key, however, is data integrity (and the other features of ZFS would be nice too).
JohnDribble 20th July 2012, 01:29 Quote
Quote:
Originally Posted by scott_chegg
In the new storage pool model all your disks are in 1 big pool so the parity overhead is much smaller. you can add disks to the pool and the existing data will be restriped across the new disks in the back ground to give you the maximum spindle count you can get and therefore the best performance.

And on a rebuild with 96 disks in an equivalent to RAID 5 you're quite likely to get a URE and lose all your data.
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