News - Microsoft introduces 'Storage Spaces' for Windows 8

[HEXUS]

Spaces (virtual disks) and Storage Pools (collections of USB, SATA and SAS drives).

Read more.

[wesleyaldred]

Makes a change, actually looks like Microsoft did something quite useful !

[shaithis]

Looks like the system they had in Home Server. I am sure some people will be very happy to see it's return.

[RedFlames]

So this looks like the replacement for Drive Extender

edit: beaten to it by shaithis

[Ross1]

Essentially the parity sounds quite similar to ZFS or flexraid, or unraid. From what I can gather, the mention of raid 6 seems..... wrong.

[kingpotnoodle]

Optionally, the user can specify either 'Mirrored' or 'Parity' data protection for each space.
For 'Mirrored' this results in either a RAID 0 or 10-like storage solution depending on whether the user selected two or three-way mirroring and the number of drives in the pool - this solution is faster but requires more space.

Somebody needs to go and revise RAID levels by the looks of it.

RAID 0 = Striped, no redundancy.
You mean RAID 1 if it's a mirror.
You can't make a RAID 10 with 3 drives, it needs an even number.

Something doesn't add up, unless there is some bizarre matrix arrangement here.

Also RAID 6 is double parity, as in capacity = n-2, and this requires 4 or more drives. I suspect you really mean RAID 5?

[Scribe]

Somebody needs to go and revise RAID levels by the looks of it.

RAID 0 = Striped, no redundancy.
You mean RAID 1 if it's a mirror.
You can't make a RAID 10 with 3 drives, it needs an even number.

Something doesn't add up, unless there is some bizarre matrix arrangement here.

Also RAID 6 is double parity, as in capacity = n-2, and this requires 4 or more drives. I suspect you really mean RAID 5?

Ah that's me mixing up RAID 0 and RAID 1 =P Sorry - it was relating to an FAQ on performance that I had been reading that referred to RAID 0 - corrected now. I never did say you need 3 drives for RAID 10 though and regarding RAID 6 comment I was comparing to RAID 6 as you can suffer up to two drive fail-over with the new Windows solution, not saying that the solution actually is RAID 6 as it's not RAID at all but behaves in a similar manner, I'll assume that the solution scales to single parity over three disks but there're no details in the post referring to the minimum number of drives and what level of fail-over so I can't be certain so I've clarified to say 5/6.

[[GSV]Trig]

Wonder if they will remove this with Windows9...

[kingpotnoodle]

I never did say you need 3 drives for RAID 10 though

For 'Mirrored' this results in either a RAID 1 or 10-like storage solution depending on whether the user selected two or three-way mirroring and the number of drives in the pool - this solution is faster but requires more space.

I did a bit more research...

Steve Sinofsky's blog (http://blogs.msdn.com/b/b8/archive/2...fficiency.aspx) says:

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 optimized for minimized user complexity, maximized flexibility in physical disk utilization and allocation, and fast recovery from physical disk failures.

So really any mention of RAID 1 is erroneous, it's never just a straight mirror, there is always some "striping", deep down seems that really comparison with any traditional RAID is rather flawed, it's not that close to a RAID 10, there are different requirements to numbers of disks and arrangement of data.

In the new mirroring scheme disks are divided into 256MB 'slabs', depending on whether 2 or 3 way is selected a slab is copied onto 1 or 2 extra drives from the pool (so 3 way require 3+ drives, 2 way requires 2+ drives). It's not like RAID in that it's not symmetrical, if you have 7 drives then the 2 or 3 slabs could be on any of them but it looks like Windows tries to spread slabs evenly over disks to balance the load.

[kingpotnoodle]

Parity spaces will only survive failure of a single physical disk backing the parity space – note, however, that concurrent failures of other disks within the pool not backing the parity space do not impact access to the parity space.

A MS employee has answered that, so it's definitely analogous to RAID 5 and not 6.

[iamlorro]

looks useful if you want to set and forget about stuff, and for built in resiliency.

not used the original WHS, so no experience of this.

Quite looking forward to win 8 - seems to be a good amount of improvements coming out via the blog.

[jim]

It's a totally different system to WHS by the looks of it. There's a reason they dropped support for drive extender.

WHS didn't stripe or anything like that, it just made a duplicate of every single file, and ensured that one copy was on one physical drive, and another copy was on another physical drive. It operated on top of standard NTFS drives.

[Scribe]

A MS employee has answered that, so it's definitely analogous to RAID 5 and not 6.

Noted, updated the post, thanks.

[Scribe]

In the new mirroring scheme disks are divided into 256MB 'slabs', depending on whether 2 or 3 way is selected a slab is copied onto 1 or 2 extra drives from the pool (so 3 way require 3+ drives, 2 way requires 2+ drives). It's not like RAID in that it's not symmetrical, if you have 7 drives then the 2 or 3 slabs could be on any of them but it looks like Windows tries to spread slabs evenly over disks to balance the load.

Yeah, this is why I'm comparing to RAID only in the sense of how it protects the data, if there was a 1:1 relationship then it wouldn't be possible to handle multiple and dynamically sized Storage Spaces.

[mikerr]

Great, bringing RAID-like redundancy down to average user, and using USB drives.

Not sure I see the point of pre-setting the maximum capacity (especially at more than the drive capacity),
surely that just makes it confusing to see how much space you currently have left ?

While it says this allows mixed size hard drives, I'm not sure how the redundancy/parity would work:

Say I have 2x 1TB drives and a 3TB drive in a pool.

Best I can see is that there'd be a max of 3TB usable space, losing the capacity of the largest drive ?

[Apex]

So this looks like the replacement for Drive Extender

edit: beaten to it by shaithis

Sure looks like a newer version of DE to me...... now we might now know why MS killed for the 2nd release of Home Server; if they do another version based on the windows 8 codebase it could prove the selling point.