If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
RAID 1 Mirror From Two SMB Devices?
Does any vendor sell software for Windows that would make a RAID 1 mirror
from two SMB NAS devices on the back end? Performance on NAS has gotten so good with gigabit ethernet that there is little reason to prefer SANs for most applications. What I would like to remove from the equation is the impact from a hardware failure of the NAS box itself. The built-in Windows Server mirroring, and the more advanced version of the same sold by Veritas, only want to work with devices that are seen as locally attached. I want to know if anyone makes similar functionality for SMB connected NAS devices. Having the same capability over the NAS abstraction would be quite powerful and useful. -- Will |
#2
|
|||
|
|||
RAID 1 Mirror From Two SMB Devices?
Will wrote:
Does any vendor sell software for Windows that would make a RAID 1 mirror from two SMB NAS devices on the back end? That would be a technical impossibility: NAS operates at the file level, while RAID operates at the disk-block level. Now, it would be possible to create a local file system that sent identical file-level updates to two NAS back-ends (and indeed I think that at least one of the recent 'file virtualization' start-ups does something of that sort, though using an intermediary rather than a local file system as the fork point - for reasons that may become obvious below). Performance on NAS has gotten so good with gigabit ethernet that there is little reason to prefer SANs for most applications. What I would like to remove from the equation is the impact from a hardware failure of the NAS box itself. It's not clear what you think you'd be gaining. First of all, you couldn't share the data on the NAS back-ends with other clients, because (by definition) the single client controlling the mirroring between them has no way to coordinate such sharing with others. So what you'd have is a client, using a local stub file system, to control two more private copies elsewhe why not just let the client file system directly control disks elsewhere (or, for that matter, locally-mirrored disks: if the client goes down it won't matter that the data remains accessible)? The built-in Windows Server mirroring, and the more advanced version of the same sold by Veritas, only want to work with devices that are seen as locally attached. The issue is not local vs. remote, it's file-level vs. block-level access. I want to know if anyone makes similar functionality for SMB connected NAS devices. Almost certainly not, since the possibilities for corruption (unless the NAS back ends where stringently protected from any access by other parties) would be rampant. The closest you're likely to find is a proprietary file system that uses proprietary protocols to access closed back ends: there are actually a couple of reasons one might want to do that, though hardly compelling ones (i.e., it might fall out as a useful side-effect of an implementation, but isn't something one would go out of one's way to implement). Having the same capability over the NAS abstraction would be quite powerful and useful. Not really. It does provide a level of device independence, but at the cost of a couple of additional levels of software (plus additional overhead ensuring that the back ends remain in sync: that's relatively easy using idempotent block writes compared with what's required to handle more complex logical updates). - bill |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
A7N8X series "incomplete RAID set" bug - my experiences and solution | Andy C | Asus Motherboards | 0 | July 19th 05 03:06 AM |
pc problems after g card upgrade + sp2 | ben reed | Homebuilt PC's | 9 | November 30th 04 01:04 AM |
IDE RAID | Ted Dawson | Asus Motherboards | 29 | September 21st 04 03:39 AM |
DAW & Windows XP RAID Tips, ProTools error -9086 | Giganews | Asus Motherboards | 0 | October 24th 03 06:45 AM |
RAID and non-RAID combination | Howard | Gigabyte Motherboards | 3 | October 4th 03 11:54 AM |