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Does anyone know what the maximum number of hard drives can be spanned together as a single drive letter (not NTFS mounted in a folder, and not hardware raid)
For example,
if you had 6x2TB hard drives = 12TB, can you span that together into a single drive letter, or is there a ceiling that gets hit at some point? Other than physical limitations of the case/mobo.
It would be in an x64 system (vista or more likely Win7) so there shouldn't be any 32 bit boundry to deal with.
What like DFS?
I guess you could say "like DFS", but it wouldn't be a viable solution since this would be a single client workstation, no servers.
Windows supports spanned disks, I just want to find out what its max capacity is for doing this in terms of
1) number of physical drives it would support
2) maximum individual drive size it would support
3) maximum total spanned drive size it would support
there "was" a 3 terabyte limit, but i believe sp1 removed it. As for "32-bit boundary", this doesn't apply to hard drives formatted in ntfs 5 or higher, no matter what OS they are on. It uses a 64-bit index, with a standard logical sector of 2048 bytes (physical ones are 512).
There are possible software issues for root drives, but vista and 7 are not affected. xp sp1 and below can't be installed on a disk above a certain size but annoyingly can access bigger drives.
This would not be the OS drive, basically the setup would be
1xSSD or 1xvelociraptor as OS "C" drive
6x2TB as spanned "D" drive
I knew there was no 32 bit boundary in actual disk size, but i didn't know if there was one in terms of spanning them together at the OS level. Sometimes those weird "gotchas" creep up after the fact, so this sort of needs to be planned out accurately before hand.
XP won't even be considered as an OS for this machine. Likely it will be 7 RC then 7RTM
According to this website, the maximum size of a volume/partition on NTFS is 18,446,744,073,709,551,616 bytes (16 Exbibyte).
It doesn't cite a source, though
Edit: Wikipedia says the same.
From what I've read, spanning doesn't change this limit, but I haven't found any 'proof' of this.
when you span drives, you are basically formatting them as one drive. This gives you one single ntfs file table, therefore it would have the limit of one drive.
Have you considered spanning them with hardware? The only OS raid i've ever seen worth a crap is server's raid.
I am basically looking for a JBOD setup.
my motherboard can do that. Perhaps yours supports it as well. Although frankly if you are going jbod, there isn't any reason to not raid them 0. You would have the same chance of data loss with 6x the read/write speed.
Personally though considering how recently the drives were released, i would wait a month or so for the inevidable RMEs and random firmware problems. Hard drives are not something you should be an early adopter on.
If i had the money for the 6 drive setup you are talking about, i would get a controller card (i would have to since my mb only supports 5 sata drives unless i hook one to the external esata port) that supports raid-5 and give up 2 tb for guaranteed data redundancy. As a victim of failure, i am a proponent of redundancy. However, if your board does support that many drives, you may be able to use server 2008 to set up a software raid-5 and windows 7 should still be able to access it.
Raid 0 would require all the same disks no? The 6x2TB was just theoretical. The system isn't built yet (or parts ordered). It isn't even for me, it is for someone else for a project we are doing. We could possibly end up with a set of drives of mixed sizes, or even if it is 6x2TB, we may want to cycle out 2TB drives in favor of larger ones once they are available and economical. Fast read/write speed is not critical as the drives will just be media storage. I have a similar setup, but I run Windows Home Server on mine (which does JBOD via software) and speeds are acceptable there.
Also for this particular setup we are looking to build, redundacy isn't a concern for this project, we will actually eventually have 2 of them in separate locations, so the system will be mirrored offsite.
raid 0 doesn't require all the same disks. That was only a requirement with early chipsets. Nowadays they don't even have to be the same size, but each drive will be treated as if it is the size of the smallest one. Software raid never had the requirement. I am not sure about hardware, but with software raid-5 you should be able to replace one drive at a time with a larger drive, and rebuild the array after each replacement. After all drives are replaced you could resize the partition to take advantage of the larger sizes.Quote:
Originally Posted by kleinma
But isn't this something that software based disk spanning would do automatically? Or do you think the built in disk spanning features in Windows Client lack the ability to migrate a drive out and migrate another drive in without manual data recovery?
Also yeah that is what I mean by "same size", that you can't really get a good mixed size drive array because there will be wasted space.
Windows Home Server and its drive extender service actually do this perfectly, but I don't think WHS will be a solution here because it can not really be used as a client OS.
yes it would rebuild automatically, but it's not an instant process. raid-5 uses a checksum method based on the content of every other drive, so if there's rebuilding to do, it has to reconstitute the new drive based on the contents of every single other drive. This is time consuming. Personally, i used raid10 when i had it setup, but i didn't have the space requirements.
And vista ultimate can read raid-5 created in server 2003, so i would assume windows 7 could also.
There won't be any server though. Basically what we need to build is a client PC with a TON of storage.
would you please state your reason for eliminating windows home server? It can be used as a clent OS and is vista-compatible.
It is not a client OS. Not at all. It runs on top of 2003 server.
It's based on 2003 server, sharing most of the code base. This is according to Microsoft. This makes it functionally identical to xp, i guess. If he needs vista functionality, he would need server 2008 (directx 10 for example). It would need major tweaking to cut out some admin annoyances such as the "enter a reason for shutdown"Quote:
Originally Posted by kleinma
yeah it just is not a viable solution to be a client OS, nor is it supported. Hooking a monitor up to it is not even officially supported. It is supposed to run as a headless system.
Also you ONLY get 20 GB for the OS (C) drive and there is no way to change this. Everything else has to be written through the drive extender service to the "virual" shares.
well that was useful information i was not aware of. Kind of making me rethink trying it myself. I really like the automatic system backups and drive rebuilding. The "shares" do not seem to be any different than a standard winshare though.Quote:
Originally Posted by kleinma
Personally, having crammed six drives in a system, i can say if i had the money and had to do it over again, i would get a drobo. http://www.drobo.com/resources/drobodemo.php
I really can't help any better than that.
yeah believe me it really is hard to find the solution that does EVERYTHING you want it to do.
The reason WHS is really good is:
-pools all drives of any sizes together into 1 large file share that is further divided up via folders
-does full backups of other PCs on the network to restore later in the event of system failure or corruption
-has folder level redundancy capabilities, not drive level
-remote access to upload/download (limited to uploading 2GB file sizes)
-"some" direct media streaming capabilities
the reasons it is bad is when you want to actually have a functional computer. WHS is really a "tuck away in the closet, only remote to it when needed" sort of device.
However its storage capabilities are far beyond those drobo systems.