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Mounting Virtual Drives as Physical Drives in Windows?
Bombcar asks: "Samba 3.0 is an excellent CIFS server, but there are some limitations. For one, you can get a networked mapped drive, but some programs (Oracle, Exchange) refuse to run on a mapped drive, but only on local drives. I know there are some closed source (read: expensive) drivers that allow a SMB share to appear to be a physical disk. Is there any equivalent in the OSS community? What I want to be able to do is mount a share from a Linux server under Windows 2000 and have it appear as if it were a local disk. This will allow many programs that refuse (for what ever reason) to use anything but physical drives to access the network." Might such software be seen as a 'circumvention device' as specified by the DMCA? The submittor mentions that there are companies in this market already, but that doesn't mean that it will remain safe.
One reason that those server programs refuse to run from network drives is locking. Last I read there wasn't near as fine grained locking available from a network drive as from a local disk. Plus the performance seems like it would just be awful. Can you imagine how long a query would take on a 1 gig table that had to do a table scan? Yuck.
In Republican America phones tap you.
What you're asking for is a SAN.
I just installed a Network Appliance FAS250 in my server room. It speaks CIFS, NFS, and iSCSI.
By the way, you're wrong... Oracle will run perfectly using CIFS shares (I'm running it now, and have been for the past few months), and NetApp has plenty of documents in their tech library showing all the different ways to use attached storage with Oracle and many other pieces of software.
With respect to speed, it really depends on the network infrastructure. I've got a Cisco GigE switch attaching 6 machines directly to a GigE port on the NetApp Filer. It is literally twice as fast than the directly attached RAID 5 (caching, etc.) arrays that it replaced.
I think that Microsoft Exchange can be installed to a CIFS share, but if not, you should look at iSCSI. My company uses Lotus Notes 4.6.7 (sweet, merciful Christ, please put me out of my misery), and it works great from a CIFS share on the NetApp.
Microsoft has a free iSCSI Initiator for Windows that will mount an iSCSI device just like any other SCSI drive in Windows. You can find several iSCSI targets for linux here.
I have about 50 Mac's on our network (graphics department) that needed to talk with the new filer. Instead of installing a klugy piece of software to make the OS9 Macs talk to the SAN at $150/seat, I installed a linux box using samba to talk to the SAN through CIFS and netatalk (AppleTalk for linux) to re-share out the samba mounts. Becides some quirks (Mac's don't see the linux gateway in the AFP browse list, but can connect directly through IP), it works rather well.
Look at iSCSI, it does exactly what you're looking for.
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There is an excellent command-line GNU tool out there called FileDisk, by Bo Branten.
FileDisk is "a virtual disk driver for Windows NT/2000/XP that uses one or more files to emulate physical disks." ("files", meaning disk images)
His homepage at http://www.acc.umu.se/~bosse/ seems to be down at the moment, or maybe I'm just DOS'ing myself.
I'm sure you can find it somewhere out on the 'net, I did only a week ago.
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What you are after is iSCSI. iSCSI standards for Internet SCSI and is a "method of encapsulating SCSI over TCP/IP". iSCSI allows a network share to appear as a local scsi drive to the operating system. So you need a server that supports the iSCSI protocol and a client that support it also.
This site seems to be quite informative on the status of the various Linux projects. Check this out for a server implementation
The Romans didn't find algebra very challenging, because X was always 10