iSCSI & Windows 7

[Mac Dude]

Hi All,

I hope this is the right spot for this

I have 3 PCs with Windows 7, and all access an iSCSI drive on our home NAS. While having 3 initiators pointing to the one target isn't recommended as it's not designed for multi-user access, it worked fine.

Recently something changed, and the only thing I can think of is a patch of some description.

Now, if I put a file on the iSCSI drive from one PC, it cannot be seen by the others unless they disconnect and reconnect. This was not the case a month ago. What's even strange:

* I drop a file on the iSCSI drive from "PC A"
* disconnect & reconnect the iSCSI drive from "PC B", I can then see the file
* I delete the file from "PC B"
* I can still see, and access the file from "PC A" even if I disconnect and reconnect
* "PC B" shows no file even if I disconnect & reconnect

I'm at a loss as to how this can be given that all PCs are pointing to the one target...

 

[Qdos]

Clearly, if all three PC's behaviours are affected, then you're either looking at recent updates they all received (or software you've added to all three) or, more likely still, something has been changed at router/switch level which is inhibiting the NAS's proper functionality.

Without more information it's impossible to say what.

 

[Mac Dude]

Clearly, if all three PC's behaviours are affected, then you're either looking at recent updates they all received (or software you've added to all three) or, more likely still, something has been changed at router/switch level which is inhibiting the NAS's proper functionality.

Without more information it's impossible to say what.

Good point!

All 3 PCs run Win 7 (Ultimate), all three receive OS updates as soon as they are available. 2 of the PCs have recently had SSDs installed, but no additional software aside from the SSD drivers. I'm fairly sure the changes to iSCSI behaviour didn't happen at exactly the same time as the SSD drive install, but I'm not 100% sure.

No software/firmware/hardware/configuration changes have been made to the NAS or network (switch & router).

I'm not an iSCSI expert, but I'm hoping I might find one here

 

[Qdos]

The SCSi issue is neither here nor there in some senses, what I suspect this may boil down to is Windows Update installing a generic driver which it shouldn't have for your ethernet adapters - which in turn is affecting NAS functionality.

If you are positive the NAS doesn't get automated firmware updates, as per what you are suggesting regards the switch/router hardware, then all it can be is something in respects of what I suggest above - or a faulty NAS operating system.

Have you tried to reboot the NAS? Can you check any logs for firmware updates if it has possibly updated itself?

 

[Mac Dude]

I just checked the iSCSI driver on all the systems and they are all the same :

NAS iSCSI-VDISK SCSI Disk Drive
Driver Provider : Microsoft
Driver Date : 21/06/2006
Version : 6.1.7600.16385

So it looks like the disk driver hasn't changed. Regarding the network adaptor, the drivers are from the manufacturers (different on each PC), but none have changed in the past month.

The NAS does not support automatic software/firmware updates, so I can guarantee nothing has changed there...

Thanks for your suggestions Qdos, I didn't think of the network drivers and I'll have a closer look at those.

 

[Qdos]

Just another thought. If you are not using Homegroup and are relying on standard networking (or even simply NAS sync'ing) then you could disable TCP/IPv6 on each network adapter in case this is clouding any issues.

That protocol is new in W7 and only Homegroup depends upon it right now.

Sorry I haven't been of any further positive help

 

[logicearth]

That protocol is new in W7...

Uhhh, no its not new in Windows 7. It was brought into Windows XP as a core networking technology back in SP1 (back in 2002). In Windows Vista IPv6 was enabled by default. Windows 7 uses the same core networking stack as Windows Vista.

 

[Qdos]

Perhaps. But it is what runs Homegroup in W7 (nothing else as far as I'm aware, and having disabled it on my network everything works as it should) and has very possibly caused adapter issues for a great many people.

In this case it's just eliminating a possible factor in the OP's issue, and is not necessarily to blame.

 

[pparks1]

I have 3 PCs with Windows 7, and all access an iSCSI drive on our home NAS. While having 3 initiators pointing to the one target isn't recommended as it's not designed for multi-user access, it worked fine.

I think this is the crux of the problem. From a server perspective and such, you cannot have multiple devices pointing to the same LUN without either a file system that can handle concurrent connections (VMWare VFS) or clustering software which can control the disk access and ensure that 1 node has access at one time (microsoft clustering services).

Remember, iSCSI is meant to encapsulate SCSI commands over ethernet and present itself as a local drive to the host computer. Without something controlling that access...that's like having the same hard drive connected to 2 machines at the same time.

You really should be using something like CIFS to share out this to the network.

 

[jrc3]

do you have mpio enabled?