Vtrak not synchronizing between 2 computers

[user980673]

We have a a Vtrak 12110 hooked up via SCSI cable to 2 Dell servers running Windows Server 2003. They're hooked up exactly as show on page 19 of the Vtrak User manual (Link) It's called "Configuration 3: One VTrak, two Host PCs, one SCSI HBA card in each". We also have 2 RAID-5 arrays built showing as 2 logical drives. Now here's the problem. The drives are able to be seen and accessed from either Dell Server. The problem comes in when we write a file to either one of the arrays, it looks like it wrote fine (disk activity lights flash, file is able to be read back from the array) but when we go to the other server, the file is not there.

Example:
[ul]
[li]Write testa.txt from Server A to array[/li]
[li]testa.txt cannot be seen from Server B[/li]
[li]Write testb.txt from Server B to array[/li]
[li]testb.txt cannot be seen from Server A[/li]
[/ul]

Most troubling example:
[ul]
[li]Write test.txt from Server A to array[/li]
[li]File saves fine[/li]
[li]Write test.txt from Server B to array[/li]
[li]Can't see the test.txt I made from Server A[/li]
[li]File saves fine!?[/li]
[/ul]

The biggest problem is the fact that it is letting me create a file thats exactly the same name on the same drive as if the other file never existed.It's as if each server has it's own independent copy of the array even though it's the same physical device.

Any suggestions would be appreciated.

 

[chgwhat]

Block devices can only be used by one computer at a time, unless you are using a cluster filesystem, which ntfs is not.

Tony ... aka chgwhat

When in doubt,,, Power out...

 

[user980673]

Thanks for the reply. So what's the best way to use the Vtrak with both my Server2K3 boxes simultaneously with no conflicts? Reformat it using a cluster filesystem?

 

[chgwhat]

I think you have a few options in no particular order.

- Reformat to 2 LUNs, and assign their SCSI id to only one host. Each server will see just one lun, and no data will be shared. Unless you share over the network.
- Install windows cluster and allow one one server access to the LUNs. If this is supported? The other server would be a hot standby.
- Assign the LUNs to one server, and network share to the other. The other could be a poorly designed cold standby server, with a 3 day recovery if the first server died.
- The complexities of cluster filesystems and the hardware and software they support may mean the best option is buy a NAS.



Tony ... aka chgwhat

When in doubt,,, Power out...