I see two possible issues. Most likely, your issue is caused by using hard disks that are Advanced Format drives. AF drives are not inherently compatible with the X310 because it is running the original version of Windows Home Server. That version was built ontop of Windows Server 2003. Some drives have jumper settings to adapt AF drives to work on XP, Server 2003 and WHS systems. I'd look into that. Also, it could be your Symantec product. To check, try temporarily disabling it on your connected workstations and see if slow downs go away.
I'm helping troubleshoot a network problem at a small business that's using an HP Data Vault X310. The complaint is that accessing files shared from the WHS sometimes results in a the local workstation hanging for up to 30 seconds (and possibly more, hang time is not consistent). This does not happen all of the time and cannot be duplicated on demand. When it does happen the user is always trying to access a file share, either by opening a file/folder or by trying to save a file.
We tried to duplicate the problem by having four users click constantly on folder shares, including opening some large files. We could not reproduce the problem.
The users say it can and does happen at any time during the day (not at any one specific time). It happens multiple times throughout each workday.
They have about 8 workstations accessing the WHS, but there's only about 3 of those workstations that are used very heavily.
They are using Norton Internet Security 2011/2012 for their security software on the workstations (no apparent problems). Gigabit connections all the way around going to 8-port D-Link gigabit switches.
We're still trying to figure out if this could be a WHS issue or not. Any ideas where to look?