Shadow Copy question...

94jedi

I hope this is the right place for this question...

Anyway, our data storage server is running Shadow Copy (VSS) on it. Currently, I have the Shadow Copies set to go to a 750GB ext. hd. Every 3 months or so, we fill up the ext hd with Shadow copies, then one day, "poof" and they're all gone and it starts over. I have the Shadow copy settings set to use a limit of 640GB of the drive. Should I set it to "no limit"? What I'm hoping that will do is just replace the oldest snapshot with the newest snapshot each time. What I can't afford is for all my Shadow Copies to disappear every three months or so.

BTW- VSS is NOT my only layer of back up. It's actually my third but it's also the quickest and most convenient.

Thanks!

surfthegecko

Could be wrong but im sure VSS will always overwrite the oldest data first when it reaches its limit whether its a restricted limit or whether it just uses the whole drive.

dales

Yes if it reaches any limit be it size limit or max number of shadow copies it will start overwriting the oldest ones in a cycle.

Are you sure this is not coinciding with any thing else happening on that server or your network. no scheduled tasks or cleaner using the external drives socket for a bit of fluffy dusting!?

sprkymrk

There are a couple of bugs in VSS. It happens here on occasion as well, and though it has been a while since I researched it, there was no fix. Apparently spikes in I/O can cause it. It was supposed to be fixed in a service pack or patch, but it still happens here. Lots of google information on that, as well as others (like myself) that have applied the patches and still lose shadow copies.

Here is something else I found:

kb833780 wrote:

This issue may occur if you use the Shadow Copies of Shared Folders feature, and the shadow copy storage area is on a different volume than the volume that is enabled for shadow copies.

When you start your server, the volume that hosts the shadow copy storage area must be available. If this volume uses a storage interconnect type that takes more than 30 seconds to make the volume available, all shadow copies for the other volume are deleted. Storage interconnect types that may take more than 30 seconds to make a volume available include SCSI, Fiber Channel, and iSCSI.

surfthegecko

I would question whether the best storage device is in fact an external device, as its IDE/SATA connection is running via USB (or maybe Firewire) connection.

Would it make a difference if you used a hard drive connected to a motherboards built in IDE/SATA ports?

Just an idea. Maybe there is less chance of I/O spiking if its using onboard controllers.

Anybody got any thoughts on this suggestions.