jeff> We're using Legato and NDMP to backup our filers. While we jeff> aren't on 7G yet, we do have a couple of "large, large, large" jeff> data volumes.
Can you define large? I've got a 3.5Tb volume we have to backup, and it takes forever.
We have several large file systems based on size and/or file count. One vol is 3.5 TB with 9.5 MM files, one is 1TB with 7.4 MM files, one is 2.6 TB with 5.9 MM files. We have a few other volumes as well, but don't consider them to be "large". Fulls take about 36 hours on that 3.5TB guy (only volume on that filer). Fulls on the other volumes take about 18 hours (other volumes both on 2nd filer). We do three-way backups to the Overland library which is FC-attached to one host.
jeff> To work around the DAR limitation of 1 MM files, we use the jeff> qtree method you propose below. All data is stored in qtrees jeff> and each qtree is listed individually on the client in Legato. jeff> It creates a little more management overhead in that we have to jeff> be sure that all new top-level directories are added as qtrees jeff> (we've had a few sneak in that weren't) and add them to Legato, jeff> but it works well for us.
I think this is the step we're going to take. We really want the flexibilty of FlexVols in 7G, along with lots of qtrees, we should be ok.
jeff> We're looking forward to Legato 7.2 to allow us to do multiple jeff> NDMP streams to a single tape device. Our filers backup to an jeff> Overland Neo 4100 with 4 x LTO-2 drives and we can't push the jeff> drives as fast as we'd like to.
We've just upgraded all our sites to Legato Networker 7.2, now we need to do some upgrades to 7G and start testing out NDMP backups and see how well they work out.
We have a small number of SuperDLT drives at each site, so not being able to Multiplex multiple NDMP data streams to a single tape drive was a really problem for us. Hopefully we won't run into too many problems with this in Networker 7.2.
Are any people out there planning on setting up filedevices for their NDMP backups, and then cloning them to tape? That seems like a good way to do it, esp if you have a big enough disk farm. It might only work well for incrementals though, not for Fulls.
File devices are an intersting idea. Unfortunately we don't currently have the space to do that. We are investigating disk-to-disk and virtual tape backups which may offer up some alternatives, but we're not far enough along there to provide useful comments.
Jeff Mery - MCSE, MCP National Instruments
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