SnapMirror will consume as much bandwidth as it can get. I have a DS3 between Minneapolis and Denver and SnapMirror will flood it 100% no matter if it's a full or incremental transfer. The only difference is how long it floods the pipe.
There's two areas where you can change this. If you can set QOS on your VPN link between Filers IP addresses and set a reasonable bandwidth parameter, I would do that. Otherwise you can set in in Filerview when setting up the Snapmirror volume relationship under Maximum Transfer Rate. This can be tedious as you have to set it on each replicated volume. We set it on our Cisco router to run at 10 Mbit during the day and automatically jump to 40 Mbit after 10:00 PM.
I replicate Exchange and SQL data daily with logs getting replicated every 2 hours. My delta changes are roughly 300 gigs per night and at 40 Mbits (the other 5 Mbits we reserve for AD replication and normal network traffic), it takes about 6 hours. SnapMirror also doesn't thread its transfers. It just blasts the pipe so if you can stagger your transfers you should get better throughput.
Good luck, John
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Lori Barfield Sent: Thursday, November 10, 2005 10:50 AM To: toasters@mathworks.com Subject: snapmirroring over WAN
for offsite backups, we hope to snapmirror our new fas 3020 on a regular schedule via vpn over the internet to an older filer at our colo. obviously, intermittent latency is a concern since we don't have a dedicated link. and so is the potential for overpowering the modest firewall/network hardware currently in place. does anyone have a suggestion for how we might throttle the snapmirrors to improve reliability in the transmission?
and how are you folks handling encryption for remote mirroring? we have a small pix, sonicwall, or cisco to choose from...i'm guessing we may have to try all three but i hope to pick the one most likely to succeed the first time.
...lori