So I was getting ready to grow FAST Cache on a VNXe3200. First thing I found was that the EMC support site search is terrible. Not that I didn’t know that already, but just had that re-emphasized. Search for “How to expand FAST Cache on VNXe3200” and you will get a whole bunch of old unrelated documents. Once I found a few somewhat related guides, it said to delete the existing FAST Cache (FC) and then recreate it using the new drives. There is a warning in a different guide that says you should wait until all existing dirty pages are cleared from FC before deleting and a sample command for VNX naviseccli is given. Since this is a VNXe I was looking for the uemcli command and couldn’t find the example. There are a number of examples for other config items for uemcli, but I couldn’t find a FC Dirty Pages reference so here is what I did.
Thankfully the lab at work has a VNXe3200 in it. After some googling and a couple minutes in the lab, here is what I came up with. Should get the info you need and hopefully save you a few minutes of messing around with Google and admin guides.
uemcli -d SP.IP.Add.ress -u Local/admin -p YourP@Ssword /metrics/value/rt -path sp.*.blockCache.global.summary.dirtyPages show -interval 5
Replace the SP.IP.Add.ress with your Storage Processor IP Address or DNS name and YourP@Ssword with your admin password and you should get something that looks like this. The very helpful guide for growing FC on VNX and Clarion says this:
Solution: How to expand or shrink the FAST Cache in CLARiiON CX4 and VNX
There were some article links, one of which is how to flush or destroy FC. Not sure if that is a public document, so here are the pertinent parts.
How to flush and disable FAST Cache
Why FAST Cache can take a very long time to flush when it is disabled for the whole array
FAST Cache can take a very long time to flush.
FAST Cache will flush very slowly if it is disabled/destroyed at a global level in FLARE prior to 04.30.000.5.512.
FAST Cache may stick at zero percent cache dirty when it is disabled/destroyed.