2012-08-09 11:52 PM
last month our new FAS3270 was installed. The system is still in test stage at present, but it shall be used productively soon
The FAS3270 is fitted with a 512GB Flash Cache Card. We've got no experiencies with this card and it's performance, therefore we are testing. Under consideration of "TR-3832 Flash Cache Best Practices Guide" we created different volumes (with identical parameters - priority set volume volumename cache=keep) , declared as LUNs and CIFS-Shares. Now we began copy data from LUN to LUN, from CIFS-share to CIFS-share and so on.
With "stats show -p flexscale-access" we can see (Hit /s and Hit %) that the Flash Card is used by read access with volumes witch are created as LUNs. But it looks like the Cache is not used by read access with CIFS-Shares.
Copy data: LUN to LUN
Copy - the same - data: CIFS-Share to CIFS-Share
What's wrong ?
Thanks and kind regards
2012-08-10 06:34 AM
usualy the data needs to be cached once. means you copy the first time, no hits, you copy the second time, more hits.
your lun data could be already cached as the servers are already using the data before.
did you try reading a dataset twice?
2012-08-12 10:37 PM
Thank you, for your answer.
Yes, we 've copied the dataset (5GB - with 5.166 files of different size) more than one time. To test the performance, we copy the datasets repeatedly at different times. By using LUNs it looks fine, by CIFS-Shares - no cache access.