Doubt about how to create a Calculated Item

[furlanetti]

Hello everyone

I need some help to create a Calculated Item please.

I'm trying to calculate two items and sum the last values collected.

These items are the IO Read/Write of the all volumes from a Failover Custer CSV Volumes:

- IO Write Bytes/sec - TOTAL perf_counter["\\{HOST.HOST}\Cluster CSV File System(*)\IO Write Bytes/sec"]
- IO Read Bytes/sec - TOTAL perf_counter["\\{HOST.HOST}\Cluster CSV File System(*)\IO Read Bytes/sec"]

But I don't know what I'm doing wrong, because I'm receiving this kind of messages:

- Incorrect function 'last' expression. Check expression part starting from:

I'm using this expression to sum the values:

- last("perf_counter["\\{HOST.HOST}\Cluster CSV File System(*)\IO Read Bytes/sec""])+last("perf_counter["\\{HOST.HOST}\Cluster CSV File System(*)\IO Write Bytes/sec""])

Thanks