I had previously commented on how to use the FPLIB facility in a trace event but the question came up today of how to trace HCC in an offload server. The facility name in this case is ADVCMP (Advanced Compression) and the hierarchy is:
No compression occurs on the cell so we are only interested in the decompression tracing in an offload server.
So in this case the correct syntax is
cellcli -e 'alter cell offloadgroupEvents = "trace[advcmp.advcmp_decomp.*] disk=lowest"'