Short Description: Compress attachments stored within the transaction logs using the LZ1 algorithm whether or not they have been stored compressed within the Domino database.
Starting at Domino 8.5 and ODS level 51, log compression is not enabled. Transaction Logging will store the data in the same format as the database. If the data is already compressed, it will be compressed in the transaction logs. If the data is not compressed, the data will not be compressed in the transaction logs. What data is being referred to here? It could be data documents, design documents or attachments.
There are some cases where, for performance reasons (most often on system z and IBM i systems), you may want to compress your transaction logs, but not compress your data.
In this case there is one NOTES.INI settings that can accomplish this for you:
NSF_ENABLE_LZ1_TXN_LOGS=1 Compress attachments stored within the transaction logs using the LZ1 algorithm whether or not they have been stored compressed within the Domino database.
NSF_ENABLE_LZ1_TXN_LOGS=0 / 1
Redbook: Optimizing Lotus Domino Administration