High write activity (physical):<number of> pages/second

There are a high number of physical writes to the data devspaces as the data requested by the applications cannot be fully stored in the data cache. In addition, data is being forced out of the cache and on to the hard disk. During large data imports, data is almost always forced out of the cache, as the imported data volume is usually much larger than the cache.

There is a savepoint at regular intervals (default: every 10 minutes). This involves a flushing of the data cache with all changed pages being written to the disk to ensure a consistent database state in the devspaces. During this process, the I/O activity increases dramatically (disk load close to 100%), without this being a true bottleneck. During normal operation, there shouldn’t be high amounts of write activity besides the savepoints.

If high amounts of write activity are noticed during normal operation, first check to determine whether this is due to a savepoint that may have occurred during the check interval (which may also have been too short). Otherwise, only by increasing the size of the data cache can the cache displacement be avoided.