DataKeeper for Windows All Documentation - SIOS

Measuring Rate of Change• Reduce the amount of data being replicated• Increase your network capacityIf the network capacity is not sufficient to keep up with the rate of change that occurs on your disks,DataKeeper mirrors will remain in a resynchronizing state for considerable periods of time. Duringresynchronization, data on the target volume is not guaranteed to be consistent.Measuring Rate of ChangeUse Performance Monitor (perfmon) to measure the rate of change that occurs on your volumes that are to bereplicated. The best way to do this is to create a log of disk write activity for some period of time (one day, forinstance) to determine what the peak disk write periods are.To track disk write activity,• use perfmon to create a user-defined data collector set on Windows 2008 or a performance counter logon Windows 2003.• add the counter "Disk Write Bytes/sec" for each volume - the volume counters can be found in thelogical disks group.• start the log and let it run for the predetermined amount of time, then stop and open the log.An alternative to creating a log of disk writes is to use perfmon to track disk write bytes/sec interactively, inthe Performance Monitor tool, and to observe the maximum and average values there.SteelEye DataKeeper handles short bursts of write activity by adding that data to its async queue. However,make sure that over any extended period of time, the disk write activity for all replicated volumes combinedremains, on average, below the amount of change that DataKeeper and your network can transmit.SteelEye DataKeeper can handle the following average rates of change, approximately:Network BandwidthRate of Change1.5 Mbps (T1) 182,000 Bytes/sec (1.45 Mbps)10 Mbps 1,175,000 Bytes/sec (9.4 Mbps)45 Mbps (T3) 5,250,000 Bytes/sec (41.75 Mbps)100 Mbps 12,000,000 Bytes/sec (96 Mbps)1000 Mbps (Gigabit) 65,000,000 Bytes/sec (520 Mbps)Network Adapter SettingsDataKeeper requires that "File and Printer Sharing for Microsoft Networks" be enabled on the networkinterfaces to make a NAMED PIPE connection and be able to run DataKeeper’s command line tool(EMCMD).To test if you can make a Named Pipe connection, try to map a network drive on the TARGET system. If thatfails, you have a Named Pipe issue.DataKeeper for Windows Technical DocumentationPage 27