DataMover is an Enterprise Storage stress and data integrity test application written for Windows and Linux kernels.   DataMover is also a sophisticated I/O generator application used to measure the IOPS and maximum throughput performance of a storage subsystem.  DataMover is written in native Windows and Linux API's to maximize performance; both applications have been designed and written separately to take advantage of specific kernel attributes.  There is no porting between the applications, no JAVA and no .NET components called explicitly.

If performing synchronous I/O to logical targets, DataMover has no control over the timeout value which is set by the kernel.  If performing asynchronous I/O to logical targets, DataMover implements a two minute timer for the asynchronous procedure calls to complete.  The table below defines the I/O timeout behavior on DataMover For Linux and DataMover For Windows.

Currently, Windows and Linux.

Yes, you can create and import custom patterns of your own design.

I/O to a physical target eliminates the programming overhead associated with a file system therebye improving throughput. 

For Windows, try enabling HTTP version 1.1 for proxy authentication in Internet Explorer Advanced Options settings.  Proxy support on DataMover For Linux not currently supported.

The minimum size for logical and physical targets are dependent on the following factors:  I/O depth (if asynchronous), tread count, and buffer size.  For the performance test, the minimum logical target size is 128MB; the minimum physical target size is 1664MB.

The Moojit can provide an on-site licensing server with a minimum purchase of five client seats or the HASP USB licensing key can be used which requires no internet connectivity.

Yes, if you're performing I/O to a physical target all data has the potential of being destroyed.  Use this feature with extreme caution and in non-production environments!

This may be due to usbfs not being mounted automatically.  Type 'mount –t usbfs none /proc/bus/usb/' to mount usbfs and re-run the datamoverinstall.sh script or restart the aksusbd service by typing 'service aksusbd restart.'

Make sure the storage LUNs in Disk Manager are marked as 'Online.'  If they say 'Offline,' asynchronous I/O will not work.

The excel template available on the Downloads page as part of the data pattern files package may be used to copy and paste the raw data sets from DataMover's comma delimited files.  Before using the template, open the comma delimited file using excel.

There must be atleast one valid ethernet interface defined on the system (eth0, eth1 , ..., ethn).

The client only, XP and Vista do not support the number of inbound connections required to run the server application.

Beginning with version 2.8.3 of SCSI Utility and version 2.9.4 of DataMover For Windows, Windows 2000 and Windows 2000 Professional are no longer supported.

On Linux, DataMover uses the information provided by the block descriptor in the /sys/block/sd%/queue/max_sectors_kb file.  DataMover will use this value to determine how many transfers are required to complete the selected transfer size.  For example, if the user selected a transfer size of 1MB and the block device supports a maximum transfer size of 256KB, a total of four 256KB transfers will be required to complete the 1MB transfer.  If using a bus analyzer to monitor traffic, you would see four 256KB transfers taking place.

On Windows, DataMover uses the maximum transfer and page file size reported by the adapters driver to calculate the adapter's maximum transfer size when synchronous I/O is selected.  This value is typically 64KB.  For example, if the user selected a transfer size of 256KB and the adapter supports a maximum transfer size of 64KB, a total of four 64KB transfers will be required to complete the 256KB transfer.  For asynchronous I/O, DataMover does not calculate or control the maximum transfer size, this will be determined by the class driver.

But what happens if the transfer size selected by the user is less than the maximum transfer size supported by the adapter?  In this case, the I/O transfer size will be the value selected by the user in the GUI.  Referring back to our original 64KB maximum transfer size example, if the user selects a 2KB transfer size using a 1MB data buffer size, 512 2KB transfers will be required to fill the 1MB buffer.  If using a bus analyzer to monitor traffic, you would see 512 2KB transfers taking place.

The table below provides a number of examples for the DataMover For Windows synchronous I/O case, assuming the adapter supports a maximum transfer size of 512KB.

Yes, beginning with version 1.8, 32bit and 64bit versions of the DataMover for Networks application are interoperable.

No.

Yes.  DataMover presents all throughput data in MiB format where 1024 bytes = 1 KB, 1024 KB = 1 MB, etc. determined by a base 2 numbering system.  If you want to convert from MiB to MB (1000 KB = 1 MB), multiply by 1.05.

The load balancing policy must be set to 'Failover Only' when performing the target cluster tests.  This will maintain the I-T-L nexus in a multipathing environment.  For example, if the load balancing policy is set to 'Round Robin' the path used to send the RESERVE, IO, and RELEASE may not be the same.  This will cause false errors.