MDL Reads/sec is the frequency of reads from the file system cache that use a Memory Descriptor List (MDL) to access the ...

MDL Reads/sec is the frequency of reads from the file system cache that use a Memory Descriptor List (MDL) to access the data.  The MDL contains the physical address of each page involved in the transfer, and thus can employ a hardware Direct Memory Access (DMA) device to effect the copy.  The LAN Server uses this method for large transfers out of the server.