Quote Originally Posted by Computurd View Post
is there any way to monitor then give us a readout of the file sizes used, at the physical device level only, like say a percentage of each file size used during normal desktop
like a percetage of 4k 8k 16k 64k etc etc???
Quote Originally Posted by johnw View Post
+1

I was about to ask the same thing. If hIOmon cannot produce a histogram, at least a tabular list or Excel file with breakdowns of physical device I/O frequencies for each block size (number of contiguous LBAs read or written)
Hi CT,

I/O operations performed at the physical device level within the OS I/O stack are fairly ignorant of the associated file (if any) and respective file size.

For instance, take a single physical device read I/O operation that has a data transfer length of 4096 bytes (i.e., eight 512-byte sectors). This physical device level read I/O operation could be the result of a read I/O operation for a file whose length ("file size") is one byte, or 511 bytes, or 4096 bytes, or 1MB, etc. - you get the story.

Moreover, the file could be 10MB in size, but the application only accesses (perhaps repeatedly) the first 64 KiB.

Anyway, I suspect that you are interested in capturing a breakdown of the "data transfer length" frequencies (as johnw subsequently mentioned) for I/O operations down at the physical device level within the OS I/O stack.

This is something that the hIOmon software can also handle. I won't go into all of the details here, but one approach is to have the hIOmon software collect an "I/O operation trace" of physical device I/O operations, from which a hIOmon "Transfer Size Summary (TSS)" export file can be generated.

This hIOmon TSS export file is a CSV-file that can include a variety of metrics pertaining to each distinct "data transfer length" observed.

I anticipate that Ao1 with have some empirical data along these lines soon.