Parsing captured data

Run the created data through blkparse.

# blkparse -D 9.152.37.153-2007-10-31-11\:38\:40/ sda -d events.bin \
> events.txt

blkparse creates a text file with the I/O events and a summary. It optionally also creates a binary file for later processing with btt.

If only read requests or only write requests should be analyzed by blkparse or later by btt, -a read or -a write can be added to the blkparse command line. The end of the text log file shows as part of a summary the number of read and write requests and the total amount of read and written data. The same text file also lists all events related to I/O requests that have been captured by blktrace. The summary at the end looks like this:

Total (sda):
Reads Queued:         60,      240KiB Writes Queued:       1,257K,          5,030MiB
Read Dispatches:      60,      240KiB Write Dispatches:   15,153,           5,030MiB
Reads Requeued:        0       Writes Requeued:              75
Reads Completed:      60,      240KiB Writes Completed:   15,078,           5,030MiB
Read Merges:       0, 0KiB     Write Merges:               1,242K,          4,970MiB
IO unplugs:         1,193      Timer unplugs:               859

Throughput (R/W): 2KiB/s / 46,340KiB/s