The blktrace command can also send the tracing data over the network so that it is stored on a different device.

For this, start blktrace on the host system that is going to hold the data as follows:

$ sudo blktrace -l  

And on the target device, run another instance as follows:

# blktrace -d /dev/mmcblk2 -h <host_ip>  

Also on the target, but on a different SSH connection, you can now execute the specific workload you want to trace:

# dd if=/dev/urandom of=/mnt/home/root/random-10k-file bs=1k count=10 
  conv=fsync
10+0 records in
10+0 records out
10240 bytes (10 kB) copied, 0.00585167 s, 1.7 MB/s  

Once it finishes, interrupt the blktrace on the target with Ctrl + C. A summary will be printed at both the target and the host. On the host, a new directory with the tracing data has been created with the format:

<ipaddress>-<date>-<time> 

You can now run blkparse on the host to process the gathered data by providing the directory path and the device name:

$ blkparse -D <directory-name> mmcblk2