How do I determine the disk I/O speed of a node in the Junos Space fabric?
You can determine the disk I/O speed of a node in the Junos Space fabric by logging in to the node as an admin user and executing the following command:
dd if=/dev/zero of=./test bs=8k count=500000
where test is the name of the file to which the command output is copied.
The following is the command output:
500000+0 records in500000+0 records out4096000000 bytes (4.1 GB) copied, 15.944 seconds, 257 MB/s
where 257 MB/s indicates the I/O speed of the disk.
We recommend that you delete the test file after determining the I/O speed.
Note: The minimum disk I/O speed recommended for Junos Space Virtual Appliance is 200 Mbps.
For more information about Junos Space Appliances and Junos Space Virtual Appliances, click Junos Space and Applications.
Thanks for the great information about the dd command, one note though; you mentioned the minimum disk I/O speed recommended for Junos Space Virtual Appliance is 200 Mbps; that is bits per second which is equal to (200 Mbps / 8 bits) = 25 MBps, is this intended or did you mean the minimum is 200 MBps?
Also is the theme for Junos Space disk access sequential or random, as this reflect the bandwidth needed?