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25 Dell HPC NFS Storage Solution – High Availability (NSS7.0-HA) Configuration
IOzone Argument
Description
-I
Use O_DIRECT, bypass client cache
-O
Give results in ops/sec
For the sequential tests, file size was varied along with the number of clients such that the total amount of
data written was 512 GiB (number of clients * file size per client = 512GiB).
IOzone Sequential Writes
# /usr/sbin/iozone -i 0 -c –e –w –r 1024k –s 16g –t 32 -+n -+m ./clientlist
IOzone Sequential Reads
# /usr/sbin/iozone -i 1 -c -e -w -r 1024k -s 16g -t 32 -+n -+m ./clientlist
For the random tests, each client read or wrote a 4GiB file. The record size used for the random tests was
4KiB to simulate small random data accesses.
IOzone IOPs Random Access (Reads and Writes)
# /usr/sbin/iozone -i 2 -w -r 4k -I -O -w -+n -s 4g -t 1 -+m ./clientlist
By using -c and -e in the test, IOzone provides a more realistic view of what a typical application is doing.
The O_Direct command line parameter allows us to bypass the cache on the compute node on which
we are running the IOzone thread.