Rahul Nabar wrote:
I now ran bonnie++ but have trouble figuring out if my perf. stats are
up to the mark or not. My original plan was to only estimate the IOPS
capabilities of my existing storage setup. But then again I am quite
Best way to get IOPs data in a "standard" manner is to run the type of
test that generates 8k random reads.
I'd suggest not using bonnie++. It is, honestly, not that good for HPC
IO performance measurement. I have lots of caveats on it, having used
it for a while as a test, while looking ever more deeply at it.
I've found fio (http://freshmeat.net/projects/fio/) to be an excellent
testing tool for disk systems. To use it, compile it (requires libaio),
and then run it as
fio input.fio
For a nice simple IOP test, try this:
[random]
rw=randread
size=4g
directory=/data
iodepth=32
blocksize=8k
numjobs=16
nrfiles=1
group_reporting
ioengine=sync
loops=1
This file will do 4GB of IO into a directory named /data, using an IO
depth of 32, a block size of 8k (the IOP measurement standard) with
random reads as the major operation, using standard unix IO. We have 16
simultaneous jobs doing IO, each job using 1 file. It will aggregate
all the information from each job and report it, and it will run once.
We use this to model bonnie++ and other types of workloads. It provides
a great deal of useful information.
ignorant about the finer nuances. Hence I thought maybe I should post
the stats. here and if anyone has comments I'd very much appreciate
hearing them. In any case, maybe my stats help someone else sometime!
I/O stats on live HPC systems seem hard to find.
It looks like channel bonding isn't helping you much. Is your server
channel bonded? Clients? Both?
Data posted below. Since this is an NFS store I ran bonnie++ from both
a NFS client compute node and the server. (head node)
Server side bonnie++
http://dl.getdropbox.com/u/118481/io_benchmarks/bonnie_op.html
Client side bonnie++
http://dl.getdropbox.com/u/118481/io_benchmarks/bonnie_op_node25.html
Caveat: The cluster was in production so there is a chance of
externalities affecting my data. (am trying it hard to explain why
some stats seem better on the client run than the server run)
Subsidary Goal: This setup had 23 clients for NFS. In a new cluster
that I am setting up we want to scale this up about 250 clients. Hence
want to estimate what sort of performance I'll be looking for in the
Storage. (I've found most conversations with vendors pretty
non-productive with them weaving vague terms and staying as far away
from quantitative estimates as is possible.)
Heh ... depends on the vendor. We are pretty open and free with our
numbers (to our current/prospective customers), and our test cases.
Shortly we are releasing the io-bm code for people to test single and
parallel IO, and publishing our results as we obtain them.
(Other specs: Gigabit ethernet. RAID5 array of 5 total SAS 10k RPM
disks. Total storage ~ 1.5 Terabyte; both server and client have 16GB
RAM; Dell 6248 switches. Port bonding on client servers)
What RAID adapter and drives? I am assuming some sort of Dell unit.
What is the connection from the server to the network ... single gigabit
(ala Rocks clusters), or 10 GbE, or channel bonded gigabit?
--
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Founder and CEO
Scalable Informatics, Inc.
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