In order to have our '''Koji ''' Build Farm run as efficiently as possible we needed to find out which form of data storage would be the fastest overall. The candidates were: * '''PATA:''' Hard Drive connected via USB.* '''NFS:''' Share from HongKong.* '''iSCSI:''' Network connection to HongKong. ===What results are we interested in?=== There are 3 main results that we are interested in when rating storage performance.

* PATA Hard Drive connected via USB'''Read:''' The amount of data that can be read from the storage medium per second.* NFS share from HongKong'''Write:''' The amount of data that can be written to the storage medium per second.* iSCSI network connection '''Access:''' Time required for a computer to HongKongprocess data from the processor and then retrieve the required data from a storage medium.

1Since '''NFS''' and '''iSCSI''' are both network storage solutions they have no cost in themselves, but rely on network storage on a remote server. Read: The amount This price is simply the cost of data that can be read from the storage medium per second.<br>2. Write: The amount of data drives that can will be written to installed in the remote storage medium per secondserver.<br>3. Access: Time required for A USB connected PATA or SATA drive requires both a computer to process data from the processor hard drive and then retrieve the required data from a storage medium'''PATA/SATA''' to '''USB''' interface such as an external drive enclosure.

Another factor is cost. Since * '''NFS and :''' Free (Uses existing storage)* '''iSCSI are both network :''' Free (Uses existing storage solutions they have no cost in themselves, but rely on network storage on a remote server. This price is simply the cost of the drives that will be installed in the remote storage server. A )* '''USB connected PATA or SATA drive requires both a hard drive and a PATA/SATA to USB interface such as an external drive enclosure.:''' ~$100 CAD

http://david-chisholm.no-ip.org/bonnie.jpg<br>http://www.paladinretrieval.net/hard%20drivenetworkdiagram.jpg

*Benchmark using a linux untiliy called '''Bonnie++''' written by Russell Coker.*The Benchmark was run 3 times on each medium, the results were then averaged together. *The command used is as follows:

The process ===What was simple, find a storage solution that would result in the best build times while using the most efficient use of the storage resources available process we used to us.choose our benchmarking solution?===

The main issue encountered goal was finding to find a repeatable benchmarking storage solution what that would give result in the desired results best build times while being able to test all 3 using the most efficient use of our the storage mediums. Common Linux tools such as the DD and HDPARM commands are capable of doing disk benchmarking, but will only work for physical devices and not network networked ones, making them useless tests for our purposesresources available to us.

The main issue encountered was finding a repeatable benchmarking solution what would give the desired results while being able to test all 3 of our storage mediums. Common Linux tools such as the '''DD''' and '''HDPARM''' commands are capable of doing disk benchmarking, but will only work for physical devices and not network networked ones, making them useless tests for our purposes. The solution was '''Bonnie++''', a Linux command line utility which gives an extensive amount amount of storage performance information while also having the ability to test all of our storage systems. ===Pictures=== http://www.business-strategy-innovation.com/uploaded_images/Innovation-Process-799858.jpg

===What did we discover during the process?=== We discovered that finding a viable benchmarking solution is harder then it sounds. Raw data will not always correspond with real results as it comes down to the application using those resources. This is evident in the mock tests using '''NFS ''' vs '''USB PATA ''' where '''USB PATA ''' performed faster even though its benchmark results were lower using '''Bonnie++'''. ===Pictures=== http://thumbs.dreamstime.com/thumb_122/1171633495w0G6A0.jpg

===USB PATA works ===*Works without issue. NFS works, but results in longer build times than USB PATA even though it benchmarked at higher speeds.

iSCSI seems to work===NFS===*Works, but only to a pointresults in longer build times than USB PATA even though it benchmarked at higher speeds.

===iSCSI===*Seems to work at first, but only to a point.*We can login to an initiator, however, under heavy load the target receives invalid opcodes, causing the connection to fail.*Experimenting with a /proc/cpu/alignment value of 3 (fixup+warn) did not clear the issue.*Using the exact same target with a F12 x86_64 initiator is successful, issue seems to be '''ARM''' related.