On Wed, Mar 27, 2013 at 3:08 PM, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> wrote: > On 3/27/2013 4:06 PM, Mark Knecht wrote: > >> All that said, I still don't really know if I was starting over today >> how to choose a new chunk size. That still eludes me. I've sort of >> decided that's one of those things that make you guys pros and me just >> a user. :-) > > Chunk size is mostly dictated by your workload IO patterns, and the > number and latency of your spindles. Is there a way for me to measure, say over a whole day or some fixed time, what the workload really looks like? The machine is a basic Gentoo desktop machine running KDE. The only workload where I really care about performance is that I run a bunch of Virtualbox Win 7 & Win XP VMs where I need to the performance to be as good as I can reasonably get. The problem I have is these VMs are either 1 huge file (40-50GB in a single file) or many 2GB files. I haven't a clue how Windows & Virtualbox is accessing what it sees as a virtual drive and then underlying that how the vbox drivers are using the system to get to the RAID. It would be interesting to set some program running, probably on a weekend or sometime when performance isn't so critical, and see what sort of data gets collected, assuming there's a program that does that sort of thing. Thanks, Mark -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
