That is an interesting thought. I did check the aggregate CPU utilization (Dual 6-core 2.0GHz Xeon, E5-2630L) and overall it looks fine with a load average below 0.5 during transfers. However, I have not checked if there is a single thread that is blocking the process. I guess the cheap way to verify your assumption is to run the process on a faster processor. If the throughput goes up with the speed of the CPU that would indicate we're on the right track. I think we have a couple of E-2637v2's laying around, let me see if I can get those swapped in.
W Willem R. van den Berge Chief Technology Officer [email protected] Altep, Inc | Innovative Litigation Solutions 7450 Remcon Circle, El Paso, Texas 79912 800 263-0940 Toll Free 915 533-8722 915 533-8895 Fax www.altep.com Privacy/Privilege: This message and any files transmitted with it are intended for the sole use of the individual or entity to which they are addressed, and contain information sent at the direction of counsel that is subject to The Privacy Act, or that is privileged, confidential, and exempt from disclosure. If you are not the intended recipient, or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination or distribution, including forwarding, copying or printing of this communication, is strictly prohibited. If you have received this communication in error, please notify us immediately by telephone, and delete the original message and any attached files immediately. Altep, Inc., its subsidiaries and affiliates will not be held liable for damage or loss resulting from the unintended or unauthorized use of any information contained in this email or any attached files, or as a result of any additions or dele tions of information originally contained therein. -----Original Message----- From: Jim Klimov [mailto:[email protected]] Sent: Monday, December 09, 2013 1:15 PM To: [email protected] Subject: Re: [OpenIndiana-discuss] zsf send/receive performance Reading your description, I thought "can it be a single-CPU performance issue?" Perhaps, decompressing your datasets (or compressing upon write - though the /dev/null experiment rules that out), or building the stream, or any other step in your data path, might for some reason be a single-threaded task. Running several in parallel splits them across many cores, but one is slow. Not being a ZFS developer, I am not ready to check and point the place in code where that guess might be (dis-)proved, but at least I'd start digging (and asking) with such an assumption :) At least, there are many things in parallel IT processing that are made fast by sheer scale of concurrent independent tasks, rather than (expensively) trying to parallelize the code inside. And on average the cheap approach pays off ;) //Jim _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
