Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f171.google.com ([209.85.223.171]:50573 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753364AbbAFSjx convert rfc822-to-8bit (ORCPT ); Tue, 6 Jan 2015 13:39:53 -0500 Received: by mail-ie0-f171.google.com with SMTP id ar1so4280666iec.2 for ; Tue, 06 Jan 2015 10:39:52 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) Subject: Re: a simple and scalable pNFS block layout server From: Weston Andros Adamson In-Reply-To: <20150106103708.70a06aba@synchrony.poochiereds.net> Date: Tue, 6 Jan 2015 13:39:50 -0500 Cc: Christoph Hellwig , "J. Bruce Fields" , linux-nfs list , linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com Message-Id: <9AFC48B6-B1DC-41CF-9D43-C27DF45A4809@primarydata.com> References: <1420561721-9150-1-git-send-email-hch@lst.de> <20150106173222.GF12067@fieldses.org> <20150106175611.GA16413@lst.de> <20150106103708.70a06aba@synchrony.poochiereds.net> To: Jeffrey Layton Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Jan 6, 2015, at 1:37 PM, Jeff Layton wrote: > > On Tue, 6 Jan 2015 18:56:11 +0100 > Christoph Hellwig wrote: > >> On Tue, Jan 06, 2015 at 12:32:22PM -0500, J. Bruce Fields wrote: >>> - do we have evidence that this is useful in its current form? >> >> What is your threshold for usefulness? It passes xfstests fine, and >> shows linear scalability with multiple clients that each have 10GB >> links. >> >>> - any advice on testing? Is there was some simple virtual setup >>> that would allow any loser with no special hardware (e.g., me) >>> to check whether they've broken the block server? >> >> Run two kvm VMs that share the same disk. Create an XFS filesystem >> on the MDS, and export it. If the client has blkmapd running (on Debian >> it needs to be started manually) it will use pNFS for accessing the >> filesystem. Verify that using the per-operation counters in >> /proc/self/mounstats. Repeat with additional clients as nessecary. >> >> Alternatively set up a simple iSCSI target using tgt or lio and >> connect to it from multiple clients. >> >>> - any debugging advice? E.g., have you checked if current >>> wireshark can handle the MDS traffic? >> >> The wireshare version I've used decoded the generic pNFS operations >> fine, but just dumps the layout specifics as hex data. >> >> Enable the trace points added in this series, they track all stateid >> interactions in the server. AdditÑ–onally the pnfs debug printks on >> client and server dump a lot of information. > > The wireshark decoder really only handles files layouts right now. Dros > has some patches to add flexfiles support too (once the spec is a bit > more finalized) and at that point it shouldn't be too hard to fix it to > handle block layout as well. I should be publishing these patches soon. The only holdup is waiting on the IANA layout type assignment. -dros