XFS on Irix had a feature similar to QoS, called GRIO (guaranteed rate I/O), where applications could reserve a given bandwidth.
http://www.sgistuff.net/software/irixintro/documents/xfs-whitepaper.html Sounds somewhat similar to QoS, but focused on giving applications guaranteed bandwidth, not iops. -jf ons. 15. jun. 2016 kl. 00.08 skrev Marc A Kaplan <[email protected]>: > Yes, in QOS for 4.2.0 there are some simple assumptions that may not make > a lot of sense in some configurations, especially configurations with many > (100s) of nodes mounting the same file system... You can try out what > you suggested and in 4.2.0 I think it will pretty much work as you suggest > -- essentially you are allocating 466 maintenance iops to every node, > knowing that most of those nodes will not be using their allocation of IOPS. > > In later releases, you may find that we will address some of these kinds > of quirks in QOS. > > QOS is a new feature for GPFS, and I don't think you'll find anything like > it in any commercial file system offering. (Correct me with example(s) if > I am wrong on this point.) > So think of it as "release 1.0" (of QOS) and let us know how well it works > for you and how it might be improved.... > > --marc of Spectrum(GP)FS > > > > From: "Buterbaugh, Kevin L" <[email protected]> > To: gpfsug main discussion list <[email protected]> > Date: 06/14/2016 04:50 PM > Subject: [gpfsug-discuss] QoS question > Sent by: [email protected] > ------------------------------ > > > > Hi All, > > We have recently upgraded to GPFS 4.2.0-3 and so I am getting ready to > dive into my first attempts at using the new QoS features. I want to make > sure I am understanding the documentation: > > "The IOPS values that you set in an mmchqos command apply to all I/O > operations that are issued by all the nodes that have the specified file > system mounted. You should adjust your allocations of IOPS accordingly. > > For example, if you 600 IOPS to the maintenance class, and there are six > nodes that have the file system mounted, then QoS allocates 100 IOPS to the > maintenance class of each node. If you then run maintenance commands that > affect only three of the nodes, the commands runs with an actual allocation > of 300 IOPS, or 100 IOPS per node. To run maintenance commands that affect > three nodes with an actual allotment of 600 IOPS, or 200 per node, allocate > 1200 IOPS to the maintenanceclass. " > > We have a ~700 node cluster with 15 NSD servers. Here’s how I interpret > the above assuming that I have determined that I want to allow 7,000 IOPs … > please correct me if I’m wrong... > > 7,000 IOPs / 700 nodes would be 10 IOPs per node. > > But I want those 7,000 IOPs to be divided amongst my 15 NSD servers that > are going to be doing the maintenance (a restripe, for example), so 7,000 / > 15 = 466.67. > > 466.67 * 700 (nodes in cluster) = 326,666.67. So I would allocate 326,666 > IOPs to the maintenance class? > > Thanks in advance… > > Kevin > — > Kevin Buterbaugh - Senior System Administrator > Vanderbilt University - Advanced Computing Center for Research and > Education > > *[email protected]* <[email protected]>- > (615)875-9633 > > > > > _______________________________________________ > gpfsug-discuss mailing list > gpfsug-discuss at spectrumscale.org > http://gpfsug.org/mailman/listinfo/gpfsug-discuss > > > _______________________________________________ > gpfsug-discuss mailing list > gpfsug-discuss at spectrumscale.org > http://gpfsug.org/mailman/listinfo/gpfsug-discuss >
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