On Monday 26 November 2007 11:23, Swen Schillig wrote: > On Sunday 25 November 2007 12:16, James Bottomley wrote: > > > > On Wed, 2007-10-31 at 11:33 +0100, Swen Schillig wrote: > > > From: Swen Schillig <swen@xxxxxxxxxxxx> > > > > > > add some statistics provided by the zFCP adapter to the sysfs > > > > > > The new zFCP adapter statistics provide a variety of information > > > about the virtual adapter (subchannel). In order to collect this information > > > the zFCP driver is extended on one side to query the adapter and > > > on the other side summarize certain values which can then be fetched on demand. > > > This information is made available via files(attributes) in the sysfs filesystem. > > > > > > The information provided by the new zFCP adapter statistics can be fetched > > > by reading from the following files in the sysfs filesystem > > > > > > /sys/class/scsi_host/host<n>/seconds_active > > > /sys/class/scsi_host/host<n>/requests > > > /sys/class/scsi_host/host<n>/megabytes > > > /sys/class/scsi_host/host<n>/utilization > > > > This lot all look like they belong in the FC transport class statistics > > (some even already exist there). > > They might look alike but they are not the same. The values provided through the FC transport > class always refer to the physical port whereas the new values here refer to a virtual adapter or subchannel. > The attributes provided here are all new and not covered or displayed anywhere else ! > > > > > > These are the statistics on a virtual adapter (subchannel) level. > > > In addition latency information is provided on a SCSI device level (LUN) which > > > can be found at the following location > > > > > > /sys/class/scsi_device/<H:C:T:L>/device/cmd_latency > > > /sys/class/scsi_device/<H:C:T:L>/device/read_latency > > > /sys/class/scsi_device/<H:C:T:L>/device/write_latency > > > > These look to duplicate to some degree the figures > > in /sys/block/<dev>/stat. Isn't the block device the best place to > > gather these, if they're useful? Since user latencies should probably > > include elevator times. > > Actually no, the latencies covered here are channel- and fabric-latencies grouped by scsi-devices > and not device-, scsi- or block-latencies. In contrast to the stats provided by the block-layer structure, > tape devices will be covered here as well . > > > > > James > > > > > > > > Cheers Swen > James were my answers, comments sufficient enough to apply my patch or is there still something missing required ? Thanks Cheers Swen - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
