vmstats | vm statistics , gathered from a geth instance | DevOps library

It's a known limitation of bcc (cf. iovisor/bcc#1072). Basically, the maximum number of active probes is set too low for your tracing context and you are thus missing some return probes.

In bcc, the maxactive value (maximum number of active probes, see documentation extract below) is left to its default value. Since Alban Crequy's patch to the Linux kernel (cf. iovisor/bcc#1072), it's possible to change the maxactive value when attaching probes through debugfs. That new API hasn't been exposed through bcc's yet though. I'll try to send a patch to that effect this week.

While the probed function is executing, its return address is stored in an object of type kretprobe_instance. Before calling register_kretprobe(), the user sets the maxactive field of the kretprobe struct to specify how many instances of the specified function can be probed simultaneously. register_kretprobe() pre-allocates the indicated number of kretprobe_instance objects.

For example, if the function is non-recursive and is called with a spinlock held, maxactive = 1 should be enough. If the function is non-recursive and can never relinquish the CPU (e.g., via a semaphore or preemption), NR_CPUS should be enough. If maxactive <= 0, it is set to a default value. If CONFIG_PREEMPT is enabled, the default is max(10, 2*NR_CPUS). Otherwise, the default is NR_CPUS.

The 5-minute granularity you want is only available for the past 24 hours. Stats older than that are rolled up into the 30-minute intervals you observe (and eventually rolled up further).

Archived stats

"are aggregations (rollups) of the real-time stats. They are aggregated at different sampling intervals and stored in the database. We follow the MRTG standard.

Past day: past day stats take the real-time stats and roll them up so that there is 1 data point for every 5 minutes. Thus, there are 12 data points per hour and 288 per day.

Past week: past week stats take the past day stats and roll them up so that there is 1 data point for every 30 minutes. Thus, there are 48 data points per day and 336 per week.

Past month: past month stats take the past week stats and roll them up so there is 1 data point per 2 hours. Thus, there are 12 data points per day and 360 per month (30-day month). Past year: past year stats take the past month stats and roll them up so there is 1 data point per day. Thus, there are 365 data points per year."

the usb 4-1 is the USB port number, stat urb : status -32 means that urb ( USB request block ) reports error -32 ( broken pipe ) cf. http://www.makelinux.net/ldd3/chp-13-sect-3 for the urb and http://www-numi.fnal.gov/offline_software/srt_public_context/WebDocs/Errors/unix_system_errors.html for the error code

very likely the problem is the UAS module ( https://en.wikipedia.org/wiki/USB_Attached_SCSI ), see https://bbs.archlinux.org/viewtopic.php?id=183190, https://bbs.archlinux.org/viewtopic.php?id=183723

a solution for archlinux is in https://bbs.archlinux.org/viewtopic.php?id=183190 in Da_Coynul's answer, it 'blacklists' the uas module for the specific SCSI drive by configuring the usb-storage module :

I was able to get my external drive working again by telling the usb-storage module to ignore uas for the device. Here is how to do it:

First, create a file named ignore_uas.conf in the /etc/modprobe.d directory containing the following*