Brief Data

This format does NOT include data for any individual devices such as cpu, disk, network, nfs, lustre, process, slabs or tcp. If you do select any one of them collectl will force --verbose format.

CPU Data, collectl -sc

#<--------CPU-------->
#cpu sys inter  ctxsw

cpu	Percent of time the cpu was busy during the current interval averaged across all CPUs and is actually the total percentage of time the CPU in one of the following: system, user, nice, irq, soft-irq and steal. Note that this does NOT include time spend in I/O wait.
sys	Percentage of time the cpu was executing in system mode during the current interval. This includes all those modes as above except user and nice to to determine the amount of time spent as a user you need to subtract these from the total cpu field.
inter	Total number of interrupts/sec.
ctxsw	Total number of context switches/sec.

Disk, collectl -sd

There are currently 3 places that collectl can gather disk performance data from. Fortunately you don't really have to worry about it unless you really care. In the 2.4 kernel, the most detailed disk data is stored in /proc/partitions and that is indeed where collectl tries to get it from. However, some older kernels may not have been configured to provide this data in which case collectl will grab less detailed data from /proc/stat. In the 2.6 kernel, performance data has been moved from /proc/partitions to /proc/diskstats and so it is gathered from there.

In any event, regardless of where the data comes from it is all presented in the same format. This means some fields may be 0 (2.4 kernels and /proc/stat) when displayed with --verbose, but it is expected few systems will fall into this category.

#<---------------Disks---------------->
#KBRead  Reads  Size KBWrit Writes Size

KBRead	KB read/sec
Reads	Number of reads/sec
Size	Average read size in KB. This field only included if --iosize specified
KBWrite	KB written/sec
Writes	Number of writes/sec
Size	Average write size in KB. This field only included if --iosize specified

Infiniband, collectl -sx

#<---------------InfiniBand--------------->
#  KBin  pktIn Size  KBOut pktOut Size Errs

KBin	KB received/sec.
pckIn	Packets received/sec.
size	Average incoming packet size in KB. This field is only included if --iosize included
KBout	KB sent/sec.
pktOut	Packets sent/sec.
size	Average outgoing packet size in KB. This field is only included if --iosize included
Errs	Count of current errors. Since these are typically infrequent, it is felt that reporting them as a rate would result in either not seeing them OR round-off hiding their values.

Lustre

Lustre data actually falls into one of 3 categories - client, mds and oss. Collectl determines the type of system it is running on (a system can have multiple personalities) and reports on all it finds, unless specifically selected via -L.

Lustre Client, collectl -sl

#<-------Lustre Client------>
# Reads KBRead Writes KBWrite

Reads	Reads/sec delivered to the client, not necessarily from the lustre storage servers.
KBRead	KB/sec delivered to the client.
Writes	Writes/sec delievered to the storage servers.
KBWrite	KB Writes/sec delievered to the storage servers.

The following format of lustre client data is selected by including -OR and adds readahead statistics to the previous four.

#<-------------Lustre Client-------------->
# Reads KBRead Writes KBWrite   Hits Misses

Reads	Reads/sec delivered to the client, not necessarily from the lustre storage servers.
KBRead	KB/sec delivered to the client.
Writes	Writes/sec delievered to the storage servers.
KBWrite	KB Writes/sec delievered to the storage servers.
Hits	Number of reads/sec from the lustre prefetch cache.
Misses	Number of misses/sec from the prefetch cache which must then be satisfied by reading from the storage servers.

Lustre MDS (Meta-Data Server)

#<--------Lustre MDS-------->
#mdsCls Getatt  Reint   sync

mdsCls	Number of file closes/sec.
Getatt	Number of getattrs/sec.
Reint	Reintegrated operations/sec which are inode modifications and unklinks.
Sync	Number of syncs/sec.

Lustre OSS (Object Storage Server), collectl -sc

#<--------Lustre OST------->
#KBRead  Reads KBWrit Writes

KBRead	KB/sec read
Reads	Reads/sec
KBWrite	KB/sec written
Writes	Writes/sec

Memory, collectl -sm

#<-----------Memory---------->
#free buff cach inac slab  map

free	Total free memory, which unfortunately is NOT the difference between total memory and the following amounts allocated to used memory.
buff	Memory used as system buffers.
cach	This is also commonly known as the file system buffer cache as buffered I/O uses this memory to cache the data.
inac	Inactive memory.
slab	Total memory allocated to slabs.
map	Total mapped memory, which include AnonPages.

Network, collectl -sn

#<---------------Network--------------->
#netKBi pkt-in size netKBo pkt-out size

netKBi	KB received/sec over all real network interfaces and therefore excludes 'lo' and 'sit'.
pkt-in	Packets received/sec over all real network interfaces.
size	Average incoming packet size in bytes. This field is only included if --iosize specified
netKBo	KB sent/sec over all real network interfaces.
pkt-out	Packets sent/sec over all real network interfaces.
size	Average outgoing packet size in bytes. This field is only included if --iosize specified

NFS, collectl -sf

#<--NFS Svr Summary-->
#  read  write  calls

read	Total nfs reads/sec.
write	Total nfs writes/sec.
calls	Total nfs calls/sec.

Slabs, collectl -sy

#<----slab---->
# Alloc   Bytes

Alloc	Total Number of slabs allocated
Bytes	Total Number of bytes allocated as slabs

Sockets, collectl -ss

#<------Sockets----->
#  Tcp  Udp  Raw Frag

Tcp	Total TCP sockets currently in use.
Udp	Total UDP sockets currently in use.
Raw	Total RAW sockets currently in use.
Frag	Total number of IP fragments queues currently in use.

TCP, collectl -st

#<------------TCP------------>
#PureAcks HPAcks   Loss FTrans

PureAcks	ACKs/sec that only contain acks (ie no data).
HPAcks	Fast-path acks/sec.
Loss	Packets/sec TCP thinks have been lost coming in.
FTrans	Fast retransmissions/sec.