element. As we are on a circle there is no beginning nor an end, you can
go on and on. After a while, all the available places will be used and
the process automatically reuses old locations. This way, the database
-will not grow in size and therefore requires no mainenance.
+will not grow in size and therefore requires no maintenance.
RRDtool works with with Round Robin Databases (RRDs). It stores and retrieves
data from them.
-=head2 What data can be put into an RDD ?
+=head2 What data can be put into an RRD ?
You name it, it will probably fit. You should be able to measure some value
at several points in time and provide this information to RRDtool. If you
First of all: read it again! You may have missed something.
If you are unable to compile the sources and you have a fairly common
-OS, it will probably not be the fault of RRDtool. There may be precompiled
+OS, it will probably not be the fault of RRDtool. There may be pre-compiled
versions around on the Internet. If they come from trusted sources, get
one of those.
If on the other hand the program works but does not give you the
and it tells you that the car has moved 12345 KM until that moment.
At 12:10 you look again, it reads 12357 KM. This means you have
traveled 12 KM in five minutes. A scientist would translate that
-into meters per second and this makes a nice comparison towards the
+into meters per second and this makes a nice comparison toward the
problem of (bytes per five minutes) versus (bits per second).
We traveled 12 kilometers which is 12000 meters. We did that in five
this document. It holds one data source (DS) named "speed" that gets
built from a counter. This counter is read every five minutes (default)
In the same database two round robin archives (RRAs) are kept, one
-averages the data every time it is read (eg there's nothing to average)
+averages the data every time it is read (e.g., there's nothing to average)
and keeps 24 samples (24 times 5 minutes is 2 hours). The other averages
-6 values (half hour) and contains 10 of such averages (eg 5 hours)
+6 values (half hour) and contains 10 of such averages (e.g., 5 hours)
The remaining options will be discussed later on.
RRDtool works with special time stamps coming from the UNIX world.
Most people will use the counter that keeps track
of octets (bytes) transfered by a network device so we have to do just
that. We will start with a description of how to collect data.
-Some people will make a remark that there are tools that can do this data
+Some people will make a remark that there are tools which can do this data
collection for you. They are right! However, I feel it is important that
you understand they are not necessary. When you have to determine why
things went wrong you need to know how they work.
Right, lets continue to the start of our OID: we had 1.3.6.1.2.1
From there, we are especially interested in the branch "interfaces"
-which has number 2 (eg 1.3.6.1.2.1.2 or 1.3.6.1.2.1.interfaces).
+which has number 2 (e.g., 1.3.6.1.2.1.2 or 1.3.6.1.2.1.interfaces).
First, we have to get some SNMP program. First look if there is a
pre-compiled package available for your OS. This is the preferred way.
get a totally different picture. You would see the same values on the
average and maximum graphs (provided I measured every 300 seconds).
You would be able to see when I stopped, when I was in top gear, when
-I drove over fast hiways etc. The granularity of the data is much
+I drove over fast highways etc. The granularity of the data is much
higher, so you can see more. However, this takes 12 samples per hour,
or 288 values per day, so it would be too much to keep for a long
period of time. Therefore we average it, eventually to one value per
so called hot-spot and the exhaust. These values are not counters.
If I take the difference of the two samples and divide that by
300 seconds I would be asking for the temperature change per second.
-Hopefully this is zero! If not, the computerroom is on fire :)
+Hopefully this is zero! If not, the computer room is on fire :)
So, what can we do ? We can tell RRDtool to store the values we measure
directly as they are (this is not entirely true but close enough). The
=item *
-Line B is of type gauge. These are "real" values so they should match
+Line B is of type GAUGE. These are "real" values so they should match
what we put in: a sort of a wave.
=item *
interval is 297 seconds and also the counter increased with 297. Again
RRDtool alters the value and stores 300 as it should be.
- in the RDD in reality
+ in the RRD in reality
time+000: 0 delta="U" time+000: 0 delta="U"
time+300: 300 delta=300 time+300: 300 delta=300
projects / rrdtool.git / blobdiff