X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=doc%2Frrd-beginners.txt;h=545ebb95b28246827384ee2845e9fa5d0e0cde48;hb=d9822df7ed5e8122cf3a62e4e99678e94007f504;hp=474912a99bfd1c14366262532a59bbc33fcebdd8;hpb=f714466e230f02e941349e0a91164d853a8006f4;p=pkg-rrdtool.git diff --git a/doc/rrd-beginners.txt b/doc/rrd-beginners.txt index 474912a..545ebb9 100644 --- a/doc/rrd-beginners.txt +++ b/doc/rrd-beginners.txt @@ -22,12 +22,12 @@ DDEESSCCRRIIPPTTIIOONN database, there are distinct differences between RRDtool databases and other databases as listed below: - · RRDtool stores data; that makes it a back-end tool. The RRDtool + · RRDtool stores data; that makes it a back-end tool. The RRDtool command set allows the creation of graphs; that makes it a front- end tool as well. Other databases just store data and can not create graphs. - · In case of linear databases, new data gets appended at the bottom + · In case of linear databases, new data gets appended at the bottom of the database table. Thus its size keeps on increasing, whereas the size of an RRDtool database is determined at creation time. Imagine an RRDtool database as the perimeter of a circle. Data is @@ -36,11 +36,11 @@ DDEESSCCRRIIPPTTIIOONN RRDtool database always remains constant. The name "Round Robin" stems from this behavior. - · Other databases store the values as supplied. RRDtool can be + · Other databases store the values as supplied. RRDtool can be configured to calculate the rate of change from the previous to the current value and store this information instead. - · Other databases get updated when values are supplied. The RRDtool + · Other databases get updated when values are supplied. The RRDtool database is structured in such a way that it needs data at predefined time intervals. If it does not get a new value during the interval, it stores an UNKNOWN value for that interval. So, @@ -103,7 +103,7 @@ DDEESSCCRRIIPPTTIIOONN ((PPDDPP)). In our example mentioned above, a new PDP is generated every 300 seconds. - Note, that if you do NOT supply new datapoints exactly every 300 + Note, that if you do NOT supply new data points exactly every 300 seconds, this is not a problem, RRDtool will interpolate the data accordingly. @@ -114,8 +114,8 @@ DDEESSCCRRIIPPTTIIOONN value is greater than 0). Traffic counters on a router are an ideal candidate for using COUNTER as DST. DERIVE is the same as COUNTER, but it allows negative values as well. If you want to see the rate of - _c_h_a_n_g_e in free diskspace on your server, then you might want to use the - DERIVE data type. ABSOLUTE also saves the rate of change, but it + _c_h_a_n_g_e in free disk space on your server, then you might want to use + the DERIVE data type. ABSOLUTE also saves the rate of change, but it assumes that the previous value is set to 0. The difference between the current and the previous value is always equal to the current value. Thus it just stores the current value divided by the step interval (300 @@ -315,4 +315,4 @@ AAUUTTHHOORR -1.3.999 2009-09-24 RRD-BEGINNERS(1) +1.4.8 2013-05-23 RRD-BEGINNERS(1)