[rrd-users] rrdtool create graph very slow after system crash

[t***@email.de]

Hello everybody,

i'm using rrdtool to display some temperatures. It was working great until i
had bad blocks on my SD-Card. I'm using Raspbian on a Raspberry Pi B. I
copied the SD-Card to a new one, now the creation of rrdgraphs is very slow.
Before the BadBlocks the graph was created in under a second, now it takes
3(!) minutes. During creation the cpu load is at 100%

I can create dumpfiles from my rrd database without errors, so i think the
database is intact.

Has anyone an idea how to speedup the creation? Or maybe there are other
files corrupted, but i don't now which files are required for rrdtool to
work fast.



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[Stefan Parvu]

Post by t***@email.de
copied the SD-Card to a new one, now the creation of rrdgraphs is very slow.
Before the BadBlocks the graph was created in under a second, now it takes
3(!) minutes. During creation the cpu load is at 100%

you sure what you copied has not been corrupted ? Can you rrdtool create, update
via command line without issues or is it as well slow ?

When you say the the creation of an rrd file is slow, how are you creating the file:
rrdcgi, via perl, php or command line or how ?

Make sure as well the new sdcard is ok.

[Steve Shipway]

Post by t***@email.de
Before the BadBlocks the graph was created in under a second, now it takes
3(!) minutes. During creation the cpu load is at 100%

You might like to check the class rating of the SD card you are using in
your Pi. Anything under a 6 is too slow, and really, you should try for a
class 10 as RRDTool has a lot of IO and is usually IO bound. This can make
a big difference on the speed of things; also using the cheaper brands is
false economy... I've had problems onRasPi in the past using cheapo Apacer
class6 cards instead of the decent branded class10 ones.

Steve

Steve Shipway
***@auckland.ac.nz