[rrd-users] rrdtool resize corrupts timestamps in both 1.3.9 and 1.4.7

[Jo Rhett]

On Jul 16, 2012, at 10:28 PM, Ryan Kubica wrote:
> I've never run into this issue before (and store a lot of data) and on 64bit hosts, but:
> 
> 	a) I always compile rrdtool not use stock OS rpm

This isn't a common situation -- most people use RPMs, and that means that this is broken for most people.  Also we are using a package that bundles a binary image of rrdtool, another situation where many people won't or can't change it out.

> 	b) It is compiled with mmap()
> 	c) I only resize an rrdtool file when it's not being written to (my apps write daemon does the resize in place as a task.)

That's not a choice I get. This system is too critical to stop updates long enough for that to happen. (although I have been digging around in the code to see if there is any locking mechanism that rrdtool will honor)

> and it works for resizes just fine (just tested manually), I grew RRA 0 by 2x.
> 
> [tmp]$ grep 1340865780 *xml
> Epic_io_90.xml:			<!-- 2012-06-28 06:43:00 UTC / 1340865780 --> <row><v>9.7033939036e+04</v></row>
> resize.xml:			<!-- 2012-06-28 06:43:00 UTC / 1340865780 --> <row><v>9.7033939036e+04</v></row>
> 
> [tmp]$ grep 1340865840 *xml
> Epic_io_90.xml:			<!-- 2012-06-28 06:44:00 UTC / 1340865840 --> <row><v>9.7633476991e+04</v></row>
> resize.xml:			<!-- 2012-06-28 06:44:00 UTC / 1340865840 --> <row><v>9.7633476991e+04</v></row>

Curious, what OS / kernel are you using?

-- 
Jo Rhett
Net Consonance : net philanthropy to improve open source and internet projects.



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