[rrd-users] Error in database?

[Karl Fischer]

Mats Gustafsson wrote:
> Karl, I think you are right :-)
> I have been investigating this problem for over one month now, so I can
> tell you that your help is really appreciated :-)
> 
> I just tried with three databases: one that is 30 years long, one that
> is 20 rows long and one that is 50 years long. And in accordance with
> your prediction the two first are ok while the third one fails.
> 
> I guess that this explains why my databases all of a sudden stopped
> working one month ago. It must have been when the new rrdtool version
> was released in Gentoo and I updated to it.
> 
> My issue now is that I have been updating four databases (50 years long
> each) with information for almost two years now, and I'd rather not
> throw away all that data.
> 
> I see three possibilities:
> 1. Re-arrange my old databases and reduce them to 30 years length.
> 2. Wait for a new release of rrdtool that behaves in the same way as the
> old version.
> 3. Create new databases and throw away all my collected data.
> 
> What would you recommend?

Mats,

I'd dump the the databases and filter out the invalid rows ...

I quickly tried something that seems to work:

First I just eliminated the negative timestamps (leaving everything since 1970),
but my rrdtool complains when trying to access anything before 1980:

$ rrdtool fetch new.rrd AVERAGE --start 1/1/70
ERROR: the first entry to fetch should be after 1980

So I decided to remove the 1970s as well which leaves you with ~29 years.
(BTW: do you *really* believe you will run that system for 30+ years??)

rrdtool dump measure10.rrd \
| pcregrep -v '<!-- 19[567]\d-\d+-\d+ \d+:\d+:\d+ \w+ / -?\d+ -->' > new
rrdtool restore new new.rrd

did work for me - YMMV

hth

- Karl