There probably was a change in the defaults for creation quite a while back (after yours were created), but this only affects new files.

Interestingly, someone on IRC had the same issue 2 weeks or so ago (unless this was also you?) but the cause is unknown - as Adam says, if the file exists, we only run "rrdtool update" on it.

Tom

On 12/01/2014 13:13, Robert Williams wrote:

Hi,

Thanks for that - however I find this interesting, the RRDs are a different size now compared to the restored versions:

For a normal port:

1,078,896 port-10148.rrd.restore (the backup/restored version)

1,739,144 port-10148.rrd (the empty created at midnight version)

For netstats-icmp:

1,218,600 netstats-icmp.rrd.restore (original)

3,013,472 netstats-icmp.rrd (new empty one)

So an increase for every file occurred at midnight, we have nothing else running on this server, so no reason for something to go and pick out all similar hardware and delete their rrds.

I then checked the rrd content and found a large difference in the rra/row sizes and the number of actual rra’s:

# rrdtool info port-10148.rrd.restore | grep .rows <- the smaller restored version from yesterday

rra[0].rows = 2016

rra[1].rows = 2976

rra[2].rows = 1440

rra[3].rows = 1440

rra[4].rows = 1440

rra[5].rows = 360

rra[6].rows = 1440

rra[7].rows = 1440

rra[8].rows = 360

rra[9].rows = 1440

# rrdtool info port-10148.rrd | grep .rows <- the larger created-at-midnight version

rra[0].rows = 2400

rra[1].rows = 1200

rra[2].rows = 1200

rra[3].rows = 1200

rra[4].rows = 600

rra[5].rows = 700

rra[6].rows = 775

rra[7].rows = 797

I’ve checked further back in time and the files have been the same (smaller) size for as far back as our backups go (several months) – so something caused it to change the layout of the rrd file, only for these specific hosts, overnight.

I’m a bit lost with this one, any ideas?

From: observium [mailto:observium-bounces@observium.org] On Behalf Of Adam Armstrong
Sent: 12 January 2014 11:51
To: Observium Network Observation System
Subject: Re: [Observium] Sudden loss of history

Observium doesn't have the ability to do this. Once the RRDs exist, it can't recreate them. Either they were removed or deleted, and were then recreated by observium.

Adam.

Robert Williams

Custodian Data Centre

Email: Robert@CustodianDC.com

http://www.CustodianDC.com
_______________________________________________
observium mailing list
observium@observium.org
http://postman.memetic.org/cgi-bin/mailman/listinfo/observium