[rrd-developers] interleaving RRD files, RRDfs perhaps?

Daniel.Pocock at barclayscapital.com Daniel.Pocock at barclayscapital.com
Thu Oct 2 11:59:46 CEST 2008

With a system such as Ganglia, there are many RRD files all created with
exactly the same parameters.

While rrdcached provides benefits by caching updates to each file, we
still see lots of small 4kb random access writes to the SAN.

Has anyone considered the possibility of aggregating multiple RRD files
with identical RRAs into a single file, or even some kind of
pseudo-filesystem?  This would mean that each disk block would contain
data from many RRDs common to a specific update time.  There would be a
dramatic improvement in write speed, as the OS and SAN would be caching
the blocks relating to the current time period, rather than racing back
and forth all over the disk.

It would be particularly desirable to be able to tune the block size
used for interleaving, so that it could maximise filesystem and SAN



This e-mail may contain information that is confidential, privileged or otherwise protected from disclosure. If you are not an intended recipient of this e-mail, do not duplicate or redistribute it by any means. Please delete it and any attachments and notify the sender that you have received it in error. Unless specifically indicated, this e-mail is not an offer to buy or sell or a solicitation to buy or sell any securities, investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Barclays. Any views or opinions presented are solely those of the author and do not necessarily represent those of Barclays. This e-mail is subject to terms available at the following link: www.barcap.com/emaildisclaimer. By messaging with Barclays you consent to the foregoing.  Barclays Capital is the investment banking division of Barclays Bank PLC, a company registered in England (number 1026167) with its registered office at 1 Churchill Place, London, E14 5HP.  This email may relate to or be sent from other members of the Barclays Group.

More information about the rrd-developers mailing list