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Chelmsford city autumn cider festival 2013

The dates have been set for the Chelmsford city autumn cider festival 2013. It starts at 5pm on Thursday 3rd of October and finishes at 11pm on Saturday 5th of October. The event sees a return to the Triangle Club, Duke Street, Chelmsford, Essex CM1 1QH.

Please read on or see the official CAMRA site for further information.


Large file synchronization

Efficiently synchronize copies of a large sparse file locally. I deal with a large amount of large sparse files because of virtualization and other technologies. Because of their size, often a small number of blocks have data and, of these, a small number of blocks are changed and need to be backed up. Using a log-based (snapshotting) file system on USB 2 as a backup device, I only want to write blocks if absolutely necessary.

So what's the solution?  Some simple custom code that

  1. checks that both file sizes are identical;
  2. verifies that some metadata has changed (i.e time stamp, permissions or owner/group);
  3. reads both files block-by-block;
  4. writes only changed blocks to the destination file, and
  5. updates any changed metadata.