Ibid 2009

The last I wrote about my backup tool, ibid, was three years ago (here; earlier post here), but I’ve continued making refinements to it. Then it was at version 24; now it’s at version 47 (download it here). Here are the changes since then, minus the uninteresting ones:

25. Add –maxfiles.
32. Don’t use Storable for the complete record structure; apparently a stringified form gets constructed in memory before it’s written to the file, which is disastrous for very large records. Use a custom streaming serialization method instead. Also, detect and reject unknown record versions.
35. Another major rewrite. This one does away with the old runtime data structures based on big, inefficient Perl hashes, replacing them with strings containing compact “pack”ed values. This change yields enormous runtime memory savings, which matters after a few hundred sessions and many tens of thousands of files have accumulated in your fileset record. Also fixed a few documentation bugs and eliminated some dead code.
36. Rename options for greater consistency: –limit (-l) is now –maxbytes (-b); –files (-f) is now –maxfiles (-f).
37. Report when one or the other limit (bytes or files) is reached.
38. Add –prune-sessions option.
41. Add new –single-file-size-limit option; renamed –maxbytes and –maxfiles to –session-size-limit and –session-files-limit, respectively. Switched from &foo() function-calling syntax to foo().
42. Add a new history-entry type: zero-length (“empty”) files. These are recorded in the session record but not copied to the archive, to save overhead.
43. Include <dev:ino> in –dump output when –verbose is supplied.
44. Support a device-map file, $HOME/.ibid/.devmap, for tracking a filesystem when its device number changes.
45. Document the .devmap file; add –trim-report; support “xz” compression of session files; support optional callbacks in foreach_name_history().
46. Add another level of depth to the “target” path for each new power of 10 in the session number. So session 7311 is rooted at TARGET/FILESET/7000/300/7311, and session 29582 is rooted at TARGET/FILESET/20000/9000/500/29582. Path elements that would start with a 0 are omitted; e.g., session 4006 is rooted at TARGET/FILESET/4000/4006, not at TARGET/FILESET/4000/000/4006.
47. Document –trim-report.

There’s still no home page for ibid, but at least now all ibid-related posts on my blog are grouped under the tag ibid.