re to Jeffrey J. Kosowsky <backuppc@ko...> - 2011-03-02 15:59 > If you are changing the appended rsync digest format for cpool > files using rsync, I think it might be helpful to also store the > uncompressed filesize in the digest There are several use cases > (including verifying rsync checksums where the filesize is required > to determine the blocksize) where I have needed to decompress the > entire file just to find out its size (and since I am in the pool > tree I don't have access to the attrib file to know its size). >
re to Jeffrey J. Kosowsky <backuppc@ko...> - 2011-03-03 16:40 > Alternatively, if you want the first time hack to work then you could > make the pool file name equal to: <md5sum>_<SHA-256sum> which would > still be smaller than SHA-512sum and I would wager that we are > unlikely ever to start seeing lots of files with simultaneous > collisions of the md5 and the SHA-256 checksums. In a sense, the > SHA-256 checksum would act like a unique chain suffix and since it > would always be there you never would have to actually decompress and > compare the files to see if a chain is necessary. Plus you then would > have two essentially independent checksums built into the file name. i would propose to extend it to <MD5>_<SHA_256>_NULL_<uncompressed_FILESIZE> by default and an option for (if user enables it :) <MD5>_<SHA256>_<SHA512>_<uncompressed_FILESIZE> maybe somebody wants to to recalculate the SHA512 sums afterwards (in idle time?) - therefore the "NULL" in the default name above indeed ... this would generate very long filenames: as for the name-length limit of 255 32_64_128_<filesize> meaning there would be space left for 27 more characters (10^26) so we could also append Filesizes of ... uuh ... wait ... 10^12 - Terabyte 10^15 - Petabyte 10^18 - Exabyte .... well ... very big files :) Having all kinds of checksums and sizes already calculated - these information may be reused for custom user-scripts like # integration testing of pool using md5, sha256 AND sha512 :) # appending .sha256 or sha512 files in archive-operations # post-dump integrity tests on client ... Greetings Mike ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ BackupPC-devel mailing list BackupPC-devel@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-devel Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
