On Thu, Jun 2, 2011 at 5:20 AM, John Drescher <dresche...@gmail.com> wrote: > On Thu, Jun 2, 2011 at 5:10 AM, Ralf Gross <ralf-li...@ralfgross.de> wrote: >> John Drescher schrieb: >>> On Thu, Jun 2, 2011 at 4:05 AM, Ralf Gross <ralf-li...@ralfgross.de> wrote: >>> > Rickifer Barros schrieb: >>> >> Yes John... >>> >> >>> >> Now, I think that I understood perfectly and I have tested it too. >>> >> >>> >> VolumeToCatalog = Compares the files in a Storage Volume with the >>> >> Catalog; >>> > >>> > >>> > VolumeToCatalog does not read the file content and compares it, it just >>> > reads the attributs and compares them (md5sum....). >>> > >>> > quote: >>> > http://www.bacula.org/en/dev-manual/main/main/Configuring_Director.html >>> > >>> > VolumeToCatalog >>> > This level causes Bacula to read the file attribute data written >>> > to the Volume from the last Job. The file attribute data are compared >>> > to the values saved in the Catalog database and any differences are >>> > reported. This is similar to the Catalog level except that instead of >>> > comparing the disk file attributes to the catalog database, the >>> > attribute data written to the Volume is read and compared to the >>> > catalog database. >>> >>> This part to me says it does compare the data on the volume with the >>> hash MD5/SHA1 that is stored in the database. >> >> >> I always thought that a VolumeToCatalog job would not read the >> data written to the volume and calculate the md5sum again. Instead it >> would just read the file attributes that were written to the volume and >> compare that with the attributes in the catalog. >> >> At least the volume format described in developers.pdf suggest that the >> md5sum >> information is part of the data stream. >> >> 10.7 Record Header >> >> #define STREAM_UNIX_ATTRIBUTES 1 /* Generic Unix attributes */ >> #define STREAM_FILE_DATA 2 /* Standard uncompressed data */ >> #define STREAM_MD5_SIGNATURE 3 /* MD5 signature for the file */ >> #define STREAM_GZIP_DATA 4 /* GZip compressed file data */ >> /* Extended Unix attributes with Win32 Extended data. Deprecated. */ >> #define STREAM_UNIX_ATTRIBUTES_EX 5 /* Extended Unix attr for Win32 EX */ >> #define STREAM_SPARSE_DATA 6 /* Sparse data stream */ >> #define STREAM_SPARSE_GZIP_DATA 7 >> #define STREAM_PROGRAM_NAMES 8 /* program names for program data */ >> #define STREAM_PROGRAM_DATA 9 /* Data needing program */ >> #define STREAM_SHA1_SIGNATURE 10 /* SHA1 signature for the file */ >> #define STREAM_WIN32_DATA 11 /* Win32 BackupRead data */ >> #define STREAM_WIN32_GZIP_DATA 12 /* Gzipped Win32 BackupRead data */ >> #define STREAM_MACOS_FORK_DATA 13 /* Mac resource fork */ >> #define STREAM_HFSPLUS_ATTRIBUTES 14 /* Mac OS extra attributes */ >> #define STREAM_UNIX_ATTRIBUTES_ACCESS_ACL 15 /* Standard ACL attributes on >> UNIX */ >> #define STREAM_UNIX_ATTRIBUTES_DEFAULT_ACL 16 /* Default ACL attributes on >> UNIX */ >> >> >> >> So I think that only the md5sums on the volume are compared with the md5sums >> in >> the catalog. If the file data on the volume was damaged somehow this could >> not >> be detected. >> > > The reason I think it is reading the volume is the comparison to the > Catalog level which has to read the filesystem data to compare that to > the md5sum in the catalog. > > http://bacula.org/5.0.x-manuals/en/main/main/Using_Bacula_Improve_Comput.html >
I guess I can test this by creating an uncompressed disk volume for a fileset containing a single text file then corrupting the data part of the bacula volume and see what it does.. John ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
