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Notes on Backing Up My Hard Disk to Blu-Ray

Commands to Follow

To distribute files into more or less evenly sized buckets (as you would when having a backup span multiple disks:

dirsplit -e4 -s 25025314816b $PATH_TO_DIR_TO_BACK_UP

dirsplit generates multiple lists of which files will live on which disk. You can preview how much each disk space will ultimately be consumed with:

cut -d= -f2  $PATH_TO_DIRSPLIT_LIST | tr '\n' '\0'  | du -sch --files0-from=-

And you can use the following to generate the actual image files. Note that this will produce a hybrid UDF/ISO-9660 image file, files that are larger than 4 GB will appear to be truncated when read by drives that do not support UDF (see here and here.

mkisofs -udf -V $VOLNAME -D -r --joliet-long -graft-points -allow-limited-size -path-list $PATH_TO_DIRSPLIT_LIST -o $ISONAME

Once an image is generated, copy it down to Bruno (or equivalent desktop/laptop). Use scp to get a progress bar, and to eliminate some of the rsync overhead (not as necessary when there's only one file and file metadata doesn't matter).

scp [email protected]:$ISOPATH  .


Here are some approximate benchmarks for how long the above steps take:

Step Time Range
Making an ISO Image 3-5 minutes
Downloading an ISO Image 7-10 minutes
Burning an ISO Image 60-70 minutes

Speeds based off this LG Blu-Ray Writer.