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The following section details the extremely important issue of archiving. In the first part, I detail the reasoning and strategy. Then, I go on to discuss the automated workflow I use to ensure I don't have to worry about my hard-earned photo collection.
My Previous Backup Method
- Every day, my photo collection is mirrored onto another physical hard drive at 6:00 AM. The likelihood of two drives failing at the same time are not great, and it helps ensure that one has at least a recent backup to work from.
- In addition, the entire collection is also archived by incremental backup to a DVDR on Monday & Fridays at 8:00 PM. If I leave the DVDR in the drive, the backup will be done automatically as well.
- Create two copies of the backup data to DVD-R. One set is kept at home, and the other is kept at a remote location.
- Every month or so, I perform a full or differential backup to DVD-R. Instead of relying on a large number of incremental backup sets, I prefer to restart the backup from a clean copy every so often.
- Keep at least one old backup set at a remote location (full plus any differential and incremental discs) stored, and destroy previous sets.
The collection is defined as my entire hierarchy of photos in addition to the IMatch database (which contains all of the categories and tags).
My Current Backup Method
I have long since searched for an affordable way to protect my collection without the hassle of burning DVDs then transporting them off-site. The manual transport is the problematic part as it is all to lazy to put it off. So, I created my own offsite backup for free! This has been a fantastic improvement, both in automation and piece of mind.
- Every night, my photo collection is copied via FTP to an offsite hard drive automatically. This backup is incremental and preserves old version sets of photos and data. By offsite, it means far away from my home!
- The same process is performed on my documents, website and other files of importance.
- All files are protected by encryption with AES before backup.
- Once every month or so I do a full backup to an external drive.
The beauty of this setup is that it is completely automatic. I don't need to be involved in the process anymore (so I won't get lazy and forget), plus it protects me from disasters around the home (where onsite hard drives or DVDs could get damaged / stolen).
Please have a look at my article on FTP Offsite Backup. Note that I do not pay for a service -- this simply uses my own hard drive (NAS) stored at another location and configured appropriately.
Both backup processes also involve verification, reading back the data to ensure that everything copied to the medium without error.
Nearly all backup programs can be classified into two variants: those that create drive images and those that create file-based backups.
The difference in backup styles is important to understand as it has implications on how a photo catalog can be archived. The following summarizes the main differences between each style:
- Drive Image
Imaging is a process whereby an exact duplicate of the contents of a drive are created on another drive (or spanned across removable media). It should be noted that imaging is almost always done at the disk-level, not on the individual file level. Therefore, with imaging, you generally don't have any options with regards to which directories or files you want to archive. This is a fundamental point, as it means that you must copy the entire drive, and cannot ignore certain directories or file types.
- Full Backup
Unlike imaging, a full backup is almost always file-based, and it copies a selection of the drive's directory hierarchy. It also usually supports exclusion rules (ie. not copying over the Thumbs.db files) and the archive set can span multiple drives (eg. some directories from drive C: and others from E:). A full backup copies over all of the files in the backup set, and it pays no attention to modification dates, archive bits, etc.
- Differential Backup
Differential backups copy over the files that have changed since the last full backup. After performing a number of incremental backups, the backup data will eventually be spanning a large number of incremental sets in addition to the last full backup. This means that recovering the full set of files might involve using a large number of backup sets or discs. This has the disadvantage in that a failure in one disc might destroy the entire restore process. When a differential set is created, all of these incremental discs are essentially "thrown out" and a fresh start is created of changes since the last full backup. If not many of the original files have been changed, it's worth performing differential backups periodically. If a large percentage of the source files change, then it is better to recreate the full backup set instead.
- Incremental Backup
Incremental backups copy over the files that have changed since the last backup, whether it was a full, differential or incremental backup. This has the advantage in creating the smallest and fastest backup to keep "up-to-date". It has the disadvantage over time of distributing the new or changed files over many backup sets or discs. An ideal strategy is to use an incremental set regularly and then a full or differential periodically.
Mirrors simply keep a synchronized / up-to-date copy of specified file hierarchy across multiple drives. A change on one drive (usually the master or source) is reflected in the destination. Some programs will automatically monitor the source directory for changes, others need to be invoked periodically or scheduled. Unlike normal backups, mirroring has the disadvantage in that a corruption in the original set (the source) will eventually copy over the mirror destination set. A smarter mirror system will take an additional step with changed files and create a subdirectory to preserve the history of changes to each file. See the section on changesets.
Backup storage: Standard or Proprietary
Select a section to enter:
- Ultimate archiving strategies: RAID
- Offsite FTP
- Mirroring with a smart twist: changesets
- Review: XXCopy
- Media: CD-R, DVD-R, archival quality? Media lifespan?