See also data integrity over time and with OS changes.
An overlooked aspect of data management is data integrity : the files are intact tomorrow, a year from now, on the original drive and backup drive (s), or maybe even on a DVD or BluRay . Or after being transferred over a network.
Knowing that files / data is intact without damage is an important part of system recovery / updating / backup / archiving. In some situations it may be mandatory (registration). The more valuable the data is, the more important it is to assess the risk of loss, including loss of file corruption, and file recovery (not to mention viruses and software errors and user errors).
"Data" can mean image files (JPEG, TIF, PSD / PSB, etc.) or video clips or projects, Lightroom directories, etc. Or it can mean spreadsheets, word processing files, accounting data, and so on. Knowing that these files are 1
How can data be damaged? Disk errors, software errors in applications or drivers or the system itself can occur. Furthermore, the "damage" can be user-sanitized: saving over or replacing / deleting a file inadvertently. Only having a "warning flag" can be useful when you notice that "no expected changes" have been violated.
For example, assume that a new computer system has been acquired and various stations have to be transferred over. Or that you've upgraded to a newer and bigger hard drive. Or switched SSDs. Or there is a need to recover from a backup. Or that you burned files to a DVD or BluRay are they intact without changes? Even RAID-5 with its parity data does not validate files when reads them, and a validation pass is over the entire volume without the selectivity of the desired file (s).
Enter IntegrityChecker part of diglloydTools: At any time, files of all types can be controlled against a previously calculated "hash", a cryptographic number unique to the file. If it's wrong, the file has been modified, somehow. This check can be done at any time: on the original or on a 1000-generation copy of that file. The only requirement is that the hash must be calculated once and remain in the same folder as the file for later reference.
How it works with IntegrityChecker.
IntegrityChecker calculates a SHA1 cryptographic hash for each file in a folder, stores these hash numbers in a hidden ".ic" file in that folder. Thus, all files in the folder have a "hash value" that the current state can be controlled on.
The process can be run on folders or a whole volume.
- Run (calculates and writes the hash values for each file in each folder to a hidden ".ic" file in that folder) . on the original files
- Make the copy or backup or burn the DVD / BluRay or whatever (this of course follows the hidden ".ic" file in each folder) .
- At a later date (tomorrow or a year later), run (this recomputes the hashens and compares with the values in the ".ic" file) . on a backup or copy
For example, some professional photographers burn DVDs or BluRay discs that contain folders that IntegrityChecker has run on; These plates carry the ".ic" file in each folder and can be confirmed at any time. There are many such uses.
Both command lines (Terminal) and GUI versions are provided. The GUI is basic, but internals are what matters: One of the most effective multi-threaded programs of any kind you will ever find. IntegrityChecker runs as fast as the drive and CPUs can go. Available commands include & # 39; status & # 39 ;, & # 39; update & # 39 ;, & # 39; verify & # 39 ;, & # 39; update all & # 39; and & # 39; clean & # 39 ;.
See how to safely transfer data or verify backups and also data integrity verification.
Worth doing or happy?
For many users of the computer, the consequences are of little importance if some thing goes wrong: a song, a picture, a particular document; no big deal. But even such users would be sorry to lose years of images-bugs in software (gray swan?) May have widespread significance; Data integrity control is a sensible control of assumptions.
However, in the economic and compulsory academic sense, professionals must assess the final process they use. When the data is a livelihood, the attention to data integrity takes new meaning.
The greater the value of the data and the greater the time interval over which the data has value, the more important it is to implement processes that minimize the chances of loss, for many years the storage format is likely to Changes with transitions and copying etc. It is also certain that a backup that has been recovered from a crash is valid, some of the connectors are removed from a crash.