I overwrote a savegame with another by accident. Is there any way of recovering the overwritten save file?
Quote from: Taurus on July 24, 2015, 04:27:33 PM
I overwrote a savegame with another by accident. Is there any way of recovering the overwritten save file?
Not using Simutrans itself. You can look into recovering lost files in general, but the only reliable way of recovering lost files is to take backups before they are lost. I have no experience with recovery software since the undelete command in MS-DOS back in the early/mid 1990s, and that was for deleted files, not overwritten files. The most important thing when something needs to be rescued on a file system, is to stop using that file system. Continued use will eventually result in the data being physically overwritten. At that point, I'm not sure even a professional data recovery company can recover it, and they are seriously expensive.
There are two kinds of people: those who have lost data, and those that are going to lose data.
Thanks for the help. Was able to recover the savegame with Piriform Recuva.
Good to hear. Consider yourself lucky, although it's probably not quite pure chance that the data was still hanging around on the disk somewhere. It also shows that deleting a file doesn't mean the data is gone, if anyone ever wants to get rid of something forever.
QuoteIt also shows that deleting a file doesn't mean the data is gone, if anyone ever wants to get rid of something forever.
That entirely depends on the backing storage and the OS. Windows starting with Vista can use shadow copies to keep copies of modified files such that you can roll the changes back. This will always work on drives it is enabled on as long as there is sufficient free space that the copies do not need to be deleted and a reasonable frequent restore schedule is set.
If you are using a SSD then once data is deleted and de-registered (shadow copy mechanic does not de-register, purely hides for later de-register) it is gone for good. This is because the controller has to clear freed blocks so that they can be re-used at a later time which usually occurs passively in the background (as the process is slow, not something you want to do while writing as well). Apparently advanced forensic institutes can still recover data for a few write cycles due to how the charges diffuse however this is a destructive process and very expensive.
Quote from: DrSuperGood on July 25, 2015, 12:30:33 AM
That entirely depends on the backing storage and the OS. Windows starting with Vista can use shadow copies to keep copies of modified files such that you can roll the changes back. This will always work on drives it is enabled on as long as there is sufficient free space that the copies do not need to be deleted and a reasonable frequent restore schedule is set.
That's making backups before the disaster happens. It is not on by default from what I can see.
Quote from: DrSuperGood on July 25, 2015, 12:30:33 AM
Apparently advanced forensic institutes can still recover data for a few write cycles due to how the charges diffuse however this is a destructive process and very expensive.
Such low level recovery became as good as prohibitively expensive already when normal hard drives started dynamically remapping sectors that had gone bad, so that the logical disk layout no longer matched the physical. Even if the chips containing thin information was intact, it was a lot of work to get the data, since they had to figure out how the controller worked on each drive they got. So I was told during a tour at major computer forensic and recovery company over a decade ago. Their clean rooms where they could disassemble drives to read the actual magnetic charge had not been used for quite some time.