Become a Site Supporter and Never see Ads again!

Author Topic: TSKB - Verifying master file transfers from original memory card  (Read 3732 times)

0 Members and 1 Guest are viewing this topic.

Offline morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 4098
  • (see snopes.com for more info)

Time Machine Maintenance Tip #TMMT202004061


Have you ever wanted to be certain that the master media files stored in your archives are identical to the files you recorded at the time of the event?
One way to verify files is to use a checksum. This operation can be performed directly on the original media file.
A couple years ago, I began to checksum the original files on the master storage medium, immediately after having transferred the master files to my Masters folder.
Because my audio master files are recorded in WAV format, I use the MD5 checksum, which is a whole-file checksum
The MD5 hash value can be calculated for a file of any format, it is not specific to media files. FFP can only be used on FLAC, and I don't have those as masters.
I direct my software (xACT for mac, Traders Little Helper for Windows) to save the .MD5 checksum file into the folder with my newly transferred master file(s)
It takes just as long to compute MD5 as it does to transfer the original file, because you are reading the card again at the same speed.
Once the file itself is copied to my computer's internal (SSD!) drive, I can create the .MD5 checksum file for my backup.
As soon as the (SLOW!) original MD5 is finished calculating, I can drag the two .MD5 files into my text editor and confirm that the results are the same.
If the checksums are the same, then you have verified that the file which transferred is the exact same as the one on the memory used in the recorder.
Once the new computer file is copied to at least two other drives, the master itself may be safely deleted from the recorder.


Your comments are totally welcome. I made a whole new thread here for this!!!


It appears, as you can see in the attached image of this year's stuff, that I only do this verification for important recordings.
I don't always checksum the masters of brief city soundscape recordings I make, like bird chirps, garbage trucks, sideshow cars, and siren tests.
PS mods, feel free to move this thread to the best place for it.

hey now!

Offline jerryfreak

  • Trade Count: (30)
  • Needs to get out more...
  • *****
  • Posts: 4329
  • high desert for life
Re: TSKB - Verifying master file transfers from original memory card
« Reply #1 on: April 06, 2020, 08:57:54 AM »
you can also make .md5 files recursively for folders or even whole drives
my facemask is a windscreen

People whose posts I wont see:
capnhook, daspyknows, Melanie, morst, Rob D., Scooter123, Sloan Simpson, Walstib62

Offline jerryfreak

  • Trade Count: (30)
  • Needs to get out more...
  • *****
  • Posts: 4329
  • high desert for life
Re: TSKB - Verifying master file transfers from original memory card
« Reply #2 on: April 12, 2020, 08:50:24 AM »
speaking of which, i forgot how to register mkw toolkit in windows to 'create md5' in the right-click context menu in a folder... this used to be a standard issue on any build for me, but im going thru some old drives and lacking this feature. so i found this which seems to do the trick

http://code.kliu.org/hashcheck/
« Last Edit: April 12, 2020, 09:02:45 AM by jerryfreak »
my facemask is a windscreen

People whose posts I wont see:
capnhook, daspyknows, Melanie, morst, Rob D., Scooter123, Sloan Simpson, Walstib62

Offline morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 4098
  • (see snopes.com for more info)
Re: TSKB - Verifying master file transfers from original memory card
« Reply #3 on: April 12, 2020, 04:09:51 PM »
you can also make .md5 files recursively for folders or even whole drives
Yes, you can, but if the file path changes later (perhaps because you move or rename a folder) then the MD5 will fail.
I find that it's most useful to keep the .MD5 (or .ffp) checksums in the exact same folder as the files they belong to.
Also doing them all at once will be very slow to create, and very slow to check.
hey now!

Offline jerryfreak

  • Trade Count: (30)
  • Needs to get out more...
  • *****
  • Posts: 4329
  • high desert for life
Re: TSKB - Verifying master file transfers from original memory card
« Reply #4 on: April 13, 2020, 02:52:26 AM »
you can also make .md5 files recursively for folders or even whole drives
Yes, you can, but if the file path changes later (perhaps because you move or rename a folder) then the MD5 will fail.
I find that it's most useful to keep the .MD5 (or .ffp) checksums in the exact same folder as the files they belong to.
Also doing them all at once will be very slow to create, and very slow to check.

its actually relative path, the .md5 just has to be in the same relative location to the files you are checking. im checking a 71000 file .md5 from a 2TB drive as i type this
my facemask is a windscreen

People whose posts I wont see:
capnhook, daspyknows, Melanie, morst, Rob D., Scooter123, Sloan Simpson, Walstib62

 

RSS | Mobile
Page created in 0.038 seconds with 47 queries.
© 2002-2020 Taperssection.com
Powered by SMF