Memory card offload on set: two copies and checksum verification

MultiSyncer Studio article · 3 min read

A card can go back for formatting once there are two copies on different drives and each one is checked against the card by checksum. Simply dragging files in Finder or Explorer does not check the copy against the card. MultiSyncer Studio copies a card to several drives at once, checks every copy and tells you which card is already safe to format.

How a verified offload differs from dragging files

TaskDragging in Finder or ExplorerMultiSyncer Studio
Copy checked against the cardNo: a file can be copied with an error and still look fine.Every copy is checked against the card by checksum: xxHash64, xxh3, xxh128, MD5 or SHA-1.
List of checksumsNo.Next to every verified copy there is a list of files with checksums (ASC MHL v2 and MHL 1.1).
Several drivesOne after another, by hand.To 1–4 drives at once; cascading copy: card → first drive → from it to the others, so the card can come out sooner.
Several cardsSeveral copy windows, each watched separately.Cards from different readers are copied at once; you can see when a card is free and when all copies will be ready.
A card pulled out mid-copyIt is unclear what got copied.Only that card stops; insert it again and the app finishes the copy: same number, camera and folder.
Is it safe to formatDecided by eye.“Safe to format” appears only with two verified copies on different drives; a cloud folder does not count as a copy.

How to offload cards with verification in MultiSyncer Studio

1

Fill in the project setup

Before the shoot: cameras and recorders, drives for the copies, the checksum, folders and file names in the copies. The files on the card do not change.

2

Insert the card

The app recognises the camera by its files and copies the card to every selected drive. You can insert several cards at once. Offload progress is also shown on a phone by QR code, on the same Wi-Fi.

3

Wait for the check

Every copy is checked against the card, and a list of checksums (MHL) is placed next to it. On a mismatch the app reads and copies again; no half-read files are left behind. When there are two verified copies on different drives, the card shows “Safe to format”.

4

Wrap the day

In the evening, “Wrap the day”: the day report, an edit project on every copy drive and a handover note for the editor. In the report every file has its checksum and copies.

Copying 0% 2 cards at once

The cards are free in 4 min · all copies in 9 min

AA003 · Sony FX6 · A · wide

  1. To RAID Studio
  2. Check
  3. To Backup SSD
  4. Picture, sound

SS002 · Sound Devices 888 · Sound

  1. To RAID Studio
  2. Check
  3. To Backup SSD
  4. Sound

RAID Studio · copy 1   Backup SSD · copy 2   xxh128 + ASC MHL

More: card offload in MultiSyncer Studio →

FAQ

How do I offload a card to two drives at once?

Choose the drives for the copies in the project setup and insert the card: the app copies it to every selected drive, from one to four, and checks every copy against the card by checksum.

How does checksum verification work during the copy?

The checksum is chosen in the project setup: xxHash64, xxh3, xxh128, MD5 or SHA-1. Every copy is checked against the card. Next to every verified copy there is a list of files with checksums (ASC MHL v2 and MHL 1.1). The app shows “Safe to format” only with two verified copies on different drives.

Does the app format cards itself?

No, never. It only shows which cards are already safe to format: that takes two verified copies on different drives. One copy, or a copy in a cloud folder, does not count. Cards that are not yet safe to format are marked in red.

What if a card was pulled out during the copy?

Only that card stops. Insert it again and press “Finish copying”: same number, camera and folder, and the files are checked by checksum.

Try it on your next shoot

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