Hvad er BACKUP1-filformatet?
En .backup1 fil er den anden del af en opdelt sikkerhedskopi lavet af en Android-enheds stock System Recovery Mode, oftest set på ældre Samsung-telefoner og tablets. Når enheden sikkerhedskopierer sin userdata-partition, er SD-kortet, der gemmer kopien, normalt formateret som FAT32, hvilket ikke kan gemme filer større end ca. 2 GB. Recovery-tilstanden omgår dette ved at skrive imaget i 2 GB-stykker: den første hedder .backup, den næste .backup1, derefter .backup2 og så videre. Hver fil bærer et tidsstempel, for eksempel userdata_20240101_000617.backup1.
På egen hånd er en .backup1-del ufuldstændig. Sammen danner delene ét image af userdata-partitionen, som indeholder kontakter, app-data, medier og indstillinger. Hvert 2 GB-stykke begynder med en 512-byte header-blok, der ikke er en del af selve dataene. Når headerne er fjernet, og delene er samlet i rækkefølge, er resultatet normalt et råt ext4-filsystem, selvom nogle enheder i stedet gemmer en gzip-komprimeret tar-strøm. På trods af det lignende navn er dette ikke .ab-formatet, der produceres af adb backup.
Sikkerhed og tryghed
RISIKO: LOWA .backup1 part is inert data, not executable, so it cannot run on its own. The main practical risk is data loss during reassembly: extract with read-only mounts and work on copies, since a missing or out-of-order part yields a corrupt ext4 image. The backup is unencrypted, so treat it as sensitive personal data because it can contain contacts, messages, and app credentials.
Formatdetaljer
kort fortalt- Generic incremental backup part - Some backup utilities append .backup1, .backup2 as generation or rotation numbers to any file's backup copy, unrelated to Android.
- Editor/app numbered backup copy - A few programs write .backup1 as a second-newest safety copy alongside .backup when saving a document or config.
Programmer der åbner BACKUP1-filer
Windows2 apps
7-Zip
Open-source For the gzip-tar variant, once the 512-byte header is removed, 7-Zip can open the resulting gzip and tar layers to extract the archived files. 
DiskInternals Linux Reader
Freemium After you concatenate the header-stripped parts into a single ext4 image, open that image in Linux Reader to browse and export files from the ext4 filesystem on Windows. 
Linux3 apps
dd + mount (coreutils / util-linux)
Open-source Strip the 512-byte header from each part with dd (skip=512), append the parts in order into one img.ext4, then mount it read-only as ext4 with mount -t ext4 -o loop,ro to browse the userdata contents.
gunzip + tar (GNU tar)
Open-source For the gzip-tar variant, pipe the header-stripped stream through gunzip and tar (dd if=userdata_....backup skip=1 bs=512 | gunzip -c | tar xv) to unpack files directly without mounting.
e2fsprogs (debugfs / dumpe2fs)
Open-source After reassembling the ext4 image, use debugfs to inspect and extract individual files or run fsck.ext4 to repair a damaged image before mounting. Tekniske detaljer
dyb specifikation| Encoding | Binary. Raw ext4 filesystem bytes, or a gzip-compressed tar stream, depending on the device recovery implementation. |
| Byte order | Little-endian (ext4 on ARM Android devices) |
| Container | Split segment: one slice of a larger logical image spread across .backup, .backup1, .backup2 and so on. |
| Compression | None for the raw-ext4 variant; gzip (DEFLATE) for the tar-based variant seen on some devices. |
| Encryption | None by default. The stock recovery backup is unencrypted, which is what makes offline extraction with dd/mount possible. |
| Typical size | About 2 GB per part; the recovery splits at the ~2GB boundary imposed by FAT32 SD cards. |
| Structure | Each part begins with a 512-byte header block that must be stripped, then holds a 2GB slice of the payload. Parts are numbered .backup (first), .backup1 (second), .backup2 (third) and continue sequentially. Concatenating the header-stripped payloads reconstructs a single ext4 image (or a single gzip+tar stream). |
| Integrity | No standard embedded checksum documented; integrity depends on all parts being present and concatenated in order. |
| Platforms | Android |
| Notes | Files carry a timestamped name such as userdata_yyyymmdd_HHMMSS.backup1 and are written to the device SD card by System Recovery Mode. This is distinct from the adb backup .ab (Android Backup) format. Reassembly command pattern: dd if=userdata_....backup1 skip=512 bs=128k iflag=skip_bytes oflag=append conv=notrunc of=img.ext4 (repeated per part), then mount -t ext4 -o loop img.ext4 /mnt. |
| Structure Type | Split multi-part image |
| Udgivet | Early 2010s (Android device recovery backups) |
BACKUP1-konverteringer
Fællesskabets Q&A
spurgt af brugereIngen spørgsmål endnu - vær den første til at spørge om BACKUP1-filer.
Ofte stillede spørgsmål
Kan jeg åbne en .backup1 fil for sig selv?
.backup1 fil er kun det andet stykke af et større image. Du skal bruge den matchende .backup første del og eventuelle yderligere .backup2, .backup3 dele, alle fra den samme sikkerhedskopi, før du kan samle og læse noget.Hvordan gendanner jeg en .backup1 sikkerhedskopi til min telefon?
Hvorfor er min sikkerhedskopi opdelt i .backup, .backup1 og .backup2 filer?
Hvordan udtrækker jeg dataene på en Windows-pc?
Er en .backup1 fil krypteret?
Er dette det samme som en adb backup .ab fil?
.ab Android Backup-formatet kommer fra kommandoen adb backup og gemmer data per app. En .backup1-del er et stykke af et råt userdata-partitionsimage lavet af enhedens recovery. De er ikke udskiftelige.
