Where Does Backblaze Keep Backup Data and Logs?
The Backblaze backup client keeps its working data under bzdata: daily logs in bzlogs, file lists in bzfilelists, and the untouchable bz_done records.
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Backblaze Computer Backup keeps a busy backstage folder called bzdata, and it rewards the curious while punishing the careless. The logs inside are plain text and safe to read. The bz_done files next to them are the client's memory of everything uploaded, and editing them corrupts the backup beyond repair.
You rarely need this folder for daily use. Restores happen through the web account. Come here when debugging, when support asks for logs, or when you want to confirm what the client is actually doing.
Where Backblaze stores this, by platform
C:\ProgramData\Backblaze\bzdata
bzlogs holds one log per executable per day (bztransmit16.log means the 16th), compressed after two days and deleted after 26. bzfilelists and bzbackup\bzdatacenter hold the client's state. Read freely, but never edit the bz_done files.
/Library/Backblaze.bzpkg/bzdata
Same layout as Windows: bzlogs for readable logs, bzbackup for state. Reach it with Finder Go to Folder. Support's Mac permission-fix procedure targets this exact folder when the client cannot write to it.
Frequently asked questions
Where do I look when a backup seems stuck?
Open the bztransmit logs in bzdata\bzlogs and search for ERROR in capitals. One or two errors (a dropped connection, a sleeping drive) are normal. Hundreds of identical errors point at the real problem.
Can I clean up the bz_done files to save space?
Never. The bz_done files are an append-only record of everything uploaded, and changing a single byte corrupts the backup state. Copy one elsewhere and inspect the copy if you are curious.
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