Excluding node_modules From Backblaze Backups on Windows

I had to re-push my Backblaze backup recently because of a frozen state with a PEK, so I relooked at my setup. I realized that I was doing my exclusions all wrong.

My first rule used forward slashes like /node_modules/, which is the instinct, but Windows paths use backslashes so it never matched. Then I copied the node_modules rule from a helpful post by Kicken (aoeex.com/phile/backblaze-custom-exclusions) as-is, but it anchors to the user folder with skipFirstCharThenStartsWith=":\Users\" and my projects sit on a separate drive, so it matched nothing either.

Environment

I work mainly on my Windows desktop, mostly not WSL, which is why every path uses backslashes. My stack is mostly SvelteKit with Node and pnpm, plus Go.

The rules that worked

I ended up with two versions of this, a conservative one I started with and a broader one I’m on now. Both share the same base. These four match the folder name on any drive with skipFirstCharThenStartsWith="*", which is what I want since my projects are scattered across drives.

<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1=".git" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1=".svelte-kit" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1="\node_modules" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1=".pnpm-store" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />

Conservative: name each cache

This was my first working set. On top of the base I named each build cache I knew about, one rule per folder. The Go module cache sits under my user profile, so it keeps the :\Users\ anchor.

<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1="go-build" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith="*" contains_1="gopls" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith=":Users" contains_1="gopkgmod" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />

Broader: exclude AppData\Local

The version I’m on now. Instead of naming every cache under AppData\Local, I exclude the whole folder and list the few things I want to keep in doesNotContain, pipe separated. That catches go-build and gopls without me having to know their names. The Go module cache still needs its own rule since it lives under the profile but outside AppData.

<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith=":Users" contains_1="AppDataLocal" contains_2="*" doesNotContain="Bookmarks|WindowsTerminal|MicrosoftStickyNotes|KeePass" endsWith="*" hasFileExtension="*" />
<excludefname_rule plat="win" osVers="*" ruleIsOptional="t" skipFirstCharThenStartsWith=":Users" contains_1="gopkgmod" contains_2="*" doesNotContain="*" endsWith="*" hasFileExtension="*" />

For me the carve-outs are browser bookmarks, Windows Terminal, sticky notes, and KeePass. Everything else under AppData\Local is cache I can rebuild. The trade-off is that this rule is broad, so the doesNotContain list is the only thing standing between me and dropping something I wanted. I went this way because I was tired of finding new cache folders one at a time.

Whichever set you pick, the rules go into:

C:ProgramDataBackblazezdatazexcluderules_editable.xml

Checking it actually worked

Backblaze’s “Producing file lists” step is where it applies your exclusions to build the to-do list, so bz_todo_* under C:\ProgramData\Backblaze\bzdata\bzbackup\bzdatacenter is the result of your rules, and bz_done_* is what’s already been sent. Search the latest bz_todo for a folder you excluded, and if it’s gone, the rule took. Don’t be like me and assume it did.

Brian from Backblaze explains the file-list step in this r/backblaze thread.

Writing this down because I’ll set Backblaze up again on another machine at some point and I don’t want to relearn the backslash and :\Users\ lessons a third time. If your projects don’t sit under C:\Users, drop the anchor and match the folder name on its own.