Recovering lost commits with reflog in Git - Step-by-Step Execution

Process Flow - Recovering lost commits with reflog

Make commits

↓

Commit lost or detached

↓

Run git reflog

↓

Find lost commit hash

↓

Use git checkout or git reset to recover

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Lost commit restored

This flow shows how git records all HEAD moves in reflog, allowing you to find and recover lost commits by checking the reflog and resetting or checking out the commit.

Execution Sample

Git

git reflog
# shows recent HEAD changes

git reset --hard <commit-hash>
# recovers lost commit by resetting HEAD

This code lists recent HEAD changes and resets the branch to a lost commit using its hash.

Process Table

Step	Command	Action	Result	Notes
1	git commit -m 'Initial commit'	Create commit	Commit abc123 created	Commit saved in branch and reflog
2	git commit -m 'Second commit'	Create commit	Commit def456 created	Commit saved in branch and reflog
3	git reset --hard abc123	Move HEAD back	HEAD now at abc123	Second commit lost from branch but in reflog
4	git reflog	Show HEAD history	Shows abc123 and def456 entries	Lost commit def456 visible here
5	git reset --hard def456	Recover lost commit	HEAD now at def456	Lost commit restored to branch
6	git reflog	Show HEAD history	Shows current HEAD at def456	Recovery complete

💡 Lost commit recovered by resetting HEAD to commit hash found in reflog

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 5	Final
HEAD	none	abc123	def456	abc123	def456	def456
Branch pointer	none	abc123	def456	abc123	def456	def456
Reflog entries	empty	abc123	abc123, def456	abc123, def456	abc123, def456	abc123, def456

Key Moments - 3 Insights

Why does the lost commit still appear in reflog after a hard reset?

Because reflog records all HEAD movements, including resets, so the lost commit hash remains accessible even if it's no longer on a branch (see Step 4 in execution_table).

Can I recover a commit if I don't know its hash?

Yes, by running 'git reflog' you can see recent commit hashes and find the lost commit hash to recover it (see Step 4).

What happens if I reset to a commit not in reflog?

Git will succeed if the commit hash is valid and exists in the repository; reflog only helps locate recent lost commits, but reset works with any valid commit hash.

Visual Quiz - 3 Questions

Look at the execution table, what is the HEAD value after Step 3?

A def456

B abc123

C none

D xyz789

💡 Hint

Check the 'HEAD' row in variable_tracker after Step 3

At which step does the lost commit get restored to the branch?

A Step 2

B Step 3

C Step 5

D Step 6

💡 Hint

Look for the 'Recover lost commit' action in execution_table

If you skip running 'git reflog', what would happen when trying to recover a lost commit?

A You won't know the commit hash to reset to

B Git automatically recovers lost commits

C You can still recover without the hash

D The lost commit is deleted permanently

💡 Hint

Refer to key_moments about finding commit hashes using reflog

Concept Snapshot

git reflog records all HEAD moves including resets
Use 'git reflog' to find lost commit hashes
Recover lost commits with 'git reset --hard <commit-hash>'
Reflog helps undo mistakes like hard resets
Lost commits remain accessible until reflog expires

Full Transcript

This lesson shows how git reflog tracks all changes to HEAD, including commits and resets. When a commit is lost due to a hard reset, it still appears in reflog. By running 'git reflog', you can find the lost commit's hash. Then, using 'git reset --hard <commit-hash>', you can restore the lost commit to your branch. The execution table traces creating commits, resetting HEAD, viewing reflog, and recovering the lost commit. Variables like HEAD and branch pointers change accordingly. Key moments clarify why reflog keeps lost commits and how to find hashes. The quiz tests understanding of HEAD values, recovery steps, and the importance of reflog. The snapshot summarizes the commands and concepts for quick reference.