DevOps

Overview The error "Too many open files" (EMFILE) occurs when a process exceeds its file descriptor (FD) limit. In Docker environments, you may hit limits at: Kernel global file table (fs.file-max) Docker daemon (dockerd)......

Why this happens Docker consumes disk via images, layers, containers, volumes, build cache, and logs. When any of these or filesystem inodes are exhausted, operations fail with: no space left on device. Quickstart (safe defaults) Run these......

What Docker healthchecks do A Docker healthcheck runs a command in the container to report if the service is working. If the command exits 0, the container is healthy; non‑zero marks it unhealthy. Orchestrators and docker compose can gate......

What these exit codes mean 139 = process crashed with SIGSEGV (segmentation fault) 143 = process terminated by SIGTERM (often during stop) 1 = process returned non-zero (generic application error) Note: 137 is SIGKILL (OOM or force......

Overview Exit code 137 means your container was terminated by SIGKILL, most commonly due to the kernel OOM killer. In Docker terms, the container hit a memory limit (or the host ran out of memory) and was OOMKilled. This guide shows how to......

Why containers exit immediately In Docker, the container stops when its PID 1 process exits. If your container exits right after docker run -d ..., it usually means: The command finished successfully and returned (normal for batch......

Overview If you see: "Error response from daemon: Container is restarting, wait until the container is running" when running docker exec, the container’s main process keeps crashing and Docker’s restart policy is bringing it back......

Overview The Docker "exec format error" typically means the kernel can’t execute a file inside the container. Two common causes: Architecture mismatch (e.g., running an amd64 binary on an arm64 host without emulation) Script......

Overview This Git error appears when you run git clone into a path that already exists and contains files: fatal: destination path 'X' already exists and is not an empty directory Git refuses to overwrite existing files during clone to......

Overview When git stash apply or git stash pop reports conflicts, Git tried to merge stashed changes into your working tree and found overlaps. The stash is safe: pop drops the stash only if the apply succeeds cleanly. You can recover,......

Overview This error typically appears when the branch’s reflog file is missing or corrupted: Message: fatal: your current branch appears to be broken Common trigger: running git reflog or commands that consult the reflog Root cause:......

What this error means You see: fatal: The following paths have staged content different from both the file and the HEAD It occurs when the index (staged version) of a path does not match either: the working tree file, and the version in......