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Diffstat (limited to 'image-builder/fstab.example')
| -rw-r--r-- | image-builder/fstab.example | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/image-builder/fstab.example b/image-builder/fstab.example new file mode 100644 index 0000000..79c9473 --- /dev/null +++ b/image-builder/fstab.example @@ -0,0 +1,45 @@ +# sbo-testbuild storage layout, /etc/fstab on the docker host. +# +# Copyright (C) 2026 Danilo M. <danix@danix.xyz> +# GPLv2 only; see LICENSE. +# +# Reference copy of the two entries this build system depends on. Nothing +# reads this file; it is recorded so the layout survives a lost VM, because +# where these live is not a detail. Getting it wrong is what broke the +# nightly builds for ten days. +# +# The UUID below is this host's; use your own (`blkid /dev/sdb1`). + +# --------------------------------------------------------------------------- +# Docker data: its own disk +# --------------------------------------------------------------------------- +# Build scratch space wants room to breathe. Exporting the -current full image +# writes roughly its own size (~33G) transiently, on top of the images already +# resident, so this volume is sized for the peak and not the steady state. +# Everything on it is reproducible from the mirror, so it is excluded from +# vzdump. +UUID=0e5d008d-0ee0-41bc-9222-aedba1e088d0 /var/lib/docker ext4 defaults 0 2 + +# --------------------------------------------------------------------------- +# Registry store: NOT on the docker disk +# --------------------------------------------------------------------------- +# The registry's blob store used to be a bind mount from the docker disk +# (/var/lib/docker/registry-data). That put ~25G of permanently-resident data +# on the same volume as the transient build peak, and the two competed: the +# registry grows with every push, the build needs headroom at 03:20, and the +# build lost. Moved to the system disk on 2026-09-22, which had 49G idle. +# +# Keep them separate. The registry is small, static and I/O-light; the build +# disk is large, churning and latency-insensitive. Sharing one volume couples +# a slow leak to a hard failure. +# +# If this host's backups cover the system disk, exclude /opt/registry-data: +# the contents are reproducible by re-pushing the images. +# +# Moving it is not just an fstab edit. dockerd caches the mount in its own +# namespace, so after remounting you must restart the daemon and recreate the +# registry container, or pushes keep silently landing on the old disk. Verify +# with: grep ' /var/lib/registry ' /proc/$(docker inspect registry \ +# --format '{{.State.Pid}}')/mountinfo +# and check the device is the system disk, not the docker one. +/opt/registry-data /opt/sbo-testbuild/registry none bind 0 0 |