From 1abe0a8f34fcda19f0939c26be9b60cd734e671f Mon Sep 17 00:00:00 2001 From: Grzegorz Szczepanczyk Date: Fri, 19 Jun 2026 10:34:15 +0200 Subject: [PATCH] docs: clarify partial vs lazy image pulling The performance tutorial calls Podman's zstd:chunked / eStargz support "lazy pulling", which isn't accurate. By itself Podman only does partial pulling: it skips layer content it already has, but the image is still fully pulled before a container runs. Real lazy pulling, where the image is mounted before the download finishes, needs an external snapshotter such as stargz-snapshotter. Rename the section to "partial pulling" and add a sentence spelling out the difference, as @giuseppe suggested on the issue. Fixes: #24947 Signed-off-by: Grzegorz Szczepanczyk --- docs/tutorials/performance.md | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/docs/tutorials/performance.md b/docs/tutorials/performance.md index f2c1730310..8295f611e4 100644 --- a/docs/tutorials/performance.md +++ b/docs/tutorials/performance.md @@ -180,9 +180,9 @@ $ podman info -f '{{.Host.RootlessNetworkCmd}}' pasta ``` -### Lazy pulling of container images +### Partial pulling of container images -Podman supports lazy pulling for the following container image formats: +Podman supports partial pulling for the following container image formats: * __zstd:chunked__ @@ -190,11 +190,13 @@ Podman supports lazy pulling for the following container image formats: __zstd:chunked__ has better performance than __eStargz__. +Partial pulling downloads only the layer contents that are missing locally, but the image is still fully pulled before its containers run. Lazy pulling, where the image is mounted before it is fully downloaded, is out of scope for Podman itself and requires an additional snapshotter such as the [stargz-snapshotter](https://github.com/containerd/stargz-snapshotter) configured as an additional layer store. + See the article [_Pull container images faster with partial pulls_](https://www.redhat.com/sysadmin/faster-container-image-pulls) by Giuseppe Scrivano and Dan Walsh. ### Choosing a host file system -Lazy pulling of container images can run more efficiently when the file system has reflink support. The file systems XFS and BTRFS have reflink support. +Partial pulling of container images can run more efficiently when the file system has reflink support. The file systems XFS and BTRFS have reflink support. ### Option --log-driver