Online RootFS growth
On growth-enabled images, Sandbox0 automatically expands the writable RootFS as free space runs low, within a configured sparse logical ceiling up to 64 TiB. Agent processes keep running. Growth is enabled in the qualified Cloud region; confirm activation for other regions. Existing images and snapshots retain their captured storage geometry. The ceiling is logical capacity, not preallocated host disk.
Zo explicitly retains files, snapshots the user filesystem and supports export. The reviewed material does not establish automatic online expansion of the complete Linux RootFS. Sandbox0 makes that growth and system-tool retention part of its runtime contract on enabled templates.