Docs feedback: Clarify "enough free space" requirement for direct transfer
Problem to solve
Under Migrate groups and projects by using direct transfer > Network and storage space we vaguely require
… enough free space in the
/tmpdir…
But relative to what?
Further details
In exported_relations_merger.rb, it seems like both the compressed and unpacked project .tar.gz are present at the same time.
IIUC, this indicates that "enough free space" essentially means either
2x/2.5x/3x/?x the size of the largest source project
(if all projects pass through download_or_copy_upload & untar_zxf & File.delete(tar_gz_full_path) run sequentially) or
2x/2.5x/3x/?x the size of all source projects combined
if that procedure runs in parallel for all projects?
The multipliers are just my guesses about how effective the gz compression is in the case of Git repos + GitLab data. Maybe it needs to be higher, if the compression is better?
Proposal
Specify both a multiplier and the source data point to check, as outlined in the above quotes.