engine: optimize copies to use hardlinks when possible#11497
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sipsma merged 4 commits intodagger:mainfrom Dec 2, 2025
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engine: optimize copies to use hardlinks when possible#11497sipsma merged 4 commits intodagger:mainfrom
sipsma merged 4 commits intodagger:mainfrom
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Signed-off-by: Erik Sipsma <erik@sipsma.dev>
Signed-off-by: Erik Sipsma <erik@sipsma.dev>
Signed-off-by: Erik Sipsma <erik@sipsma.dev>
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| } | ||
| // TODO: is this robust? the one for submounts is very complicated | ||
| if state.rootMount.Selector != "" { | ||
| for i, mnt := range rootMnts { |
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this for loop disappeared in the new version. Not exactly sure what it was trying to do and if you removed it deliberately.
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Yeah the loop is gone because it was unnecessary. We can just mount the rootfs and then tell runc to use a subdir of that mount rather than reset the source of each mount (which is now handled above on line 405)
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looks cool! nice speedup!
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* engine: optimize copies to use hardlinks when possible Signed-off-by: Erik Sipsma <erik@sipsma.dev> * cleanup TODOs Signed-off-by: Erik Sipsma <erik@sipsma.dev> * add integ tests Signed-off-by: Erik Sipsma <erik@sipsma.dev> * changelog Signed-off-by: Erik Sipsma <erik@sipsma.dev> --------- Signed-off-by: Erik Sipsma <erik@sipsma.dev>
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* engine: optimize copies to use hardlinks when possible Signed-off-by: Erik Sipsma <erik@sipsma.dev> * cleanup TODOs Signed-off-by: Erik Sipsma <erik@sipsma.dev> * add integ tests Signed-off-by: Erik Sipsma <erik@sipsma.dev> * changelog Signed-off-by: Erik Sipsma <erik@sipsma.dev> --------- Signed-off-by: Erik Sipsma <erik@sipsma.dev>
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Commit 52cd3ce from PR dagger#11497 regressed cross compilation. This commit fixes it. Signed-off-by: Tibor Vass <teabee89@gmail.com>
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Commit 52cd3ce from PR dagger#11497 regressed cross compilation. This commit fixes it. Signed-off-by: Tibor Vass <teabee89@gmail.com>
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Realized while talking to a user about disk usage problems that thanks to various forward progress on the Theseus front this has become some very low-hanging fruit for optimization.
Before this a
WithDirectoryoperation could under very specific circumstances useMergeOp, which attempts to use hardlinks in its implementation in order to skip copies of files and thus save disk space and time.This change greatly expands the circumstances in which that hardlink optimization is possible. It will essentially always be used now except for the cases where an owner/permission or other metadata is being modified during the copy.
Results so far:
engine-dev container sync) consumes 1.7GB less spaceTestModulestakes 2.1GB less space