When the Symantec Management Agent (aka Altiris Agent) is downloading a package, the process can sometimes be interrupted due to many different reasons. When that happens, the agent will cache the portion of the package it has already downloaded. The agent will enter a waiting to retry download state and attempt the download again after a short period of wait time. The agent will pick up the download where it left off, using the cached portion of the downloaded files.
Note: Packages which are downloaded via Package Multicast do not utilize checkpoint recovery, i.e If a multicast package download is interrupted mid-way through, it will pick up the download from the beginning when it retries. If download is terminated, it will start from beginning, no resume for multicast.
With ITMS 8.5 release
Now it’s even better than before. We got block level downloading, so agent checks hashes of the already downloaded blocks and downloads only the missing or corrupted blocks. Each block is 2MB size by default.
The download will pick up where it left off plus it will recover any corrupted blocks if there are any. It does not work for multicast as before.
What if you unplug the network cable during a file transfer, wait a few minutes and plug the cable back in, checkpoint recovery will pick up where it left off?. If you power off your computer during a file transfer, do you lose the cache and the download will start over again from the beginning?
There is no timeout when cache is lost. All the time when agent starts after reboot or network restored after cable unplugged or undocking it will check for packages and will resume download from the last point of download where it stopped.
There is no any timeout or some separated cache files. The download is performed into the package folder and already downloaded content is the “cache” itself.
Do we keep any records in the agent secure storage (aka LDB folder) about package download progress or status?
No, the whole package progress is in Software Framework (SMF) XMLs. The hashes are in package snapshot in secure storage. The partially downloaded files are in package folder.