Julian, I can't recreate this.
I ran the above with timings on a canonistack instance. I believe that it correctly shows that simplestreams downloading is not significantly slower than wget.
Note, that maas-import-ephemerals is doing substantially more than 'wget', so its not apples to apples.
for a give ephemeral tar file, it does:
download the tar file (giving no status output, bug 1238148)
extract it to get the kernel and initramfs and .img file
copies (see bug 1239159) these files into place
mounts the .img file and creates the dist-root.tar.gz file from it (700+M of READ IO, compress, 250M of write)
Julian, I can't recreate this.
I ran the above with timings on a canonistack instance. I believe that it correctly shows that simplestreams downloading is not significantly slower than wget.
Note, that maas-import- ephemerals is doing substantially more than 'wget', so its not apples to apples.
for a give ephemeral tar file, it does:
download the tar file (giving no status output, bug 1238148)
extract it to get the kernel and initramfs and .img file
copies (see bug 1239159) these files into place
mounts the .img file and creates the dist-root.tar.gz file from it (700+M of READ IO, compress, 250M of write)
Note that the fix I put in for https:/ /launchpad. net/bugs/ 1240652 does improve downloading a bit int hat it doesn't stat unnecessarily.
If you want to compare download only times with simplestreams download code there is examples in bug 1240652 on how to do that.