Public bug reported:
Suppose you have a file in hostA:
hostA$ ls -l /tmp/files
-rw-rw-r-- 2 root root 563016 Jan 10 15:01 test.txt
You download it from the hostB using:
hostB$ rsync -u --inplace --partial -a hostA::files/* .
If the transfer is aborted, hostB will get only a partial file:
hostB$ ls -l /tmp/files
-rw-rw-r-- 2 root root 2024 Jan 11 18:00 test.txt
BUT the ctime/mtime of hostB/test.txt now is NEWER than hostA/test.txt(and
mtime == ctime). So, if you run the same rsync -u command again:
hostB$ rsync -u --inplace --partial -a hostA::files/* .
Rsync will SKIP THE FILE, because hostB/test.txt is "newer" than
hostA/test.txt. So you CAN'T resume using rsync -u command, and you will
think there are no differences.
To avoid this bug, rsync must create the file with ctime=mtime=0. And if
the file already exists before transfer, rsync -u must not change his
current ctime/mtime. Ctime/mtime must be updated ONLY after the transfer
was successfully completed.
Note this is really need because there are scenarios where checksum
comparison can't be used, only comparison by time. For example, to avoid
deleting changes made in hostB to test.txt. Also I need to use
--inplace.
** Affects: rsync (Ubuntu)
Importance: Undecided
Status: New
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Touch seeded packages, which is subscribed to rsync in Ubuntu.
https://bugs.launchpad.net/bugs/1659950
Title:
rsync -u --inplace --partial -a can't resume transfer
Status in rsync package in Ubuntu:
New
Bug description:
Suppose you have a file in hostA:
hostA$ ls -l /tmp/files
-rw-rw-r-- 2 root root 563016 Jan 10 15:01 test.txt
You download it from the hostB using:
hostB$ rsync -u --inplace --partial -a hostA::files/* .
If the transfer is aborted, hostB will get only a partial file:
hostB$ ls -l /tmp/files
-rw-rw-r-- 2 root root 2024 Jan 11 18:00 test.txt
BUT the ctime/mtime of hostB/test.txt now is NEWER than hostA/test.txt(and
mtime == ctime). So, if you run the same rsync -u command again:
hostB$ rsync -u --inplace --partial -a hostA::files/* .
Rsync will SKIP THE FILE, because hostB/test.txt is "newer" than
hostA/test.txt. So you CAN'T resume using rsync -u command, and you
will think there are no differences.
To avoid this bug, rsync must create the file with ctime=mtime=0. And
if the file already exists before transfer, rsync -u must not change
his current ctime/mtime. Ctime/mtime must be updated ONLY after the
transfer was successfully completed.
Note this is really need because there are scenarios where checksum
comparison can't be used, only comparison by time. For example, to
avoid deleting changes made in hostB to test.txt. Also I need to use
--inplace.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/rsync/+bug/1659950/+subscriptions
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