我试图删除特定单元的所有日志记录，但似乎总是有 8M 的日志。为什么？
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-0000000000004401-00058ea55d54b03c.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-0000000000004402-00058ea55ef09b8b.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-0000000000004403-00058ea55f2a72e2.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-0000000000004404-00058ea55f91cd3d.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
为什么真空清洁不能删除错误消息以及如何强制它执行此操作？
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-00000000000044b1-00058ea592efa531.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
root@lian:midenok# jctl -u networking
-- Logs begin at Fri 2018-10-12 13:19:45 MSK, end at Sat 2019-07-27 11:42:55 MSK. --
Oct 12 13:19:50 lian systemd[1]: networking.service: Failed to create cgroup /system.slice/networking.ser
Oct 12 13:19:50 lian systemd[1]: Stopping Raise network interfaces...
Oct 12 13:19:50 lian systemd[1]: networking.service: Control process exited, code=exited status=219
Oct 12 13:19:50 lian systemd[1]: networking.service: Failed with result 'exit-code'.
Oct 12 13:19:50 lian systemd[1]: Stopped Raise network interfaces.
root@lian:midenok# jctl -u networking --rotate --vacuum-time=1s
Vacuuming done, freed 0B of archived journals from /var/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
Deleted archived journal /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f/system@1cd4da499faf49efbab36bcf2fcb95ec-00000000000044b2-00058ea5a52ff5a3.journal (8.0M).
Vacuuming done, freed 8.0M of archived journals from /run/log/journal/436bc0322e1ed0ccf7a95f6a536bc14f.
root@lian:midenok# jctl -u networking
-- Logs begin at Fri 2018-10-12 13:19:45 MSK, end at Sat 2019-07-27 11:43:03 MSK. --
Oct 12 13:19:50 lian systemd[1]: networking.service: Failed to create cgroup /system.slice/networking.ser
Oct 12 13:19:50 lian systemd[1]: Stopping Raise network interfaces...
Oct 12 13:19:50 lian systemd[1]: networking.service: Control process exited, code=exited status=219
Oct 12 13:19:50 lian systemd[1]: networking.service: Failed with result 'exit-code'.
Oct 12 13:19:50 lian systemd[1]: Stopped Raise network interfaces.