Systemd linux distros use Journald service to collect and store logs in the system. Here are a couple of tips if you have problems with the space they occupy. It is good that all systemd linux distros support it – CentOS 7, Ubuntu 16+, Fedora, OpenSuse and so on.
TIP 1) Remove the old archive logs older than 10 days with
Time based removal of old logs. It will remove the old files. This command won’t change the configuration, so it just has a temporary effect.
journalctl --vacuum-time=10d
TIP 2) Remove the old archive logs greater than 1G
Size based removal of old logs. It will reduce the size of the logs to this specified size. This command won’t change the configuration, so it just has a temporary effect.
journalctl --vacuum-size=1024M
TIP 3) Show disk usage
[root@srv ~]# journalctl --disk-usage Archived and active journals take up 785.5M on disk.
TIP 4) Show all logs and information for them
Where are the log files, the size they occupy, the time period of the entries in them and more:
[root@srv0 ~]# journalctl --header File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system.journal File ID: 7deaff4610a94c82aab85386597e825b Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ONLINE Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 1239405 Tail Sequential Number: 1341511 Head Realtime Timestamp: mon 2018-06-25 10:09:09 UTC Tail Realtime Timestamp: tue 2018-06-28 00:07:10 UTC Tail Monotonic Timestamp: 1month 2d 21h 6min 47.287s Objects: 258136 Entry Objects: 102107 Data Objects: 129585 Data Hash Table Fill: 72.5% Field Objects: 36 Field Hash Table Fill: 10.8% Tag Objects: 0 Entry Array Objects: 26406 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-000000000011512d-00056f3f3ff56172.journal File ID: a8e1f042bc144df78f37005b0b555a82 Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 1134893 Tail Sequential Number: 1239404 Head Realtime Timestamp: fri 2018-06-22 18:32:10 UTC Tail Realtime Timestamp: mon 2018-06-25 10:09:09 UTC Tail Monotonic Timestamp: 1month 7h 8min 45.991s Objects: 263445 Entry Objects: 104512 Data Objects: 131953 Data Hash Table Fill: 73.8% Field Objects: 34 Field Hash Table Fill: 10.2% Tag Objects: 0 Entry Array Objects: 26944 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-00000000000fc083-00056f0d6ef70320.journal File ID: 007272b1f181487d83116bee96c40c30 Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 1032323 Tail Sequential Number: 1134892 Head Realtime Timestamp: wed 2018-06-20 07:06:10 UTC Tail Realtime Timestamp: fri 2018-06-22 18:32:10 UTC Tail Monotonic Timestamp: 4w 2h 1min 46.980s Objects: 263998 Entry Objects: 102570 Data Objects: 133456 Data Hash Table Fill: 74.7% Field Objects: 37 Field Hash Table Fill: 11.1% Tag Objects: 0 Entry Array Objects: 27933 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-00000000000e3f67-00056ee09376d287.journal File ID: 4c268268a6e34d6297c7ae9ca01fc31b Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: yes Head Sequential Number: 933735 Tail Sequential Number: 1032322 Head Realtime Timestamp: mon 2018-06-18 01:35:09 UTC Tail Realtime Timestamp: wed 2018-06-20 07:06:10 UTC Tail Monotonic Timestamp: 3w 4d 14h 35min 47.248s Objects: 261498 Entry Objects: 98588 Data Objects: 134059 Data Hash Table Fill: 75.0% Field Objects: 40 Field Hash Table Fill: 12.0% Tag Objects: 0 Entry Array Objects: 28809 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-00000000000cbf3b-00056eb3ea255b2a.journal File ID: 7019a721bebe4e00b76410a6e7052c6d Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: yes Head Sequential Number: 835387 Tail Sequential Number: 933734 Head Realtime Timestamp: fri 2018-06-15 20:18:10 UTC Tail Realtime Timestamp: mon 2018-06-18 01:35:09 UTC Tail Monotonic Timestamp: 3w 2d 9h 4min 45.972s Objects: 260794 Entry Objects: 98348 Data Objects: 134060 Data Hash Table Fill: 75.0% Field Objects: 33 Field Hash Table Fill: 9.9% Tag Objects: 0 Entry Array Objects: 28351 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-00000000000b2fac-00056e827d3375dd.journal File ID: 61c16e8acc364d97b8c0c7cc2afcb6ec Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 733100 Tail Sequential Number: 835386 Head Realtime Timestamp: wed 2018-06-13 09:20:08 UTC Tail Realtime Timestamp: fri 2018-06-15 20:18:10 UTC Tail Monotonic Timestamp: 3w 3h 47min 46.827s Objects: 264298 Entry Objects: 102287 Data Objects: 134043 Data Hash Table Fill: 75.0% Field Objects: 33 Field Hash Table Fill: 9.9% Tag Objects: 0 Entry Array Objects: 27933 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-000000000009966a-00056e4cbbb6ebfc.journal File ID: c90df7bdc4654ab7a4ac955c74a779a3 Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 628330 Tail Sequential Number: 733099 Head Realtime Timestamp: sun 2018-06-10 17:12:09 UTC Tail Realtime Timestamp: wed 2018-06-13 09:19:10 UTC Tail Monotonic Timestamp: 2w 4d 16h 48min 46.993s Objects: 263295 Entry Objects: 104770 Data Objects: 131816 Data Hash Table Fill: 73.7% Field Objects: 37 Field Hash Table Fill: 11.1% Tag Objects: 0 Entry Array Objects: 26670 Disk usage: 98.1M File Path: /run/log/journal/bb5aa69bfa2b483386443ede7a92a45a/system@541a59d9a68342d3980d86e565a48c7d-000000000007fd20-00056e16f3135f30.journal File ID: 32915d651dd84728b9e4a33a97b480cf Machine ID: bb5aa69bfa2b483386443ede7a92a45a Boot ID: e89507fa3f814b8a96f9d70914c120b0 Sequential Number ID: 541a59d9a68342d3980d86e565a48c7d State: ARCHIVED Compatible Flags: Incompatible Flags: COMPRESSED-XZ Header size: 240 Arena size: 102956816 Data Hash Table Size: 178744 Field Hash Table Size: 333 Rotate Suggested: no Head Sequential Number: 523552 Tail Sequential Number: 628329 Head Realtime Timestamp: fri 2018-06-08 01:02:10 UTC Tail Realtime Timestamp: sun 2018-06-10 17:12:09 UTC Tail Monotonic Timestamp: 2w 2d 41min 46.200s Objects: 263287 Entry Objects: 104778 Data Objects: 131696 Data Hash Table Fill: 73.7% Field Objects: 36 Field Hash Table Fill: 10.8% Tag Objects: 0 Entry Array Objects: 26775 Disk usage: 98.1M [root@srv0 ~]#
* Deleting logs
[root@srv0 ~]# journalctl --vacuum-size=128M Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a33241-000570199db5be3c.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a34463-0005701a0b24d0fc.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3568c-0005701a79e388c7.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a36899-0005701ae529f439.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a37ac8-0005701b50781f62.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a38cde-0005701bbd3b60c3.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a39ef6-0005701c28dcf40e.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3b0f1-0005701c9416ee94.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3c309-0005701cffe19015.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3d521-0005701d6c79b9cb.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3e748-0005701dd7c60e79.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a3f92d-0005701e48413eb8.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a40b0a-0005701ec83a0c74.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a41ce2-0005701f3fdcadc6.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a42f04-0005701fabfefbca.journal (8.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a4410e-000570201757a256.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a60a8f-0005702ac025bb0c.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a7d254-000570359f2bd7eb.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000a99a34-000570405b5e812e.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000ab639b-0005704b05553c7d.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000ad2c3e-00057055cb403fae.journal (120.0M). Deleted archived journal /var/log/journal/9be717e698354ec481abb641cf4085c3/system@79d0440cc1174c2db132b707a0567bcb-0000000000aef5c8-000570607686fd78.journal (120.0M). Vacuuming done, freed 960.0M of archived journals from /var/log/journal/9be717e698354ec481abb641cf4085c3.