Logrotate

設定

デフォルト

logrotate-3.7.4-8 (CentOS 5.2) の /etc/logrotate.conf の内容は以下。

weekly
rotate 4
create
#compress
include /etc/logrotate.d

動作

copytruncate

以下の設定の場合。

rotate 4
copytruncate

strace を取ってみると、過去ログを rename した後に、 open して read/write によるコピー、その後 ftruncate。

rename("/root/stap/test.log.4", "/root/stap/test.log.5") = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log.3", "/root/stap/test.log.4") = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log.2", "/root/stap/test.log.3") = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log.1", "/root/stap/test.log.2") = 0
rename("/root/stap/test.log.0", "/root/stap/test.log.1") = -1 ENOENT (No such file or directory)
access("/root/stap/test.log.5", F_OK)   = -1 ENOENT (No such file or directory)
open("/root/stap/test.log", O_RDWR|O_LARGEFILE) = 3
open("/root/stap/test.log.1", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0100644) = 4
fchmod(4, 0600)                         = 0
fchown32(4, 0, 0)                       = 0
fchmod(4, 0100644)                      = 0
read(3, "1308784634\n1308784635\n1308784636"..., 8192) = 319
write(4, "1308784634\n1308784635\n1308784636"..., 319) = 319
read(3, "", 8192)                       = 0
ftruncate64(3, 0)                       = 0
close(3)                                = 0
close(4)                                = 0

nocopytruncate

要するにデフォルトの動作。単に rename するだけ。

rename("/root/stap/test.log.4", "/root/stap/test.log.5") = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log.3", "/root/stap/test.log.4") = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log.2", "/root/stap/test.log.3") = 0
rename("/root/stap/test.log.1", "/root/stap/test.log.2") = 0
rename("/root/stap/test.log.0", "/root/stap/test.log.1") = -1 ENOENT (No such file or directory)
access("/root/stap/test.log.5", F_OK)   = -1 ENOENT (No such file or directory)
rename("/root/stap/test.log", "/root/stap/test.log.1") = 0