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Before, journald would remove journal files until both MaxUse= and KeepFree= settings would be satisfied. The first one depends (if set automatically) on the size of the file system and is constant. But the second one depends on current use of the file system, and a spike in disk usage would cause journald to delete journal files, trying to reach usage which would leave 15% of the disk free. This behaviour is surprising for the user who doesn't expect his logs to be purged when disk usage goes above 85%, which on a large disk could be some gigabytes from being full. In addition attempting to keep 15% free provides an attack vector where filling the disk sufficiently disposes of almost all logs. Instead, obey KeepFree= only as a limit on adding additional files. When replacing old files with new, ignore KeepFree=. This means that if journal disk usage reached some high point that at some later point start to violate the KeepFree= constraint, journald will not add files to go above this point, but it will stay (slightly) below it. When journald is restarted, it forgets the previous maximum usage value, and sets the limit based on the current usage, so if disk remains to be filled, journald might use one journal-file-size less on each restart, if restarts happen just after rotation. This seems like a reasonable compromise between implementation complexity and robustness. |
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catalog | ||
docs | ||
hwdb | ||
m4 | ||
man | ||
network | ||
po | ||
rules | ||
shell-completion | ||
src | ||
sysctl.d | ||
test | ||
tmpfiles.d | ||
units | ||
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.vimrc | ||
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autogen.sh | ||
CODING_STYLE | ||
configure.ac | ||
DISTRO_PORTING | ||
LICENSE.GPL2 | ||
LICENSE.LGPL2.1 | ||
LICENSE.MIT | ||
make-directive-index.py | ||
make-man-index.py | ||
make-man-rules.py | ||
Makefile-man.am | ||
Makefile.am | ||
NEWS | ||
README | ||
TODO | ||
xml_helper.py |
systemd System and Service Manager DETAILS: http://0pointer.de/blog/projects/systemd.html WEB SITE: http://www.freedesktop.org/wiki/Software/systemd GIT: git://anongit.freedesktop.org/systemd/systemd ssh://git.freedesktop.org/git/systemd/systemd GITWEB: http://cgit.freedesktop.org/systemd/systemd MAILING LIST: http://lists.freedesktop.org/mailman/listinfo/systemd-devel http://lists.freedesktop.org/mailman/listinfo/systemd-commits IRC: #systemd on irc.freenode.org BUG REPORTS: https://bugs.freedesktop.org/enter_bug.cgi?product=systemd AUTHOR: Lennart Poettering Kay Sievers ...and many others LICENSE: LGPLv2.1+ for all code - except sd-daemon.[ch] and sd-readahead.[ch] which are MIT - except src/shared/MurmurHash2.c which is Public Domain - except src/shared/siphash24.c which is CC0 Public Domain - except src/journal/lookup3.c which is Public Domain - except src/udev/* which is (currently still) GPLv2, GPLv2+ REQUIREMENTS: Linux kernel >= 3.0 CONFIG_DEVTMPFS CONFIG_CGROUPS (it's OK to disable all controllers) CONFIG_INOTIFY_USER CONFIG_SIGNALFD CONFIG_TIMERFD CONFIG_EPOLL CONFIG_NET CONFIG_SYSFS CONFIG_PROC_FS Linux kernel >= 3.8 for Smack support Udev will fail to work with the legacy layout: CONFIG_SYSFS_DEPRECATED=n Legacy hotplug slows down the system and confuses udev: CONFIG_UEVENT_HELPER_PATH="" Userspace firmware loading is deprecated, will go away, and sometimes causes problems: CONFIG_FW_LOADER_USER_HELPER=n Some udev rules and virtualization detection relies on it: CONFIG_DMIID Mount and bind mount handling might require it: CONFIG_FHANDLE Support for some SCSI devices serial number retrieval, to create additional symlinks in /dev/disk/ and /dev/tape: CONFIG_BLK_DEV_BSG Optional but strongly recommended: CONFIG_IPV6 CONFIG_AUTOFS4_FS CONFIG_TMPFS_POSIX_ACL CONFIG_TMPFS_XATTR CONFIG_SECCOMP For systemd-bootchart, several proc debug interfaces are required: CONFIG_SCHEDSTATS CONFIG_SCHED_DEBUG For UEFI systems: CONFIG_EFI_VARS CONFIG_EFI_PARTITION Note that kernel auditing is broken when used with systemd's container code. When using systemd in conjunction with containers, please make sure to either turn off auditing at runtime using the kernel command line option "audit=0", or turn it off at kernel compile time using: CONFIG_AUDIT=n glibc >= 2.14 libcap libblkid >= 2.20 (from util-linux) (optional) libkmod >= 15 (optional) PAM >= 1.1.2 (optional) libcryptsetup (optional) libaudit (optional) libacl (optional) libattr (optional) libselinux (optional) liblzma (optional) tcpwrappers (optional) libgcrypt (optional) libqrencode (optional) libmicrohttpd (optional) libpython (optional) make, gcc, and similar tools During runtime, you need the following additional dependencies: util-linux >= v2.19 (requires fsck -l, agetty -s), v2.21 required for tests in test/ dbus >= 1.4.0 (strictly speaking optional, but recommended) sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended, required for tests in test/) dracut (optional) PolicyKit (optional) When building from git, you need the following additional dependencies: docbook-xsl xsltproc automake autoconf libtool intltool gperf gtkdocize (optional) python (optional) sphinx (optional) python-lxml (entirely optional) When systemd-hostnamed is used, it is strongly recommended to install nss-myhostname to ensure that, in a world of dynamically changing hostnames, the hostname stays resolvable under all circumstances. In fact, systemd-hostnamed will warn if nss-myhostname is not installed. To build HTML documentation for python-systemd using sphinx, please first install systemd (using 'make install'), and then invoke sphinx-build with 'make sphinx-<target>', with <target> being 'html' or 'latexpdf'. If using DESTDIR for installation, pass the same DESTDIR to 'make sphinx-html' invocation. USERS AND GROUPS: Default udev rules use the following standard system group names, which need to be resolvable by getgrnam() at any time, even in the very early boot stages, where no other databases and network are available: tty, dialout, kmem, video, audio, lp, floppy, cdrom, tape, disk During runtime, the journal daemon requires the "systemd-journal" system group to exist. New journal files will be readable by this group (but not writable), which may be used to grant specific users read access. It is also recommended to grant read access to all journal files to the system groups "wheel" and "adm" with a command like the following in the post installation script of the package: # setfacl -nm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/ The journal gateway daemon requires the "systemd-journal-gateway" system user and group to exist. During execution this network facing service will drop privileges and assume this uid/gid for security reasons. WARNINGS: systemd will warn you during boot if /etc/mtab is not a symlink to /proc/mounts. Please ensure that /etc/mtab is a proper symlink. systemd will warn you during boot if /usr is on a different file system than /. While in systemd itself very little will break if /usr is on a separate partition, many of its dependencies very likely will break sooner or later in one form or another. For example, udev rules tend to refer to binaries in /usr, binaries that link to libraries in /usr or binaries that refer to data files in /usr. Since these breakages are not always directly visible, systemd will warn about this, since this kind of file system setup is not really supported anymore by the basic set of Linux OS components. For more information on this issue consult http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken To run systemd under valgrind, compile with VALGRIND defined (e.g. ./configure CPPFLAGS='... -DVALGRIND=1'). Otherwise, false positives will be triggered by code which violates some rules but is actually safe.