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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION | USAGE | SEE ALSO | COLOPHON |
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SYSTEMD-P...E.SERVICE(8) systemd-pstore.service SYSTEMD-P...E.SERVICE(8)
systemd-pstore.service, systemd-pstore - A service to archive
contents of pstore
/usr/lib/systemd/systemd-pstore
systemd-pstore.service
systemd-pstore.service is a system service that archives the
contents of the Linux persistent storage filesystem, pstore, to
other storage, thus preserving the existing information contained
in the pstore, and clearing pstore storage for future error
events.
Linux provides a persistent storage file system, pstore, that can
store error records when the kernel dies (or reboots or
powers-off). These records in turn can be referenced to debug
kernel problems (currently the kernel stores the tail of the
kernel log, which also contains a stack backtrace, into pstore).
The pstore file system supports a variety of backends that map
onto persistent storage, such as the ACPI ERST and UEFI
variables. The pstore backends typically offer a relatively small
amount of persistent storage, e.g. 64KiB, which can quickly fill
up and thus prevent subsequent kernel crashes from recording
errors. Thus there is a need to monitor and extract the pstore
contents so that future kernel problems can also record
information in the pstore.
The pstore service is independent of the kdump service. In cloud
environments specifically, host and guest filesystems are on
remote filesystems (e.g. iSCSI or NFS), thus kdump relies
(implicitly and/or explicitly) upon proper operation of
networking software *and* hardware *and* infrastructure. Thus it
may not be possible to capture a kernel coredump to a file since
writes over the network may not be possible.
The pstore backend, on the other hand, is completely local and
provides a path to store error records which will survive a
reboot and aid in post-mortem debugging.
The systemd-pstore executable does the actual work. Upon
starting, the pstore.conf file is read and the /sys/fs/pstore/
directory contents are processed according to the options. Pstore
files are written to the journal, and optionally saved into
/var/lib/systemd/pstore/.
The behavior of systemd-pstore is configured through the
configuration file /etc/systemd/pstore.conf and corresponding
snippets /etc/systemd/pstore.conf.d/*.conf, see pstore.conf(5).
Disabling pstore processing
To disable pstore processing by systemd-pstore, set
Storage=none
in pstore.conf(5).
Kernel parameters
The kernel has two parameters,
/sys/module/kernel/parameters/crash_kexec_post_notifiers and
/sys/module/printk/parameters/always_kmsg_dump, that control
writes into pstore. The first enables storing of the kernel log
(including stack trace) into pstore upon a panic or crash, and
the second enables storing of the kernel log upon a normal
shutdown (shutdown, reboot, halt). These parameters can be
managed via the tmpfiles.d(5) mechanism, specifically the file
/usr/lib/tmpfiles/systemd-pstore.conf.
Data stored in the journal can be viewed with journalctl(1) as
usual.
pstore.conf(5)
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 257~devel SYSTEMD-P...E.SERVICE(8)
Pages that refer to this page: pstore.conf(5), systemd.directives(7), systemd.index(7)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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