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SYSTEMD-PSTORE.SERVICE(8)   systemd-pstore.service   SYSTEMD-PSTORE.SERVICE(8)
NAME
       systemd-pstore.service, systemd-pstore - A service to archive contents
       of pstore
SYNOPSIS
       /usr/lib/systemd/systemd-pstore
       systemd-pstore.service
DESCRIPTION
       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 stuffs the tail of the dmesg, 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 (eg. 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.
CONFIGURATION
       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).
   Controlling 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 crash_kexec_post_notifiers parameter enables the
       kernel to write dmesg (including stack trace) into pstore upon a panic
       or crash, and printk.always_kmsg_dump parameter enables the kernel to
       write dmesg upon a normal shutdown (shutdown, reboot, halt). These
       kernel parameters are managed via the tmpfiles.d(5) mechanism,
       specifically the file /usr/lib/tmpfiles/systemd-pstore.conf.
USAGE
       Data stored in the journal can be viewed with journalctl(1) as usual.
SEE ALSO
       pstore.conf(5)
systemd 239                                          SYSTEMD-PSTORE.SERVICE(8)