From 2cb7e0aaedad73b076ea18c6900b0e86c5760d79 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 15:00:47 +0200 Subject: Adding upstream version 247.3. Signed-off-by: Daniel Baumann --- man/systemd-pstore.service.xml | 117 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 man/systemd-pstore.service.xml (limited to 'man/systemd-pstore.service.xml') diff --git a/man/systemd-pstore.service.xml b/man/systemd-pstore.service.xml new file mode 100644 index 0000000..306f109 --- /dev/null +++ b/man/systemd-pstore.service.xml @@ -0,0 +1,117 @@ + + + + + + + + systemd-pstore.service + systemd + + + + systemd-pstore.service + 8 + + + + systemd-pstore.service + systemd-pstore + A service to archive contents of pstore + + + + /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.conf5. + + + + Disabling pstore processing + + To disable pstore processing by systemd-pstore, + set Storage=none in + pstore.conf5. + + + + + 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.d5 + mechanism, specifically the file /usr/lib/tmpfiles/systemd-pstore.conf. + + + + + + + Usage + Data stored in the journal can be viewed with + journalctl1 + as usual. + + + + See Also + + pstore.conf5 + + + -- cgit v1.2.3