pstore 1.7 KB

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  1. Where: /sys/fs/pstore/... (or /dev/pstore/...)
  2. Date: March 2011
  3. Kernel Version: 2.6.39
  4. Contact: tony.luck@intel.com
  5. Description: Generic interface to platform dependent persistent storage.
  6. Platforms that provide a mechanism to preserve some data
  7. across system reboots can register with this driver to
  8. provide a generic interface to show records captured in
  9. the dying moments. In the case of a panic the last part
  10. of the console log is captured, but other interesting
  11. data can also be saved.
  12. # mount -t pstore -o kmsg_bytes=8000 - /sys/fs/pstore
  13. $ ls -l /sys/fs/pstore/
  14. total 0
  15. -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1
  16. Different users of this interface will result in different
  17. filename prefixes. Currently two are defined:
  18. "dmesg" - saved console log
  19. "mce" - architecture dependent data from fatal h/w error
  20. Once the information in a file has been read, removing
  21. the file will signal to the underlying persistent storage
  22. device that it can reclaim the space for later re-use.
  23. $ rm /sys/fs/pstore/dmesg-erst-1
  24. The expectation is that all files in /sys/fs/pstore/
  25. will be saved elsewhere and erased from persistent store
  26. soon after boot to free up space ready for the next
  27. catastrophe.
  28. The 'kmsg_bytes' mount option changes the target amount of
  29. data saved on each oops/panic. Pstore saves (possibly
  30. multiple) files based on the record size of the underlying
  31. persistent storage until at least this amount is reached.
  32. Default is 10 Kbytes.
  33. Pstore only supports one backend at a time. If multiple
  34. backends are available, the preferred backend may be
  35. set by passing the pstore.backend= argument to the kernel at
  36. boot time.