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1What: /sys/fs/pstore/...2What: /dev/pstore/...3Date: March 20114KernelVersion: 2.6.395Contact: tony.luck@intel.com6Description: Generic interface to platform dependent persistent storage.7 8 Platforms that provide a mechanism to preserve some data9 across system reboots can register with this driver to10 provide a generic interface to show records captured in11 the dying moments. In the case of a panic the last part12 of the console log is captured, but other interesting13 data can also be saved::14 15 # mount -t pstore -o kmsg_bytes=8000 - /sys/fs/pstore16 17 $ ls -l /sys/fs/pstore/18 total 019 -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-120 21 Different users of this interface will result in different22 filename prefixes. Currently two are defined:23 24 - "dmesg" - saved console log25 - "mce" - architecture dependent data from fatal h/w error26 27 Once the information in a file has been read, removing28 the file will signal to the underlying persistent storage29 device that it can reclaim the space for later re-use::30 31 $ rm /sys/fs/pstore/dmesg-erst-132 33 The expectation is that all files in /sys/fs/pstore/34 will be saved elsewhere and erased from persistent store35 soon after boot to free up space ready for the next36 catastrophe.37 38 The 'kmsg_bytes' mount option changes the target amount of39 data saved on each oops/panic. Pstore saves (possibly40 multiple) files based on the record size of the underlying41 persistent storage until at least this amount is reached.42 Default is 10 Kbytes.43 44 Pstore only supports one backend at a time. If multiple45 backends are available, the preferred backend may be46 set by passing the pstore.backend= argument to the kernel at47 boot time.48