1Where: /dev/pstore/... 2Date: March 2011 3Kernel Version: 2.6.39 4Contact: tony.luck@intel.com 5Description: Generic interface to platform dependent persistent storage. 6 7 Platforms that provide a mechanism to preserve some data 8 across system reboots can register with this driver to 9 provide a generic interface to show records captured in 10 the dying moments. In the case of a panic the last part 11 of the console log is captured, but other interesting 12 data can also be saved. 13 14 # mount -t pstore -o kmsg_bytes=8000 - /dev/pstore 15 16 $ ls -l /dev/pstore 17 total 0 18 -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1 19 20 Different users of this interface will result in different 21 filename prefixes. Currently two are defined: 22 23 "dmesg" - saved console log 24 "mce" - architecture dependent data from fatal h/w error 25 26 Once the information in a file has been read, removing 27 the file will signal to the underlying persistent storage 28 device that it can reclaim the space for later re-use. 29 30 $ rm /dev/pstore/dmesg-erst-1 31 32 The expectation is that all files in /dev/pstore 33 will be saved elsewhere and erased from persistent store 34 soon after boot to free up space ready for the next 35 catastrophe. 36 37 The 'kmsg_bytes' mount option changes the target amount of 38 data saved on each oops/panic. Pstore saves (possibly 39 multiple) files based on the record size of the underlying 40 persistent storage until at least this amount is reached. 41 Default is 10 Kbytes. 42