1What:		/sys/fs/pstore/...
2What:		/dev/pstore/...
3Date:		March 2011
4KernelVersion: 2.6.39
5Contact:	tony.luck@intel.com
6Description:	Generic interface to platform dependent persistent storage.
7
8		Platforms that provide a mechanism to preserve some data
9		across system reboots can register with this driver to
10		provide a generic interface to show records captured in
11		the dying moments.  In the case of a panic the last part
12		of the console log is captured, but other interesting
13		data can also be saved::
14
15		    # mount -t pstore -o kmsg_bytes=8000 - /sys/fs/pstore
16
17		    $ ls -l /sys/fs/pstore/
18		    total 0
19		    -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1
20
21		Different users of this interface will result in different
22		filename prefixes.  Currently two are defined:
23
24		- "dmesg" - saved console log
25		- "mce"   - architecture dependent data from fatal h/w error
26
27		Once the information in a file has been read, removing
28		the file will signal to the underlying persistent storage
29		device that it can reclaim the space for later re-use::
30
31		    $ rm /sys/fs/pstore/dmesg-erst-1
32
33		The expectation is that all files in /sys/fs/pstore/
34		will be saved elsewhere and erased from persistent store
35		soon after boot to free up space ready for the next
36		catastrophe.
37
38		The 'kmsg_bytes' mount option changes the target amount of
39		data saved on each oops/panic. Pstore saves (possibly
40		multiple) files based on the record size of the underlying
41		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 multiple
45		backends are available, the preferred backend may be
46		set by passing the pstore.backend= argument to the kernel at
47		boot time.
48