/ is remounted when the power cable is plugged in/out

/ is remounted when the power cable is plugged in/out

[Toralf Förster]

At my ThinkPad T420 I get these syslog messages when I plug off the power cable of a system
booted from an external USB drive (root / is /dev/sdb3):


2013-01-14T22:20:46.028+01:00 n22 kernel: ata1.00: failed to get Identify Device Data, Emask 0x1
2013-01-14T22:20:46.029+01:00 n22 kernel: ata1.00: failed to get Identify Device Data, Emask 0x1
2013-01-14T22:20:46.029+01:00 n22 kernel: ata1.00: configured for UDMA/100
2013-01-14T22:20:46.029+01:00 n22 kernel: ata1: EH complete
2013-01-14T22:20:46.029+01:00 n22 kernel: sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA                     
2013-01-14T22:20:46.083+01:00 n22 kernel: thinkpad_acpi: unknown possible thermal alarm or keyboard event received                                     
2013-01-14T22:20:46.083+01:00 n22 kernel: thinkpad_acpi: unhandled HKEY event 0x6040                                                                   
2013-01-14T22:20:46.083+01:00 n22 kernel: thinkpad_acpi: please report the conditions when this event happened to ibm-acpi-devel@lists.sourceforge.net 
2013-01-14T22:20:46.085+01:00 n22 kernel: thinkpad_acpi: EC reports that Thermal Table has changed                                                     
2013-01-14T22:20:46.000+01:00 n22 logger: ACPI event : ibm/hotkey HKEY 00000080 00006040                                                               
2013-01-14T22:20:46.000+01:00 n22 logger: ACPI event : ibm/hotkey HKEY 00000080 00006030                                                               
2013-01-14T22:20:46.305+01:00 n22 kernel: EXT4-fs (sdb3): re-mounted. Opts: commit=600                                                                 


and when I plug in the power cable I get the similar events :


2013-01-14T22:20:51.476+01:00 n22 kernel: ata1.00: failed to get Identify Device Data, Emask 0x1
2013-01-14T22:20:51.477+01:00 n22 kernel: ata1.00: failed to get Identify Device Data, Emask 0x1
2013-01-14T22:20:51.477+01:00 n22 kernel: ata1.00: configured for UDMA/100
2013-01-14T22:20:51.477+01:00 n22 kernel: ata1: EH complete
2013-01-14T22:20:51.477+01:00 n22 kernel: sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
2013-01-14T22:20:51.514+01:00 n22 kernel: thinkpad_acpi: unknown possible thermal alarm or keyboard event received
2013-01-14T22:20:51.514+01:00 n22 kernel: thinkpad_acpi: unhandled HKEY event 0x6040
2013-01-14T22:20:51.514+01:00 n22 kernel: thinkpad_acpi: please report the conditions when this event happened to ibm-acpi-devel@lists.sourceforge.net
2013-01-14T22:20:51.516+01:00 n22 kernel: thinkpad_acpi: EC reports that Thermal Table has changed
2013-01-14T22:20:51.000+01:00 n22 logger: ACPI event : ibm/hotkey HKEY 00000080 00006040
2013-01-14T22:20:51.000+01:00 n22 logger: ACPI event : ibm/hotkey HKEY 00000080 00006030
2013-01-14T22:20:52.170+01:00 n22 kernel: EXT4-fs (sdb3): re-mounted. Opts: commit=0


b/c of the unknown event 0x6040 the ibm acpi list is Cc'ed, but what makes me really wondering is
why / is remounted.


-- 
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3

Re: / is remounted when the power cable is plugged in/out

[Matthew Garrett]

On Mon, Jan 14, 2013 at 10:26:13PM +0100, Toralf Förster wrote:
> b/c of the unknown event 0x6040 the ibm acpi list is Cc'ed, but what makes me really wondering is
> why / is remounted.

Because something in your userspace is changing the filesystem commit 
interval.

-- 
Matthew Garrett | mjg59@srcf.ucam.org