On Sunday, 17 November 2019 10:30:49 GMT Neil Bothwick wrote: > On Sun, 17 Nov 2019 11:21:18 +0100, n952162 wrote: > > (in fact, that's exactly the situation that I've been confronted with > > and have turned to this mailing list to help me with: X locked up, my > > power-button was unresponsive so I had to force it down (holding the > > power key down for 30 seconds), and on reboot TWO filesystems had to be > > rebuilt by fsck, with substantial loss of organization and of data > > (despite both being ext3/4 journaling filesystems - I just don't > > understand that!) )
As has been mentioned before holding the power button down until the system powers off is equal to a hard shutdown. No write caches are flushed, no data is synced to disk and any writes could be left in mid air resulting in a messed up fs. I always boot with a LiveUSB/CD and perform a fsck without mounting any drives, before I will try to boot the system normally again. If you lose power while the system is idle and no write operations are in process/waiting, then you may well have no loss of data as a result. > Please don't top-post on this list. > > Magic SysReq would probably have helped in those situations. ext3/4 only > journal metadata by default, you can specify a mount option to also > journal data but it impacts performance. When X hangs and I lose the keyboard to the extent where neither Ctrl+Alt+F1, or Ctrl+Alt+Del would work, I will use ssh to connect remotely and stop the hanging process or restat the X server. If ssh is also not working, I use the magic SysReq sequence to stop processes, sync the disks and reboot, or shutdown. I don't recall losing data in such cases, although when I have time I run fsck with Live media just in case. -- Regards, Mick
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