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Re: [OT?] home partition vs. home directory




On Fri, Nov 30, 2018 at 08:39:55PM -0600, David Wright wrote:
> On Fri 30 Nov 2018 at 11:23:57 (-1000), Joel Roth wrote:
> > On Fri, Nov 30, 2018 Cindy-Sue Causey wrote:
> > > Cliff's Notes Version Part I: Flaky USB connections are an important
> > > factor! An accidentally disconnected USB connection can cause data to
> > > become *unknowingly* redirected back to the original directory on the
> > > primary partition. That situation can then potentially lead to loss of
> > > e.g. downloaded data if a user is not always 100% aware of where data
> > > is actually residing at all times.....
> > 
> > I've had problems with flakey connections with external USB
> > drives for years. These problems have occurred with various
> > drives and on two different laptops. The usual result is a
> > disk operation such as 'ls' fails with the message
> > "input/output error". This usually happens after
> > the drive has been idle for some hours. 
> 
> Hm, with poor connections, I find that it's usually the laptop
> moving about which disturbs the cable and causes the problem.
> After idle periods, I just get the message, when it wakes up:
>  usb 4-5: reset high-speed USB device number 4 using ehci-pci
> which I assume may be because the USB was in some sort of
> powersaving mode.
 
> > In my experience, the only case where writes went into
> > directory of the mount point (and not the intended
> > partition) was when the partition was not mounted. Once an
> > I/O error occurs, at least in my system, no further read or
> > write operations to the mount point will succeed. 
> 
> I've never had the mount points overwritten, perhaps because
> of how I set their permissions:
> drwx------ 2 root root 4096 Apr 11  2018 cdrom0/
> and I
> # touch -r cdrom0   all the mount points ...
> so it's easy to see when they're in use as the differing
> permission/ownership/timestamp sticks out.

Nice. I usually make a fstab entry for device
and do a mount -a whenever I plug in a new device.

> It also sounds as if you have   ,errors=remount-ro,
> set as an option in your /etc/fstab entries so that any
> error immediately write-protects the partition; though
> I didn't know that prevents reading as well. Does it?

I don't think my devices got remounted, as in that case
they would be at least read accessible. I do use remount-ro
option. 

One of these I/O errors ends the party completely.
Seems obvious that I should check kern.log for clues
next time I observe it.

I've never lost data due to these  errors, just
can be frustrating if the devices need unplugging and remounting.

^^


> Cheers,
> David.
> 

-- 
Joel Roth