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
