Date: Thu, 8 Jun 2017 20:47:40 +0200 From: Polytropon <freebsd@edvax.de> To: Andrea Venturoli <ml@netfence.it> Cc: freebsd-questions@freebsd.org Subject: Re: Panic on external HD disconnection Message-ID: <20170608204740.9ad9b1c3.freebsd@edvax.de> In-Reply-To: <929de353-94c4-cbf2-9b33-67f60b007a71@netfence.it> References: <929de353-94c4-cbf2-9b33-67f60b007a71@netfence.it>
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On Thu, 8 Jun 2017 15:12:49 +0200, Andrea Venturoli wrote:
> Today I was taking a backup to an external UFS HD when I accidentally
> touched the cable and it sort of unplugged.
So the disk was mounted at that specific point in time?
Partially understandable. The system will somehow react
to a mass media device surprisingly removed when it is
writing to it...
> While I understand this falls either into hardware or "stupid user"
> category of panics, is a whole crash normal?
That depends on the kind of operation the system has been
performing at that moment. Disconnecting an unmounted
device isn't a problem, and a mounted device which is not
written to (or read from) often results in a normal application
error.
> Or should I expect better resilience, like fail that filesytem, spit a
> whole bunch of offenses at me, but keep the on working with the rest,
> and look for something wrong on my setup?
In case of accidental UFS disconnect, reconnect the drive,
do _not_ attempt to mount it right away, but instead perform
a full fsck ("fsck -yf /dev/da0", for example) of the file
system on that disk. In best case, fsck will repair any
damages that did appear, and then return the file system into
a consistent state, ready for mounting.
But as I said: It highly depends on _what exactly_ was happening
to the disk when it was disconnected...
--
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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