On 10/14/2013 12:50 PM, CeDeROM wrote:
On Mon, Oct 14, 2013 at 6:47 PM, Adam Vande More <amvandem...@gmail.com> wrote:
On Mon, Oct 14, 2013 at 11:34 AM, David Demelier
<demelier.da...@gmail.com>wrote:
Why? SU+J is enabled by default. Isn't the purpose of a journaled file
system to ensure that any bad shutdown will protect data?
As already stated, those measures are to preserve fs integrity eg meta data
is in sync. It doesn't ensure that all the outstanding writes are
committed to disk in the event of a power outage.
Then why random files gets damaged as well even they are not
accessed/written on power loss? :-)
Random files can be affected because the sectors of the hard disk
containing the directory entries for those files, not the file data
itself, may be damaged (ie: the directory was in the process of being
written OR the pointer to that SECTOR was in the process of being written).
It doesn't mean a file was in active use, just that a chunk of the disk
with data relevant to that file was. Keep in mind, one sector of disk
may have data for a dozen files in it (or more). Damage doesn't have to
occur because a given file was in use at the time of a crash.
If your power grid is prone to failures or blips, I strongly suggest
investing in a UPS.
Brad
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