Re: [MLUG] "missing" files after hard crash or power failure

["shawn parker" <EMAIL:PROTECTED>]

that makes sense. i'll check with the dba and sde admin to see if it
has a high file usage.

thanks!

On 4/2/07, Stephen Montgomery-Smith <EMAIL:PROTECTED> wrote:
> Here is my guess.  /home/sde1 are updated a lot.  So the directories
> (which consists of a data file containing the names of the files in it,
> along with their associated inodes) is kept in cache - perhaps by the
> OS, but if not then by the hard drive itself.  So when the power goes
> out, the data in the directory (i.e. the associations of the names with
> the inodes) is lost.  All you are left with is the name of the
> directory, which presumably is a rather old association of names with
> inodes - inodes which no longer point to anything useful, and so in the
> fsck you presumably did after the crash these names get removed.
>
>
> shawn parker wrote:
> > i have two cases, now, where data went mysteriously "missing" after a
> > crash or power failure.
> >
> > crash 1:
> >
> > server3 hard locked and had to be manually power-cycled. upon
> > successful startup, all files in /home/sde1 and /arcgis/sde1 were
> > missing. *not* the directory structure, just the data files in each
> > directory.
> >
> > power failure 1:
> >
> > ups had a capacitor blow sending it into bypass. the breaker tripped
> > causing a full power loss to all server racks (bad luck, i know...also
> > a 22 hour day last friday). after finally getting everything back on,
> > the same issue as above happened on a different server; server1.
> >
> > two different boxes, same problem.
> >
> > no other directories or users were affected, both times it was
> > /home/sde1 and /arcgis/sde1. the home directories are local to each
> > server and the /arcgis partition/mount-point is a different SAN LUN
> > for each server.
> >
> > the only thing similar between the two is the naming used.
> >
> > if "rm" was used, it would need to be recursive to remove all the
> > files from different directories, but since the directories themselves
> > are still available, i doubt this is the problem.
> >
> > if a combo find+regexp was used, it could be possible, but that would
> > be a complex command to issue, and only two users would have the
> > ability to issue it and remove these files, sde1 and root. i know that
> > i didn't do it.
> >
> > from a security perspective, it could be said that user sde1 did
> > something she shouldn't have since /home/sde1 was cleaned out as well
> > (erasing history, etc) but, since we use a net intelligence logger and
> > can't see anything "bad" i doubt this is the case, either.
> >
> > also note, that /arcgis/sde2 and /home/sde2 were fine along with all
> > other users and SAN LUNs.
> >
> > anyone have any ideas?
> >
> > both servers are fully patched red hat enterprise v3 running oracle
> > and gis.
> >
> > the first time it was a test environment, no harm no foul. the second
> > time, though, it was production.
> >
> > the issue is resolved, i simply restored the data from tape. but, i
> > would like to know why it happened in the first place.
> >
>
>
> _______________________________________________
> members mailing list
> EMAIL:PROTECTED
> http://mlug.missouri.edu/mailman/listinfo/members


--
http://silolabs.dnsalias.net/~sparker/pubkey.txt

_______________________________________________
members mailing list
EMAIL:PROTECTED
http://mlug.missouri.edu/mailman/listinfo/members