Hi Jules, *,
I think what Stephen meant was that a user, while trying to update the
RLS database (not the data file), might accidentally delete entries or
modify them. The question then is "how long will it be before someone
realizes that some entries have been deleted from the RLS"? Then if you
try to restore from a RLS backup, you have to resolve all the problems
between the current (C) and backup (B) states:
which of the entries present in B but not in C correspond to
accidentally-deleted entries, and which correspond to intentionally
(properly) deleted ones?
JT
On Tue, 2005-01-18 at 09:18, Jules Wolfrat wrote:
>
> > -----Original Message-----
> > From: LHC Computer Grid - Rollout
> > [mailto:[log in to unmask]] On Behalf Of Burke, S (Stephen)
> > Sent: maandag 17 januari 2005 17:46
> > To: [log in to unmask]
> > Subject: Re: [LCG-ROLLOUT] [ATLAS-LCG] Disk failure at Prague
> >
> > LHC Computer Grid - Rollout
> > > [mailto:[log in to unmask]] On Behalf Of Jules
> > Wolfrat said:
> > > The VO doesn't have to notice, the sysadmins are supposed to
> > > detect that
> > > the RLS is broken (e.g. a disk crash) and have to restore,
> > at least at
> > > our site. And we keep backups at least for several weeks.
> >
> > I wasn't thinking of crashes so much as deliberate or
> > accidental corruption
> > by a user/hacker, which might well go un-noticed until
> > someone tries to
> > access one of the missing files.
>
> That's true, but you must make a distinction between the database that
> RLS is and the physical file itself. The file itself can be destroyed
> while the RLS itself still thinks that the file is present. What you
> need is some mechanism to check the integrity of the RLS, e.g. run every
> night a consistency check on the RLS!
>
> Jules
> >
> > Stephen
> >
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