[comp.sys.next] Help! Power failure Recovery

rdd@wuphys.wustl.edu (Rakhal D. Dave) (05/30/91)

O Wizards and Gurus:

I was using Edit to edit a TeX file containing a section from my thesis when
the lights flickered. Anticipating a power failure I did a command s to save
the file. Within about 5 seconds after that the power failed. When
eventually I rebooted My file was there in the directory but empty. Luckily
I had the corresponding dvi file made just 10 min. before the power failure
but no TeX version. I am going to have to rewrite the TeX version now from
the printout of the dvi file. Could my lost file be recovered somehow? I
know that vi has recovery capability in such situations. Could there be a
temporary file somewhere?.

Sometime back I had requested information on the possibility of making a
Banner using the next laser printer. Is this possible? In particular will
it accept a continuous ream of paper through the manual feed. Also what
software is best to produce the banner so that characters may be split
across pages without break.

	   Look forward for input from the net

					 -Rakhal Dave

steve@tweedledee.ucsb.edu (Steve Trainoff) (05/31/91)

In article <1991May30.040830.28055@wuphys.wustl.edu> rdd@wuphys.wustl.edu  
(Rakhal D. Dave) writes:
> O Wizards and Gurus:
> 
> I was using Edit to edit a TeX file containing a section from my thesis when
> the lights flickered. Anticipating a power failure I did a command s to save
> the file. Within about 5 seconds after that the power failed. When
> eventually I rebooted My file was there in the directory but empty. Luckily
> I had the corresponding dvi file made just 10 min. before the power failure
> but no TeX version. I am going to have to rewrite the TeX version now from
> the printout of the dvi file. Could my lost file be recovered somehow? I
> know that vi has recovery capability in such situations. Could there be a
> temporary file somewhere?.
> 	   Look forward for input from the net
> 
> 					 -Rakhal Dave


The problem you experienced was due to disk cacheing.  When you used CMD-s the  
file was "saved" in the disk cache.  The actual data probably wasn't written to  
disk before the power went out.  The unix command "sync" manually forces the   
cache to be written out to the disk.  There is a daemon called "update" which  
calls "sync" every 30 seconds to try to prevent just the problem you  
experienced.  You just got unlucky.  If the power failure had been a few  
seconds later things would have been fine.

--
..STeve
------------------------------------
Insert pity maxim here...
steve@tweedledee.ucsb.edu (NeXT mail)