Thread

1. Re: [HACKERS] Recovery on incomplete write

   Tom Lane <tgl@sss.pgh.pa.us> — 1999-09-28T14:39:22Z

   "Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
   > I have wondered that md.c handles incomplete block(page)s
   > correctly.
   > Am I mistaken ?
   
   I think you are right, and there may be some other trouble spots in that
   file too.  I remember thinking that the code depended heavily on never
   having a partial block at the end of the file.
   
   But is it worth fixing?  The only way I can see for the file length
   to become funny is if we run out of disk space part way through writing
   a page, which seems unlikely...
   
   			regards, tom lane
   
   

2. Re: [HACKERS] Recovery on incomplete write

   Bruce Momjian <maillist@candle.pha.pa.us> — 1999-09-28T14:54:26Z

   > "Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
   > > I have wondered that md.c handles incomplete block(page)s
   > > correctly.
   > > Am I mistaken ?
   > 
   > I think you are right, and there may be some other trouble spots in that
   > file too.  I remember thinking that the code depended heavily on never
   > having a partial block at the end of the file.
   > 
   > But is it worth fixing?  The only way I can see for the file length
   > to become funny is if we run out of disk space part way through writing
   > a page, which seems unlikely...
   > 
   
   That is how he got started, the TODO item about running out of disk
   space causing corrupted databases.  I think it needs a fix, if we can.
   
   -- 
     Bruce Momjian                        |  http://www.op.net/~candle
     maillist@candle.pha.pa.us            |  (610) 853-3000
     +  If your life is a hard drive,     |  830 Blythe Avenue
     +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026
   
   

3. RE: [HACKERS] Recovery on incomplete write

   Hiroshi Inoue <inoue@tpf.co.jp> — 1999-09-29T07:20:14Z

   > -----Original Message-----
   > From: Bruce Momjian [mailto:maillist@candle.pha.pa.us]
   > Sent: Tuesday, September 28, 1999 11:54 PM
   > To: Tom Lane
   > Cc: Hiroshi Inoue; pgsql-hackers
   > Subject: Re: [HACKERS] Recovery on incomplete write
   >
   >
   > > "Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
   > > > I have wondered that md.c handles incomplete block(page)s
   > > > correctly.
   > > > Am I mistaken ?
   > >
   > > I think you are right, and there may be some other trouble spots in that
   > > file too.  I remember thinking that the code depended heavily on never
   > > having a partial block at the end of the file.
   > >
   > > But is it worth fixing?  The only way I can see for the file length
   > > to become funny is if we run out of disk space part way through writing
   > > a page, which seems unlikely...
   > >
   >
   > That is how he got started, the TODO item about running out of disk
   > space causing corrupted databases.  I think it needs a fix, if we can.
   >
   
   Maybe it isn't so difficult to fix.
   I would provide a patch.
   
   Regards.
   
   Hiroshi Inoue
   Inoue@tpf.co.jp
   
   
   

4. Re: [HACKERS] Recovery on incomplete write

   Christof Petig <christof.petig@wtal.de> — 1999-09-29T08:39:32Z

   Bruce Momjian wrote:
   
   > >
   > > I think you are right, and there may be some other trouble spots in that
   > > file too.  I remember thinking that the code depended heavily on never
   > > having a partial block at the end of the file.
   > >
   > > But is it worth fixing?  The only way I can see for the file length
   > > to become funny is if we run out of disk space part way through writing
   > > a page, which seems unlikely...
   > >
   >
   > That is how he got started, the TODO item about running out of disk
   > space causing corrupted databases.  I think it needs a fix, if we can.
   
   It does corrupt the database (happened twice to me last week, I'm using the
   current CVS version!). You can't even pg_dump the database - it stops in the
   middle of a line.
   And this happened just because some process went amok and stdout was written
   to a file.
   
   Christof