Re: 2.6.0-test2-mm3 and mysql

["Sergey S. Kostyliov" <rathamahata@php4.ru>]

On Thursday 28 August 2003 23:10, Heikki Tuuri wrote:
> Sergey,
>
> ----- Original Message -----
> From: "Sergey S. Kostyliov" <rathamahata@php4.ru>
> To: "Heikki Tuuri" <Heikki.Tuuri@innodb.com>;
> <linux-kernel@vger.kernel.org> Sent: Thursday, August 28, 2003 10:01 PM
> Subject: Re: 2.6.0-test2-mm3 and mysql
>
> > Hi Heikki,
> >
> > On Thursday 28 August 2003 21:59, Heikki Tuuri wrote:
> > > Sergey,
> > >
> > > does it always crash when you start mysqld?
> >
> > Yes It was always crashing until I deleted all InnoDB files and restored
> > InnoDB tables from backup.
> >
> > > It is page number 0 in the InnoDB tablespace. That is, the header page
>
> of
>
> > > the whole tablespace!
> > >
> > > The checksums in the page are ok. That shows the page was not corrupted
>
> in
>
> > > the Linux file system.
> > >
> > > InnoDB is trying to do an index search, but that of course crashes,
>
> because
>
> > > the header page is not any index page.
> > >
> > > The reason for the crash is probably that a page number in a pointer
>
> record
>
> > > in the father node of the B-tree has been reset to zero. The corruption
>
> has
>
> > > happened in the mysqld process memory, not in the file system of Linux.
> > > Otherwise, InnoDB would have complained about page checksum errors.
> > >
> > > No one else has reported this error. I have now added a check to a
>
> future
>
> > > version of InnoDB which will catch this particular error earlier and
>
> will
>
> > > hex dump the father page.
> >
> > Yes, now it seems for me that this particular crash in not related to
>
> linux
>
> > kernel at all.
> > The funny thing I've managed to get another InnoDB crash on the same box
> > http://sysadminday.org.ru/linux-2.6.0-test4_InnoDB_crash-20030828
> > which in turn was posted to linux-kernel over a two hours ago.
> > This time the cheksums are different :(
>
> ok, this time the corruption probably happened in the file cache, or the
> file system of Linux, or in the hardware.
>
> It is not at all surprising that you encounter memory corruption and file
> corruption in the same computer. That is a common pattern if these problems
> appear at all.
>
> Do you have a swap partition? I do not know Linux well enough, but in
> theory, file or disk corruption could cause also memory corruption if pages
> of the process memory get swapped to disk.

Yes, the swap is used on this box.

rathamahata@dev rathamahata $ free -k
             total       used       free     shared    buffers     cached
Mem:       1035248     860740     174508          0      32676     581852
-/+ buffers/cache:     246212     789036
Swap:      8969484     195136    8774348