On Thu, Oct 3, 2013 at 2:34 AM, Rob van der Heij <rvdh...@gmail.com> wrote:
> On Wed, Oct 2, 2013 at 7:17 PM, Donald Russell <russell....@gmail.com > >wrote: > > > > > In the case I'm currently working on, a ".so" file (binary) has a chunk > of > > plain text in the middle of it. The "chunk" is 4K bytes long, and is a > > piece of a program listing. 4K is the block size of the underlying DASD. > > > > I am now in the process of trying to find when this happened by restoring > > backup copies and seeing if I can narrow the time frame down. > > > > Was either or both of these files supposed to be written? The .so file > would be written only when you install the package. If the .so was not > written, the origin of the text might point to the cause. And what's > underneath; is it a plain device or is there LVM or md in between? > > Both files are expected to be written, not necessarily at the same time. The listing piece is not associated with the .so file. > Since you mention journaling errors, did you have fsck repair things that > could actually have created this? (we've seen that in the past with fsck on > ReiserFS disks). The minidisk isn't R/O, is it? I think that has been > fixed now, but initially we had problems where Linux eventually would drop > dirty blocks when it couldn't write them to disk. > > The journaling errors were from a long time ago, and yes, we ran fsck -y to fix all the errors. Are you saying that fsck -y (or answering y to an individual prompt) may cause file corruption that looks like this? That would explain why a single block of data gets replaced in the middle of a file. > Can you DDR the minidisk to another place and link thata in another Linux > guest? That way you can run fsck as you like. > > Yes, we take the system down weekly to do a DDR backup to another complete set of DASD... I can bring that DDR copy up in single user mode. (We also use a linux backup utility to take daily backups.) ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
