Hi, Ian Westmacott wrote: >Mauri, I'm no expert but I can tell you what I know. We >have experienced this same problem, and I asked a >similar question not too long ago. > >- This is probably due to some sort of I/O problem. In > our case, it occurs very frequently on reboots, and > it appears to be related to dirty buffers not being > flushed out when the partition is unmounted. Look > into a newer kernel, and/or newer/different > filesystem (we have seen this in various flavors > of the 2.4.6 kernel with XFS, JFS and EXT3). > > Uh. As our cheap server is a virtual machine under a virtuozzo (http://www.sw-soft.com/products/virtuozzo/) I have no control over what kernel to run or what filesystem to use. Nor has there been frequent reboots. I have restarted the virtual server twice in 4 months and the provider has done it once since production started. But as it might still be a filesystem problem (vzfs) I should try to find documentation on vzfs to see if I can do something to increase its "reliability" or if the provider can do that. The client side did fail very frequently for a while due non mature w-lan card driver and that might have caused the corruption that did not got fixed properly by my inept attempts and still lurks around. >- If you have invalid page headers, you should take a > look at the run-time parameter zero_damaged_pages. > You can use this to fix up a table (losing the data > on the bad pages). > > > Thanks I will try that. >- We have not found a way around the missing log file > problem. This appears to end up locking some rows > forever. > > It seems to me that the best course for action for us would be: Zeroing damaged pages. Dump every database excluding templates. Shutdown. Remove provider's postgresql-rpms and install the latest rpms on 7-series of Postgresql from Fedora legacy/pgfoundry. Restore databases. Manually merge changes from older backups that got zeroed. Upgrade client-side to the same version of postgresql as the server side. Recompile libraries and applications. Startup. Backup. Increase frequenzy of backups and hope for the best.
