Re: DB fails to start: "Could not read from file "pg_clog/0003" at offset 212992: No error.

> Crashed how? Did the *server* crash, or the database?
> When is your last backup from?
> Have you made a complete file-system level copy of the database yet?

I don't know how it crashed yet, I'm checking what the reason was.
We will check if we have a recent backup.
Yes, we made a compile file-system level copy of the database.

> There's no sign of corruption and an issue with the clog doesn't imply data coruption, but you should still take a complete copy before proceeding unless your backups are current and trusted.

What does the issue with clog imply?
We have 5 files in the clog folder:

1. Files 0000-0002 are 256K filled with 'U'
2. File 0003 is 184K and at the end there is junk like 'ZZZZZiiiiiii(tm)eiY'
3. File 0004 is 24K and filled with 'U'

> Please perform below steps:
> 1. Backup the current pg_clog/0003 file in different directory
> 2. Create a file by assumption of make the uncommitted record as they haven't been committed. command as follows:
> dd if=/dev/zero of=<data directory location>/pg_clog/0003 bs=256K count=1
> This is just a 256k zero-byte file. Here's one I made earlier:
> http://www.postnewspapers.com.au/~craig/0003.zip

I performed the procedure and the db started. How can I check if it's corrupted or not?

> Create a file by assumption of make the uncommitted record as they haven't been committed. command as follows:

What does the file replacement actually did? Which records is marked as uncommitted?

Thanks a lot for your help