Re: READ ONLY & I/O ERROR

On 2/12/2009 11:35 PM, Scott Marlowe wrote:
> (please use text only email to the list)
>
> On Wed, Dec 2, 2009 at 7:51 AM, Sam Jas<samjas33@yahoo.com>  wrote:
>>
>> We are getting the below errors after 20 or 25 days of database creation.
>>
>> ERROR: could not open relation 1919829/1152694/1921473: Read-only file system
>> ERROR: could not read block 312320 of relation 1964206/1152694/1981329: Input/output error
>
> PostgreSQL cannot make a file system read only.  The OS does that.
>
> What do your system logs in /var/log have to say when this happens?
> There's got to be more context in there than we're getting evidence of
> here on the list.

In particular, if you're on a Linux system check the output of the
"dmesg" command. I expect to see warnings about file system errors and
about the file system being re-mounted read-only. I won't be surprised
to see disk/raid errors either.

>> If we create a new database the problem is repeated after 20 or 25 days. Until then we don't have any issues with
thenew database. 
>
> My guess is that it's not a fixed number, just what you've seen so
> far, could happen in a day or a month or a year.

Do you do any RAID scrubbing? On what schedule? Do you test the disks
that are part of your RAID array using their internal SMART diagnostics?

Is your server ever hard-reset or rebooted due to loss of power?
(PostgreSQL is fine with this on a proper setup, but if you have a buggy
RAID controller or one that caches writes without a battery backup, it's
going to have issues).

--
Craig Ringer