Re: What is postgresql status? I'm not sure

On 25/08/2011 2:09 AM, Mcleod, John wrote:
>
> Hello all,
>
> Don't shoot me, I'm just the fella sweeping up after a departure.
>
> I'm supporting a web site with mapping features using Mapserver and
> PostgreSql 7.5 for windows.
>
> Recently, my mapping features went down.
>
> Error messages that display are the following...
>
> Warning: pg_query(): Query failed: ERROR: xlog flush request
> 0/34D85078 is not satisfied --- flushed only to 0/34CD4518 CONTEXT:
> writing block 0 of relation 394198/412173 in
> C:\ms4w\Apache\htdocs\davison\mapping\gis1\viewparcel_nolink.php on
> line 10
>

Sounds like a disk fault or disk-full issue.

>
> It looks to me that the query failed based on a hard drive issue.
> Well, over the weekend we swapped out the hard drive for new. The
> site comes back fine but I'm still receiving the error.
If you have actual data corruption as a result of the disk failure, you
may have to restore from a backup. Theoretically data corruption
shouldn't happen if a HDD just starts failing writes, but in reality it
can happen due to possible resulting file-system corruption, OS issues,
or the disk actually returning corrupted blocks on reads.

> C:\ms4w\apps\pgsql75win\data>del postmaster.pid
>
> Could Not Find C:\ms4w\apps\pgsql75win\data\postmaster.pid
>

Eek, who/what is doing that?!?

Don't delete the postmaster pid file. If you do so without making
EXTREMELY sure there are no backends still running, you risk severe
database corruption if you then start a new postmaster.

> LOG: database system was shut down at 2011-08-24 17:30:14 Eastern
> Standard Time
>
> LOG: checkpoint record is at 0/34CD4078
>
> LOG: redo record is at 0/34CD4078; undo record is at 0/0; shutdown TRUE
>
> LOG: next transaction ID: 1198832; next OID: 1772830
>
> LOG: database system is ready
>
> I'm not sure if the database is up or not.
>

Well, it's running.

> I don't even see postgresql or mapserver as Windows services.
>

How did you start it? If you didn't start it with "net service" or using
the "services.msc" MMC snapin, it won't start as a service. It looks
like you used some kind of batch file to start it under your own user
account instead, but you haven't shown the full command line(s) involved.

--
Craig Ringer