Thread: PG periodic Error on W2K

I'm running PG 8.2.3 on We doze 2000 Server. (Should I apologise for
that up front to appease the masses?)

I am periodically getting errors pop up on the server console of the
following nature:

The File or directory D:\PostgresQL\Data\global\pgstat.stat is corrupt
and unreadable. Please run the Chkdsk utility.

and

The file or directory D: is corrupt and unreadable. Please run the
Chkdsk utility.

Now, per the errors suggestion I have run the chkdsk utility with a /X
/F switch to do a complete check on reboot before mounting the volume.

This showed no errors.

I can also open the mentioned file - pgstat.stat - using notepad or any
other program without mention of corruption and the data within the file
looks to be uniform suggesting it is fine.

Strangely enough, this error was being presented on the last server I
had it running on, and was in fact one of the reasons I moved it - I
assumed the error was due to dodgy disks but this seems a bit much of a
coincidence.

I know these errors are not coming directly from Postgres, but does
anyone else have problems (or has had previously) of a similar nature or
any suggestions on where it may be?

As a side-note, this server is RAID controlled, the D drive has

    3 disks in the array - I would therefore have assumed that if there
was a problem with one of the disks then the server would carry on using
the other disks.

I can find no performance degradation in Postgres, the service and
connections et al. keep on operating as though there was nothing wrong,
but the errors continue to pop up sporadically on the console.

Thoughts? Ideas? Suggestions? Should I bugger off?

--
Paul Lambert
Database Administrator
AutoLedgers

Paul Lambert wrote:
> I'm running PG 8.2.3 on We doze 2000 Server. (Should I apologise for
> that up front to appease the masses?)

Probably ;)

>
> I am periodically getting errors pop up on the server console of the
> following nature:
> This showed no errors.
>
> I can also open the mentioned file - pgstat.stat - using notepad or any
> other program without mention of corruption and the data within the file
> looks to be uniform suggesting it is fine.

Try turning off stats. However you will need to run vacuum using some
other method.

Joshua D. Drake

>
> Thoughts? Ideas? Suggestions? Should I bugger off?
>

The Windows port is still young, we are here to help. Try the above and
see if the problem goes away :)

Sincerely,

Joshua D. Drake


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Joshua D. Drake wrote:
> Paul Lambert wrote:
>> I'm running PG 8.2.3 on We doze 2000 Server. (Should I apologise for
>> that up front to appease the masses?)
>
> Probably ;)

I propound to all my sincerest of apologies for installing what I
believe to be a marvel of human creation in Postgres on what most
believe to be the ultimate travesty of what some claim to be an
operating system in Macrohard Webloze.

I would be delighted to offer my assurance that such a farce would never
again take place, but I have about forty such installations to do when
my development is complete :(

>
>> I am periodically getting errors pop up on the server console of the
>> following nature:
>> This showed no errors.
>>
>> I can also open the mentioned file - pgstat.stat - using notepad or any
>> other program without mention of corruption and the data within the file
>> looks to be uniform suggesting it is fine.
>
> Try turning off stats. However you will need to run vacuum using some
> other method.
>
> Joshua D. Drake
>
>> Thoughts? Ideas? Suggestions? Should I bugger off?
>>
>
> The Windows port is still young, we are here to help. Try the above and
> see if the problem goes away :)
>
> Sincerely,
>
> Joshua D. Drake
>
>

I should mention that this particular database is my development server
so at this point it doesn't have any data because I'm still trying to
get the program prepared that populates is. (All tables have zero rows)

I don't think vacuuming will do much for me anyway so I have no problems
if I can't run it :)

I'll turn off stats and see what happens.

Thanks.

--
Paul Lambert
Technical Support Team Leader and Database Administrator
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On Thu, Mar 01, 2007 at 09:44:19AM +0900, Paul Lambert wrote:
> I'm running PG 8.2.3 on We doze 2000 Server. (Should I apologise for
> that up front to appease the masses?)
>
> I am periodically getting errors pop up on the server console of the
> following nature:
>
> The File or directory D:\PostgresQL\Data\global\pgstat.stat is corrupt
> and unreadable. Please run the Chkdsk utility.
>
> and
>
> The file or directory D: is corrupt and unreadable. Please run the
> Chkdsk utility.
>
> Now, per the errors suggestion I have run the chkdsk utility with a /X
> /F switch to do a complete check on reboot before mounting the volume.
>
> This showed no errors.
>
> I can also open the mentioned file - pgstat.stat - using notepad or any
> other program without mention of corruption and the data within the file
> looks to be uniform suggesting it is fine.
>
> Strangely enough, this error was being presented on the last server I
> had it running on, and was in fact one of the reasons I moved it - I
> assumed the error was due to dodgy disks but this seems a bit much of a
> coincidence.
>
> I know these errors are not coming directly from Postgres, but does
> anyone else have problems (or has had previously) of a similar nature or
> any suggestions on where it may be?

They are, as you say, generated by Windows, and not PostgreSQL. They're
a clear indication of either hardware problem, driver problem or windows
bug (which we all know don't exist, so it must be one of the first).

They can *not* be caused by a bug in PostgreSQL - no more than a kernel
oops in linux is the fault of PostgreSQL. Now, we do push the filesystem
and disk layer in an unusual way with the pgstats writes, gievn that we
rewrite the same file over and over and over and over again at very
short intervals. But nothing says we're not allowed to do that :-)

The reason you acn open it with notepad is most likely that it's a
different file - the file is deleted and recreated at a rate of at least
twice per second, when there is activity happening in the database. The
error is more a "filesystem is broken" message than "this file is
broken".


> As a side-note, this server is RAID controlled, the D drive has
>
>    3 disks in the array - I would therefore have assumed that if there
> was a problem with one of the disks then the server would carry on using
> the other disks.

You would hope so. But the problem could be in the actual RAID
controller. There are a lot of el-cheapo RAID-boards out there that
really do more harm than good. Then there are of course a lot of very
nice controllers as well :-) Which one do you have?

Also, it could very well be a driver problem - have you verified that
you're on the latest version?


> I can find no performance degradation in Postgres, the service and
> connections et al. keep on operating as though there was nothing wrong,
> but the errors continue to pop up sporadically on the console.
>
> Thoughts? Ideas? Suggestions? Should I bugger off?

Thoughts: scary (for you).
Ideas: see above.
Suggestions: get it fixed. Next time it might be your datafile or WAL.
Bugger off: Nah, find out what it was and let us know instead :-)


On Wed, Feb 28, 2007 at 04:52:15PM -0800, Joshua D. Drake wrote:
> Try turning off stats. However you will need to run vacuum using some
> other method.

While this will get rid of the message (most likely) you're only curing
the symptoms and not the problem. As I said above, next time it might be
a file that contains important data.

//Magnus

Magnus Hagander <magnus@hagander.net> writes:
> On Thu, Mar 01, 2007 at 09:44:19AM +0900, Paul Lambert wrote:
>> I am periodically getting errors pop up on the server console of the
>> following nature:
>> The File or directory D:\PostgresQL\Data\global\pgstat.stat is corrupt
>> and unreadable. Please run the Chkdsk utility.

> They can *not* be caused by a bug in PostgreSQL - no more than a kernel
> oops in linux is the fault of PostgreSQL. Now, we do push the filesystem
> and disk layer in an unusual way with the pgstats writes, gievn that we
> rewrite the same file over and over and over and over again at very
> short intervals. But nothing says we're not allowed to do that :-)

I'm wondering whether the message is coming from the kernel, or some
sort of file-scanning utility that gets confused when a file is deleted
while it's looking at it.

            regards, tom lane

On Thu, Mar 01, 2007 at 10:45:16AM -0500, Tom Lane wrote:
> Magnus Hagander <magnus@hagander.net> writes:
> > On Thu, Mar 01, 2007 at 09:44:19AM +0900, Paul Lambert wrote:
> >> I am periodically getting errors pop up on the server console of the
> >> following nature:
> >> The File or directory D:\PostgresQL\Data\global\pgstat.stat is corrupt
> >> and unreadable. Please run the Chkdsk utility.
>
> > They can *not* be caused by a bug in PostgreSQL - no more than a kernel
> > oops in linux is the fault of PostgreSQL. Now, we do push the filesystem
> > and disk layer in an unusual way with the pgstats writes, gievn that we
> > rewrite the same file over and over and over and over again at very
> > short intervals. But nothing says we're not allowed to do that :-)
>
> I'm wondering whether the message is coming from the kernel, or some
> sort of file-scanning utility that gets confused when a file is deleted
> while it's looking at it.

That specific message comes from the kernel.

//Magnus

MargaretGillon@chromalloy.com wrote:
>
>  > Date: Thu, 01 Mar 2007 10:06:44 +0900
>  > From: Paul Lambert <paul.lambert@autoledgers.com.au>
>  > To: "Joshua D. Drake" <jd@commandprompt.com>
>  > Cc: pgsql-general@postgresql.org
>  > Subject: Re: PG periodic Error on W2K
>  > Message-ID: <45E62724.6000200@autoledgers.com.au>
>  >
>  >
>  > I propound to all my sincerest of apologies for installing what I
>  > believe to be a marvel of human creation in Postgres on what most
>  > believe to be the ultimate travesty of what some claim to be an
>  > operating system in Macrohard Webloze.
>  >
>  >> [text excluded here]
>  >
>  > I would be delighted to offer my assurance that such a farce would never
>  > again take place, but I have about forty such installations to do when
>  > my development is complete :(
>  >
>  > Paul Lambert
>
> Hi Paul,
>
> Have you thought of running the Postgresql on a Linux box and then
> developing your application to use the Postgresql server via ODBC?
>
> I am in a Windows environment on a Windows / Novell network. We still
> use Novell for log-on and security management. I develop in Visual
> FoxPro because the IT head wants to keep us on Windows clients but he
> agreed to let me try developing with a Linux server. I have been working
> with Postgresql on a Redhat 9 server for a couple years now and it is
> much more stable (and more secure) than our SQLServer databases on a
> Windows 2000 server.
>
> *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
> *** ***
> Margaret Gillon, IS Dept., Chromalloy Los Angeles, ext. 297

I've put thought of running it on Linux... a lot of thought... but I
haven't for 2 reasons.

1.) I've had very limited exposure to Linux, most of my work is done in
an OpenVMS environment with some in Weendoze, I wouldn't feel
comfortable configuring a Linux environment let alone configuring it
properly.

2.) All of our customers run Weenblows servers and also don't have the
expertise to maintain a linux server, it's a lot easier for us to sell
our product to them if we can just install it on their existing server
and have them not worry about upgrading or adding anything to their
server room.

Can I put in another plug for an OpenVMS port? Or would I have to do the
work myself? ;)

--
Paul Lambert
Database Administrator
AutoLedgers

Magnus Hagander wrote:
> On Thu, Mar 01, 2007 at 10:45:16AM -0500, Tom Lane wrote:
>> Magnus Hagander <magnus@hagander.net> writes:
>>> On Thu, Mar 01, 2007 at 09:44:19AM +0900, Paul Lambert wrote:
>>>> I am periodically getting errors pop up on the server console of the
>>>> following nature:
>>>> The File or directory D:\PostgresQL\Data\global\pgstat.stat is corrupt
>>>> and unreadable. Please run the Chkdsk utility.
>>> They can *not* be caused by a bug in PostgreSQL - no more than a kernel
>>> oops in linux is the fault of PostgreSQL. Now, we do push the filesystem
>>> and disk layer in an unusual way with the pgstats writes, gievn that we
>>> rewrite the same file over and over and over and over again at very
>>> short intervals. But nothing says we're not allowed to do that :-)
>> I'm wondering whether the message is coming from the kernel, or some
>> sort of file-scanning utility that gets confused when a file is deleted
>> while it's looking at it.
>
> That specific message comes from the kernel.
>
> //Magnus
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>        choose an index scan if your joining column's datatypes do not
>        match
>
>

Still getting the errors, but I managed to convince the powers that be
to order me a fancy new server so we'll see how that goes when it arrives.

Thanks again to all for the info though.

--
Paul Lambert
Database Administrator
AutoLedgers