System Hangs When Creating dbspaces
A user on IDS 11.5 (32-bit Windows 2003 under VMware) found that creating ~2GB dbspaces appeared to hang for ~20 minutes after the chunk file reached full size, both via onspaces and OAT. IBM's John Miller explained this is expected for cooked (filesystem) chunks: the server writes page 0 and the last page, then must write every page in between to actually reserve the space, which is where the time goes — raw devices skip this. Art Kagel added that filesystem fragmentation can make those writes slower and suggested defragmenting; another poster suggested more CPU VPs (the user had num=1). No further follow-up from the original poster is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
I'm running Informix 11.5 and I'm trying to build dbspaces, most around 2GB.
When I go to create the space I can see the .000 file growing and it reaches
the intended size. From there something is hanging/freezing for a good 20
minutes until suddenly the system comes around and I have a new dbspace.
So it's creating the space but it's taking forever and I know this isn't
typical. Usually it takes only a couple minutes.
I've tried this with command line using onspaces as well as Open Admin Tool
and the same problem exists.
Any thoughts?
Hello.
I had some troubles creating dbspaces over OAT, using non default
pagesizes (is this your case)?
What engine version are you using (I mean, 32 bits or 64) ? What
architecture?
Regards!
Em Sex, 2010-06-11 Ã s 14:07 -0400, MICHAEL TOPPER escreveu:
> I'm running Informix 11.5 and I'm trying to build dbspaces, most around 2GB.
>
> When I go to create the space I can see the .000 file growing and it reaches
> the intended size. From there something is hanging/freezing for a good 20
> minutes until suddenly the system comes around and I have a new dbspace.
>
> So it's creating the space but it's taking forever and I know this isn't
> typical. Usually it takes only a couple minutes.
>
> I've tried this with command line using onspaces as well as Open Admin Tool
> and the same problem exists.
>
> Any thoughts?
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
Alexandre Marini
Especialista DBA
msn: alexandre_marini@hotmail.com
SEFAZ-MS / SGI-UGSGR / Sistemas IBM-Informix
IBM Certified Professional - Informix Dynamic Server v.10 / v.11
--=-0LEK9qrJqUMKo/Tw+11R
Yes using 4K page file sizes over OAT, although I've also tried just letting
it use the default setting and it makes no difference. I've also tried
onspaces through command line with 4K and it makes no difference.
We're using 32 bit IDS 11.5 on a Windows Server 2003 Standard Edition 32-bit.
Also worth noting this server happens to be a VMWare Server with 2 CPU and 8
GB of RAM. Probably worth mentioned.
Thanks in advance for you help!
Do you see this happening even after increasing the number of CPU vps?
I just tried with 11.50.TC7 on my laptop which has WinXP Pro. The serve=
r
was able to allocate and add a 2Gb dbspace in less than a minute. I hav=
e
"VPCLASS cpu,num=3D2" defined in my onconfig.
Regards,
-- Mirav
Mirav Kapadia (?mirav@us.ibm.com)
IDS Embeddability, Virtualization & Cloud
Computing Team
=
From: "MICHAEL TOPPER" <michaeltopper518@gmail.com> =
=
To: ids@iiug.org =
=
Date: 06/11/2010 01:19 PM =
=
Subject: Re: System Hangs When Creating dbspaces [20377] =
=
Sent by: ids-bounces@iiug.org =
=
Yes using 4K page file sizes over OAT, although I've also tried just
letting
it use the default setting and it makes no difference. I've also tried
onspaces through command line with 4K and it makes no difference.
We're using 32 bit IDS 11.5 on a Windows Server 2003 Standard Edition
32-bit.
Also worth noting this server happens to be a VMWare Server with 2 CPU =
and
8
GB of RAM. Probably worth mentioned.
Thanks in advance for you help!
***********************************************************************=
********
Forum Note: Use "Reply" to post a response in the discussion forum.
=
What you are seeing is expected behavior. You will notice that that the
larger you make the file the longer it will take.
So what is actually happenings is the following. Informix server writes
page
0 then the last page ( at 2GB). If you are using a raw device the
operation stops
here, but because you are using a cooked file there is more work. While at
this
point in time the file shows to be 2GB, but it does not reserve 2GB of
space from the
filesystem. The Informix server has to write every page in between page 1
and the last page
to ensure the space is reserved for this file. This is where the time is
being spent.
Hope it helps,
John F. Miller III
STSM, Support Architect
miller3@us.ibm.com
503-578-5645
IBM Informix Dynamic Server (IDS)
ids-bounces@iiug.org wrote on 06/11/2010 11:07:49 AM:
> [image removed]
>
> System Hangs When Creating dbspaces [20375]
>
> MICHAEL TOPPER
>
> to:
>
> ids
>
> 06/11/2010 11:08 AM
>
> Sent by:
>
> ids-bounces@iiug.org
>
> Please respond to ids
>
> I'm running Informix 11.5 and I'm trying to build dbspaces, most around
2GB.
>
> When I go to create the space I can see the .000 file growing and it
reaches
> the intended size. From there something is hanging/freezing for a good 20
> minutes until suddenly the system comes around and I have a new dbspace.
>
> So it's creating the space but it's taking forever and I know this isn't
> typical. Usually it takes only a couple minutes.
>
> I've tried this with command line using onspaces as well as Open Admin
Tool
> and the same problem exists.
>
> Any thoughts?
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
That config is set to: VPCLASS cpu, num=1, noage I do also see John Miller's response and it seems like a good explanation - using the cooked versus raw files. I appreciate any further advice you might offer.
Sounds like you are building the dbspace from COOKED files. It's possible
that the remaining space on that filesystem is fragmented causing the writes
needed to initiate the file to take longer than usual. Try defagmenting the
filesystem first.
Art
Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
IIUG Board of Directors (art@iiug.org)
Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.
On Fri, Jun 11, 2010 at 2:07 PM, MICHAEL TOPPER
<michaeltopper518@gmail.com>wrote:
> I'm running Informix 11.5 and I'm trying to build dbspaces, most around
> 2GB.
>
> When I go to create the space I can see the .000 file growing and it
> reaches
> the intended size. From there something is hanging/freezing for a good 20
> minutes until suddenly the system comes around and I have a new dbspace.
>
> So it's creating the space but it's taking forever and I know this isn't
> typical. Usually it takes only a couple minutes.
>
> I've tried this with command line using onspaces as well as Open Admin Tool
> and the same problem exists.
>
> Any thoughts?
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
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