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Disk Fills Up and fsck "Compresses" it
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* Disk Fills Up and fsck "Compresses" it
@ 2007-05-15 20:18  Y Sidhu <ysidhu@gmail.com>
  0 siblings, 1 reply; 5+ messages in thread

From: Y Sidhu @ 2007-05-15 20:18 UTC (permalink / raw)
  To: pgsql-performance

Anyone seen PG filling up a 66 GB partition from say 40-ish percentage to
60-ish percentage in a manner of minutes. When I run a 'fsck' the disk usage
comes down to 40-ish percentage. That's about 10+ GB's variance.

This is a FreeBSD 6.2 RC2, 4GB memory, Xeon 3.2 GHz '4' of the '8' CPUs in
use - dual cpu, dual core with HTT turned off in the sense that the other 4
cpu's have been masked out. The drive is a Western Digital 70 GB SATA.

-- 
Yudhvir Singh Sidhu
408 375 3134 cell

^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: Disk Fills Up and fsck "Compresses" it
@ 2007-05-15 23:41  Jim C. Nasby <decibel@decibel.org>
  parent: Y Sidhu <ysidhu@gmail.com>
  0 siblings, 1 reply; 5+ messages in thread

From: Jim C. Nasby @ 2007-05-15 23:41 UTC (permalink / raw)
  To: Y Sidhu <ysidhu@gmail.com>; +Cc: pgsql-performance

I'm guessing you're seeing the affect of softupdates. With those enabled
it can take some time before the space freed by a delete will actually
show up as available.

On Tue, May 15, 2007 at 01:18:42PM -0700, Y Sidhu wrote:
> Anyone seen PG filling up a 66 GB partition from say 40-ish percentage to
> 60-ish percentage in a manner of minutes. When I run a 'fsck' the disk usage
> comes down to 40-ish percentage. That's about 10+ GB's variance.
> 
> This is a FreeBSD 6.2 RC2, 4GB memory, Xeon 3.2 GHz '4' of the '8' CPUs in
> use - dual cpu, dual core with HTT turned off in the sense that the other 4
> cpu's have been masked out. The drive is a Western Digital 70 GB SATA.
> 
> -- 
> Yudhvir Singh Sidhu
> 408 375 3134 cell

-- 
Jim Nasby                                      decibel@decibel.org
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: Disk Fills Up and fsck "Compresses" it
@ 2007-05-16 15:21  Y Sidhu <ysidhu@gmail.com>
  parent: Jim C. Nasby <decibel@decibel.org>
  0 siblings, 1 reply; 5+ messages in thread

From: Y Sidhu @ 2007-05-16 15:21 UTC (permalink / raw)
  To: Jim C. Nasby <decibel@decibel.org>; +Cc: pgsql-performance

What do you mean by "softupdates?" Is that a parameter in what I am guessing
is the conf file?


Yudhvir

On 5/15/07, Jim C. Nasby <decibel@decibel.org> wrote:
>
> I'm guessing you're seeing the affect of softupdates. With those enabled
> it can take some time before the space freed by a delete will actually
> show up as available.
>
> On Tue, May 15, 2007 at 01:18:42PM -0700, Y Sidhu wrote:
> > Anyone seen PG filling up a 66 GB partition from say 40-ish percentage
> to
> > 60-ish percentage in a manner of minutes. When I run a 'fsck' the disk
> usage
> > comes down to 40-ish percentage. That's about 10+ GB's variance.
> >
> > This is a FreeBSD 6.2 RC2, 4GB memory, Xeon 3.2 GHz '4' of the '8' CPUs
> in
> > use - dual cpu, dual core with HTT turned off in the sense that the
> other 4
> > cpu's have been masked out. The drive is a Western Digital 70 GB SATA.
> >
> > --
> > Yudhvir Singh Sidhu
> > 408 375 3134 cell
>
> --
> Jim Nasby                                      decibel@decibel.org
> EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)
>



-- 
Yudhvir Singh Sidhu
408 375 3134 cell

^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: Disk Fills Up and fsck "Compresses" it
@ 2007-05-16 15:51  Jim C. Nasby <decibel@decibel.org>
  parent: Y Sidhu <ysidhu@gmail.com>
  0 siblings, 1 reply; 5+ messages in thread

From: Jim C. Nasby @ 2007-05-16 15:51 UTC (permalink / raw)
  To: Y Sidhu <ysidhu@gmail.com>; +Cc: pgsql-performance

No, it's part of FreeBSD's UFS. google FreeBSD softupdates and you
should get plenty of info.

As I said, it's probably not worth worrying about.

On Wed, May 16, 2007 at 08:21:23AM -0700, Y Sidhu wrote:
> What do you mean by "softupdates?" Is that a parameter in what I am guessing
> is the conf file?
-- 
Jim Nasby                                      decibel@decibel.org
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: Disk Fills Up and fsck "Compresses" it
@ 2007-05-16 23:28  Mark Kirkwood <markir@paradise.net.nz>
  parent: Jim C. Nasby <decibel@decibel.org>
  0 siblings, 0 replies; 5+ messages in thread

From: Mark Kirkwood @ 2007-05-16 23:28 UTC (permalink / raw)
  To: Jim C. Nasby <decibel@decibel.org>; Y Sidhu <ysidhu@gmail.com>; +Cc: pgsql-performance

Jim C. Nasby wrote:
> No, it's part of FreeBSD's UFS. google FreeBSD softupdates and you
> should get plenty of info.
> 
> As I said, it's probably not worth worrying about.
> 
> On Wed, May 16, 2007 at 08:21:23AM -0700, Y Sidhu wrote:
>> What do you mean by "softupdates?" Is that a parameter in what I am guessing
>> is the conf file?

Here is quite a good article on the interaction of fsck and softupdates 
in FreeBSD:

http://www.usenix.org/publications/library/proceedings/bsdcon02/mckusick/mckusick_html/index.html

Having said that, it seems to talk about space lost by unreferenced 
blocks and inodes is the context of panic or power outage, as opposed to 
normal softupdate operation (unless I'm missing something...)

Cheers

Mark



^ permalink  raw  reply  [nested|flat] 5+ messages in thread


end of thread, other threads:[~2007-05-16 23:28 UTC | newest]

Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2007-05-15 20:18 Disk Fills Up and fsck "Compresses" it Y Sidhu <ysidhu@gmail.com>
2007-05-15 23:41 ` Jim C. Nasby <decibel@decibel.org>
2007-05-16 15:21   ` Y Sidhu <ysidhu@gmail.com>
2007-05-16 15:51     ` Jim C. Nasby <decibel@decibel.org>
2007-05-16 23:28       ` Mark Kirkwood <markir@paradise.net.nz>

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