2000-11-21 17:34:11

by Roberto Fichera

[permalink] [raw]
Subject: Ext2 & Performances

Hi All,

I need to know if there are some differences, in performances, between
a ext2 filesystem in a 10Gb partition and another that reside in a 130Gb,
each one have 4Kb block size.

I'm configuring a Compaq ML350 2x800PIII, 1Gb RAM, 5x36Gb UWS3 RAID 5
with Smart Array 4300, as database SQL server. So I need to chose between a
single
partition of 130Gb or multiple small partitions, depending by the performances.

Thanks.


2000-11-21 18:30:49

by Jakob Oestergaard

[permalink] [raw]
Subject: Re: Ext2 & Performances

On Tue, Nov 21, 2000 at 05:58:58PM +0100, Roberto Fichera wrote:
> Hi All,
>
> I need to know if there are some differences, in performances, between
> a ext2 filesystem in a 10Gb partition and another that reside in a 130Gb,
> each one have 4Kb block size.
>
> I'm configuring a Compaq ML350 2x800PIII, 1Gb RAM, 5x36Gb UWS3 RAID 5
> with Smart Array 4300, as database SQL server. So I need to chose between a
> single
> partition of 130Gb or multiple small partitions, depending by the performances.

Does your database *require* a filesystem ? At least Oracle can do without,
but I don't know about others...

Usually, if you want performance, you let the database use the block device
without putting a filesystem on top of it.

You probably don't want a 130G ext2 if there is any chance that a power
surge etc. can cause the machine to reboot without umount()'ing the
filesystem. A fsck on a 130G filesystem is going to take a *long* time.

--
................................................................
: [email protected] : And I see the elder races, :
:.........................: putrid forms of man :
: Jakob ?stergaard : See him rise and claim the earth, :
: OZ9ABN : his downfall is at hand. :
:.........................:............{Konkhra}...............:

2000-11-21 18:51:53

by Roberto Fichera

[permalink] [raw]
Subject: Re: Ext2 & Performances

At 19.00 21/11/00 +0100, Jakob ?stergaard wrote:

>On Tue, Nov 21, 2000 at 05:58:58PM +0100, Roberto Fichera wrote:
> > Hi All,
> >
> > I need to know if there are some differences, in performances, between
> > a ext2 filesystem in a 10Gb partition and another that reside in a 130Gb,
> > each one have 4Kb block size.
> >
> > I'm configuring a Compaq ML350 2x800PIII, 1Gb RAM, 5x36Gb UWS3 RAID 5
> > with Smart Array 4300, as database SQL server. So I need to chose
> between a
> > single
> > partition of 130Gb or multiple small partitions, depending by the
> performances.
>
>Does your database *require* a filesystem ? At least Oracle can do without,
>but I don't know about others...

Currently I'm using PostgreSQL.

>Usually, if you want performance, you let the database use the block device
>without putting a filesystem on top of it.

Yes! I know! Oracle should be a good choice for that.

>You probably don't want a 130G ext2 if there is any chance that a power
>surge etc. can cause the machine to reboot without umount()'ing the
>filesystem. A fsck on a 130G filesystem is going to take a *long* time.

Yes! I know :-((!!! I'm looking for other fs that are journaled like ext3
or raiserfs
but I don't know which are a good choice for stability and performances.

2000-11-21 19:02:50

by Andreas Dilger

[permalink] [raw]
Subject: Re: Ext2 & Performances

Roberto Fichera writes:
> I'm configuring a Compaq ML350 2x800PIII, 1Gb RAM, 5x36Gb UWS3 RAID 5
> with Smart Array 4300, as database SQL server. So I need to chose
> between a single partition of 130Gb or multiple small partitions,
> depending by the performance.

It is usually better to have multiple small partitions for performance and
reliability, but this is more work to administer.

> Yes! I know :-((!!! I'm looking for other fs that are journaled like ext3
> or raiserfs but I don't know which are a good choice for stability and
> performances.

The current (0.0.5b) ext3 code is doing pretty good, and if you use
metadata-only journalling it is about as fast as ext2. I still wouldn't
use this on a production system where data loss is fatal, although I
have never had any data loss or filesystem corruption because of ext3.

Cheers, Andreas
--
Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto,
\ would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert

2000-11-21 19:06:21

by Aaron Sethman

[permalink] [raw]
Subject: Re: Ext2 & Performances

You might want to take a look at using reiserfs on the 130GB partition, as
its is journalled and doesn't need to be fsck'ed. Take a look a
http://devlinux.com/namesys/

Aaron

On Tue, 21 Nov 2000, Roberto Fichera wrote:

> At 19.00 21/11/00 +0100, Jakob ?stergaard wrote:
>
> >On Tue, Nov 21, 2000 at 05:58:58PM +0100, Roberto Fichera wrote:
> > > Hi All,
> > >
> > > I need to know if there are some differences, in performances, between
> > > a ext2 filesystem in a 10Gb partition and another that reside in a 130Gb,
> > > each one have 4Kb block size.
> > >
> > > I'm configuring a Compaq ML350 2x800PIII, 1Gb RAM, 5x36Gb UWS3 RAID 5
> > > with Smart Array 4300, as database SQL server. So I need to chose
> > between a
> > > single
> > > partition of 130Gb or multiple small partitions, depending by the
> > performances.
> >
> >Does your database *require* a filesystem ? At least Oracle can do without,
> >but I don't know about others...
>
> Currently I'm using PostgreSQL.
>
> >Usually, if you want performance, you let the database use the block device
> >without putting a filesystem on top of it.
>
> Yes! I know! Oracle should be a good choice for that.
>
> >You probably don't want a 130G ext2 if there is any chance that a power
> >surge etc. can cause the machine to reboot without umount()'ing the
> >filesystem. A fsck on a 130G filesystem is going to take a *long* time.
>
> Yes! I know :-((!!! I'm looking for other fs that are journaled like ext3
> or raiserfs
> but I don't know which are a good choice for stability and performances.
>
> -
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>
>

2000-11-22 07:58:52

by Eric W. Beiderman

[permalink] [raw]
Subject: Re: Ext2 & Performances

Aaron Sethman <[email protected]> writes:

> You might want to take a look at using reiserfs on the 130GB partition, as
> its is journalled and doesn't need to be fsck'ed.
No.

All journaling filesystems need to be fsck'ed.
A correctly operating one simply doesn't need to be fsck'ed because
of unexpected loss of operating system. Which brings greatly reduce
the probability. If an error is detected in the filesystem fsck is
still what you have to do to correct it.

Eric