Huge 1.2TB partition

Huge 1.2TB partition

[Stas Nikiforov]

Hi,
I have RAID 5 6x250 SATA storage.
Is it a good idea to have one huge partition
or it is better to split it on smaller logical drives and then use LVM,
for example?

In any way, what is a preferred filesystem for this storage?
I plan to use it as a mass storage for CFD results.

Thanks in advance,
Stas.
-- 
Mr. Nikiforov Stanislav

Intsitute of Theoretical and Applied Mechanics
4/1, Institutskaya str., 
Novosibirsk, 930090, 
Russia

Voice: +7 3832 343163
E-mail: stas@itam.nsc.ru  

Re: [Rocks-Discuss]Huge 1.2TB partition

[Joe Landman]

Hi Stas:

  There is a bug in 2.4 kernels with SCSI  that limits you to 1 TB or 
less.  The folks at 3ware have a patch for it (it is fixing a signed int 
to be an unsigned int in sd.c).  Without this patch, you are going to 
have trouble making a single large volume.  You could create 2 volumes 
and LVM or MD them together.  This would be hard to do with the number 
of disks you have as a RAID5.

  What is best is usually dictated by your use case.  For large storage 
purposes, one volume might be better.

Joe

Stas Nikiforov wrote:

>Hi,
>I have RAID 5 6x250 SATA storage.
>Is it a good idea to have one huge partition
>or it is better to split it on smaller logical drives and then use LVM,
>for example?
>
>In any way, what is a preferred filesystem for this storage?
>I plan to use it as a mass storage for CFD results.
>
>Thanks in advance,
>Stas.
>  
>

-- 
Joseph Landman, Ph.D
Scalable Informatics LLC,
email: landman@scalableinformatics.com
web  : http://scalableinformatics.com
phone: +1 734 612 4615

Re: [Rocks-Discuss]Huge 1.2TB partition

[David]

On Fri, 2004-09-24 at 17:45, Joe Landman wrote:
> Hi Stas:
> 
>   There is a bug in 2.4 kernels with SCSI  that limits you to 1 TB or 
> less.  The folks at 3ware have a patch for it (it is fixing a signed int 
> to be an unsigned int in sd.c).  Without this patch, you are going to 
> have trouble making a single large volume.  You could create 2 volumes 
> and LVM or MD them together.  This would be hard to do with the number 
> of disks you have as a RAID5.
> 
>   What is best is usually dictated by your use case.  For large storage 
> purposes, one volume might be better.
> 
The RHEL kernels are patched for this, I have two 3ware arrays with 1.2
and 1.5 Tb respectively. However RHEL has a nasty bug on these arrays as
noted before. I'd go for Fedora 2.

> Joe
> 
> Stas Nikiforov wrote:
> 
> >Hi,
> >I have RAID 5 6x250 SATA storage.
> >Is it a good idea to have one huge partition
> >or it is better to split it on smaller logical drives and then use LVM,
> >for example?
> >
> >In any way, what is a preferred filesystem for this storage?
> >I plan to use it as a mass storage for CFD results.
> >
> >Thanks in advance,
> >Stas.
> >  
> >
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel@xray.bmc.uu.se	spoel@gromacs.org   http://xray.bmc.uu.se/~spoel
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Re: Huge 1.2TB partition

[Mark Overmeer]

* Stas Nikiforov (stas@itam.nsc.ru) [040924 11:50]:
> I have RAID 5 6x250 SATA storage.
> Is it a good idea to have one huge partition
> or it is better to split it on smaller logical drives and then use LVM,
> for example?
> 
> In any way, what is a preferred filesystem for this storage?
> I plan to use it as a mass storage for CFD results.

I run a disk-set of 4x250 SATA with an Adaptec 2410SA and
      a disk-set of 8x250 SATA with an Adaptec 2810SA.

In both cases, I have a small disk aside, which I use for the OS, log-
files and such.  The array is dedicated to my data: satellite images.

Usually, having one partition is best,  certainly with a file-system
which is tuned on large disk-sets.  I choose XFS, which is capable of
handing much larger partitions.  It runs currently on SuSE9.0 with
recent 2.6 kernels.

My selection is not based on performance tests: the I/O bandwidth of
the PCI-bus is my bottleneck.  But in my case counts: as long as it
is faster than a tape-archive..... and cheap
-- 
               MarkOv

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