Re: Hardware suggestions

<FONT face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size=2><div>Hi list members,<br><br>I have a question regarding hardware issues for a SDI (Spatial data infrastructure). It will consist of PostgreSQL with PostGIS and a UMN Mapserver/pmapper set up.<br>At our institute we are currently establishing a small GIS working group. The data storage for vector data should be the central PostGIS system. Raster data will be held in file system.<br>Mostly the users are accessing the data base in read only mode. From the client side there is not much write access this only will be done by the admin of the system to load new datasets. A prototype is currently running on an old desktop pc with ubuntu dapper - not very powerfull, of course!<br>We have about 10000 &#8364; to spend for a new server including the storage. Do you have any recommendations for us?<br>I have read a lot of introductions to tune up PostgreSQL systems. Since I don't have the possibility to tune up the soft parameters like cache, mem sizes etc., I wondered about the hardware. Most things were about the I/O of harddisks, RAM and file system. Is the filesystem that relevant? Because wo want to stay at Ubuntu because of the software support, espacially for the GIS-Systems. I think we need at least about 300-500Gb for storage and the server you get for this price are about two dualcore 2.0 - 2.8 GHz Opterons.<br>Do you have any suggestions for the hardware of a spatial data base in that pricing category?<br><br>Thanks in advance and greetings from Luxembourg,<br>Christian<br></div></FONT>

> At our institute we are currently establishing a small GIS working group.
> The data storage for vector data should be the central PostGIS system.
> Raster data will be held in file system.
> Mostly the users are accessing the data base in read only mode. From the
> client side there is not much write access this only will be done by the
> admin of the system to load new datasets. A prototype is currently running
> on an old desktop pc with ubuntu dapper - not very powerfull, of course!
> We have about 10000 € to spend for a new server including the storage. Do
> you have any recommendations for us?

When it comes to server-hardware I'd go for intel's dual-core
(woodcrest) or quad-core. They seem to perform better atm. compared to
opterons.

--
regards
Claus

When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.

Shakespeare

christian(dot)braun(at)tudor(dot)lu writes:

> sizes etc., I wondered about the hardware. Most things were about the I/O
> of harddisks, RAM and file system. Is the filesystem that relevant?
> Because wo want to stay at Ubuntu because of the software support,
> espacially for the GIS-Systems. I think we need at least about 300-500Gb
> for storage and the server you get for this price are about two dualcore
> 2.0 - 2.8 GHz Opterons.

I would suggest 8GB of RAM, 4 500GB (Seagate) drives in RAID10, a dual
core CPU (AMD or Dual Core) and 3ware or Areca controller.

If you don't need a 1U case and you can use a tower case you should be able
to get those specs within your budget.

christian(dot)braun(at)tudor(dot)lu wrote:
> Hi list members,
>
> I have a question regarding hardware issues for a SDI (Spatial data
> infrastructure). It will consist of PostgreSQL with PostGIS and a UMN
> Mapserver/pmapper set up.
> At our institute we are currently establishing a small GIS working
> group. The data storage for vector data should be the central PostGIS
> system. Raster data will be held in file system.
> Mostly the users are accessing the data base in read only mode. From
> the client side there is not much write access this only will be done
> by the admin of the system to load new datasets. A prototype is
> currently running on an old desktop pc with ubuntu dapper - not very
> powerfull, of course!
> We have about 10000 € to spend for a new server including the storage.
> Do you have any recommendations for us?
> I have read a lot of introductions to tune up PostgreSQL systems.
> Since I don't have the possibility to tune up the soft parameters like
> cache, mem sizes etc., I wondered about the hardware. Most things were
> about the I/O of harddisks, RAM and file system. Is the filesystem
> that relevant? Because wo want to stay at Ubuntu because of the
> software support, espacially for the GIS-Systems. I think we need at
> least about 300-500Gb for storage and the server you get for this
> price are about two dualcore 2.0 - 2.8 GHz Opterons.
> Do you have any suggestions for the hardware of a spatial data base in
> that pricing category?

Pay as much attention to your disk subsystem as to your CPU / memory
setup. Look at RAID-5 or RAID-10 depending on which is faster for your
setup. While RAID-10 is faster for a system seeing plenty of updates,
and a bit more resiliant to drive failure, RAID-5 can give you a lot of
storage and very good read performance, so it works well for reporting /
warehousing setups.

It might well be that a large RAID-10 with software RAID is a good
choice for what you're doing, since it gets good read performance and is
pretty cheap to implement. If you're going to be doing updates a lot,
then look at a battery backed caching controller.

Memory is a big deal. As much as you can reasonably afford to throw at
the system.

The file system can make a small to moderate impact on performance. Some
loads are favored by JFS, others by XFS, and still others by ext2 for
the data portion (only the pg_xlog needs to be on ext3 meta journaling only)

Scott Marlowe writes:

> and a bit more resiliant to drive failure, RAID-5 can give you a lot of
> storage and very good read performance, so it works well for reporting /

New controllers now also have Raid 6, which from the few reports I have seen
seems to have a good compromise of performance and space.

Francisco Reyes wrote:
> Scott Marlowe writes:
>
>> and a bit more resiliant to drive failure, RAID-5 can give you a lot
>> of storage and very good read performance, so it works well for
>> reporting /
>
> New controllers now also have Raid 6, which from the few reports I
> have seen seems to have a good compromise of performance and space.
>

Very true. And if they've gone to the trouble of implementing RAID-6,
they're usually at least halfway decent controllers.

On Thu, 21 Jun 2007, Scott Marlowe wrote:

> And if they've gone to the trouble of implementing RAID-6, they're
> usually at least halfway decent controllers.

Unfortunately the existance of the RAID-6 capable Adaptec 2820SA proves
this isn't always the case.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD

Greg Smith writes:

> Unfortunately the existance of the RAID-6 capable Adaptec 2820SA proves
> this isn't always the case.

For sata 3ware and Areca seem to perform well with raid 6 (from the few
posts I have read on the subject).

Don't know of SCSI controllers though.