New server spec

Matthew Joyce MJoyce at ccia.unsw.edu.au
Mon Apr 19 20:54:01 CDT 2004


Thanks, a very interesting post.

We are a small non-profit org, we do not have a DBA, so we have to
muddle through.
This db will be running PostgresSQL and will mostly be providing results
to searches.

There will be about 50 users, probably only 5 will be inputing new data,
most will be read only.

I've just spent some time reading up on PostgresSQL performance and as
with other DBs, optimum setup depends on how it is used.

So, more research needed.

I need to find a balance between cost and performance.  Sounds familier.




Matt Joyce
Children's Cancer Institute Australia
http://www.ccia.org.au


> -----Original Message-----
> From: Paul [mailto:paul at kbs.net.au] 
> Sent: Monday, 19 April 2004 6:25 PM
> To: Matthew Joyce
> Cc: linux-poweredge at dell.com
> Subject: Re: New server spec
> 
> 
> 
> Hi Matthew,
> 
> Just some ideas also:
> 
> You should consider what work you database will do and what 
> load. If it's lots of writes and only a few reads then you 
> should stay away from RAID5 and lean towards RAID10. If its 
> just a few reads and a few writes then mirroring should be 
> ok. Consider the use of database (reads vs writes) and 
> freqency (number of active users) to reach a desired RAID 
> level. There are many advantages and disadvantages for each 
> RAID level especially when you involve hardware RAID, you 
> should consult a DBA or at least have your config review by 
> your DBA or database guru in the company. Also U160 is old, 
> you should be after U320. You can't buy new U160 drives, only 
> Ultra320 scsi. Suppliers may have old stock of Ultra160 
> disks, Controllers etc but anything new is Ultra320 as far as 
> I know. I could be wrong but this is my experiences with DB's 
> and SCSI equipment. Dell's U160 is perc3d(x) and the U320 is 
> perc4d(x). The perc3 is adaptec AACRAID and perc4 is LSI 
> logic megaraid.
> 
> Also depending on database and usage you may wany seperate 
> spindels for things like redo logs, archive logs, database 
> files etc.. Database's like Oracle, MSSql Server have 
> seperate block files for each main component so you can 
> stripe and split them onto seperate blocks. Each having their 
> own usage frequency but equally as important. Example in 
> Oracle you are recommended to have a mirror set for each 
> group of files. Redo, Archive, Tablespace, OS + Oracle files, 
> Otherparts so it looks like this
> 
> /dev/sda1        2 x 36gb mirror   OS + Oracle
> /dev/sdb1        2 x 36gb mirror    Tablespace Files (main .dfb files,
> data01, data02 etc...)
> /dev/sdc1        2 x 36gb mirror     Redo Logs (redo01 redo02 
> redo03 files)
> /dev/sdd1        2 x 36gb mirror     Archive FIles (arch logs 
> for restoring)
> /dev/sde1        2 x 36gb mirror     Other various oracle 
> .dbf files (cant
> remember exactly)
> 
> This is so that writes to the redo logs which occur whenever 
> an insert happens are quick and don't slow down data01 disk 
> access. Archive files on seperate spindle so that when your 
> database spits out a redo segment as an archive log its on 
> seperate disks that dont hamper redo log or data01 data02 access.
> 
> Of course you should consult your DBA bits of my example 
> could be slighty incorrect or wrong.  Size as in MB or GB 
> won't affect your RAID config that much but more so access 
> patterns and usage. If your database is say 450MB in total 
> but you have 13 inserts/sec for 24x7 then you'll need 
> something like the above, nice fast, redudnant and nothing 
> gets slowed down. Whereas if your database is 45GB and you 
> have 1 insert an hour and 10 selects per second then a single 
> 73 x 2 mirror set should be fine. If your looking at mysql 
> then the above "blocks" don't apply its only highend such as 
> Oracle or MS-SQL server, sybase etc that have seperate blocks 
> that should be kept on seperate mirror sets. And further if 
> you have the funding the mirror sets on seperate scsi 
> channels and controllers to even reduce futher bottlenecks in 
> the database. Hope this helps
> 
> Regards,
> Paul
> 
> ----- Original Message ----- 
> From: "Matthew Joyce" <MJoyce at ccia.unsw.edu.au>
> Cc: <linux-poweredge at dell.com>
> Sent: Monday, April 19, 2004 5:24 PM
> Subject: RE: New server spec
> 
> 
> >
> > >
> > > > Sorry to reply to my own post, but I am now considering the 
> > > > following...
> > >
> > > > PE2650, 3Ghz, 1Gb, 2 x 73GB SCSI
> > > > RedHat Enterprise Server 3
> > >
> > > how busy is this server ? you may want to add more 
> drives, e.g 2 * 
> > > 73G for your OS and 2 * 73G for your database, both running RAID1.
> > >
> > > you may also want to buy more than one CPU as this would 
> assist with 
> > > a web and database application both running.
> > >
> >
> > It is not going to be furiously busy, it's an internal app, 
> less then 
> > 30gb db / 50user for the first 2 years.
> >
> > I though 2x73gb RAID1, would be fine for this and if it 
> gets bigger I 
> > can add drives and move to RAID5.  Originally it was going to be a 
> > pe1750, but as the price is not much different I think it will be a 
> > pe2650.
> >
> > That said with the extra drive bays, perhaps 3x36 will be more 
> > suitable.
> >
> >
> > > >> I'm looking to buy a dell server to run Redhat 9 (our 
> developers 
> > > >> preferred platform for app). Which version of RH do I need
> > > to use for
> > > >> a database/web server ? Professional ?
> > > >> I'm thinking a PE1750, with mirrored 36gb drives, 3ghz, 1gb.
> > >
> > >
> > > You can probably get by fine with RHEL3/ES.  Have you 
> determined if 
> > > you need support or not ? (ES/Basic or ES/Standard)
> >
> > I'm hoping I will not need support, I think it would be prudent 
> > though, I have a budget to stick too, so it will depend on price. 
> > Sadly.
> >
> >
> > >
> > > > Probably with an adaptec U160 and some sort of DLT drive.
> > >
> > > What is the U160 card for ? and why DLT ? it appears 
> you've chosen 
> > > the technology already.. if you have a specific backup 
> requirement 
> > > you may want to consider LTO as an alternative.  
> whichever one you 
> > > buy from dell they should be able to supply the appropriate card.
> > >
> >
> > U160 - I have had good experieces with this in the past
> > DLT - cost and we already have existing investment in dlt 
> > drives/tapes.
> >
> >
> > > regards,
> > >
> > > -jason
> > >
> >
> >
> > Thanks
> >
> > Matt
> >
> > _______________________________________________
> > Linux-PowerEdge mailing list
> > Linux-PowerEdge at dell.com 
> > http://lists.us.dell.com/mailman/listinfo/linux-poweredge
> > Please read the FAQ at http://lists.us.dell.com/faq or 
> search the list
> archives at http://lists.us.dell.com/htdig/
> >
> 
> 




More information about the Linux-PowerEdge mailing list