Hardware setup advice for my db.

[bazz]

Hi,

I am asking for advice on how to set up a multi server db. The db content will relate to several countries and I need to be able to avoid 'boundaries' so that info for a office on the german - french border, will be able to include info on both France and Germany.

I have been told that I need to break up the data across multple servers so that I stay within processor capabilities and keep the thing running efficiently.

Can any of you offer tips on how to do this. I have been advised to consider two+ hard disks running on RAID so that they each back each other up.

I need:

1. guaranteed 24 hr uptime
2. guaranteed no loss of data
3. to be able efficiently, to show data from more than one hdd/db.
4. to manage 2000+ email accounts and plesk doesn't do that.
5. be able to show info from across the different db's/hdd's.

Any of you know of an alternative which can cope with thousands of email accounts?

bazz

[oracleguy]

RAID is not a backup solution, it is a fault tolerance solution. It can protect you against hardware failures but not software ones. File system corruption can happen just as easily on a RAID array as a single hard drive.

I think a NAS (Network Attached Storage) is what you are looking for. Multiple servers can pull from it and you can get one with RAID 6. And you will need two, another one to keep off site in case the first one is destroyed in a disaster (fire, bomb, flood, etc.) and as a backup in general. You'll need two UPSes for the NAS, one for each power supplies (assuming it has redundant power supplies) and then a generator that powers both of those. And then of course emergency power for the servers. You'll need to a dedicated redundant link between the two data centers with fail over to the backup servers in case the primary ones go down. Make sure the SLA with your hardware vendor is 24x7 with no more than a 4 hour response time.

To truly get number 1 and 2 it will not be cheap by any means. It might sound over the top but preventing even the chance of any sort of data loss takes a lot of measures. It really depends just how critical this data is. If you can in reality stand to lose the last 12-24 hours of data or be down for a few hours due to a power outage or network failure, then it doesn't have to be so extreme.

[bazz]

oracleguy, thank you.

So, would I put the whole db onto NAS and then have a server for each area/region, that site visitors come from so that those servers channel the traffic, or, would I put the db onto NAS and have indexes for it ojn each of the other servers?

bazz

[oracleguy]

That would depend on how you have your network setup, are all your regions on the same WAN?

[bazz]

All the servers will be operated from the same single datacentre.
The db data is to be accessible by all users via browser.

bazz

[oracleguy]

Ok, well then what you could do is have your load balancing cluster of database servers and they all store their data on the NAS (so you have a centralized data storage location). It has been a few years since I've worked with clustering db servers so I'm a little sketchy on the specifics software wise but that is the direction I'd recommend looking.

And advantage of a cluster over using a server for a specific region is that if a server goes down, the other servers just have to do more work is all instead of that db server going inaccessible

[bazz]

Thnaks, it seems to becoming clearer now.

So if I have the db hosted on NAS and have multiple RAID servers getting the info from it as required, is it also possible to use each server in the array, for the purposes of running clients mailboxes or website domains? if so, I could have plesk on each one and, operations-wise, keep working as I am now.

bazz

[oracleguy]

I don't see any reason why you couldn't run web servers on it as well. I know it all sounds kinda mysterious but hopefully I've at least given you some good stuff to investigate with.

[bazz]

Yes, indeed.

I shall google the subject some more now since I understand what a NAS is and (thanks to you) now understand RAID. Yes, you're right; it is mysterious and I am gradually getting over it. :)

Just one more question, if I may; Can the db be backed up constantly on a NAS or would I need to have two running in parallel where one is a mirror of the other and, ready to become live if the first NAS fails?

bazz