building a sata server

llatsni

Hi guys, a bit of a long one:

A client of mine will be moving offices soon, and i prompted them that it would be an excellent opportunity to do things right in terms of a "proper" network & server setup.

I want to build a high spec reliable server and i was thinking (basically) the following:
- Dual XEON
- 2GB ECC
- 4-6 10k Raptor SATA in some RAID combo
- Redundant PSU

THE NUT OF THE PROBLEM:
My problem is that I'm finding it very diffiucult to get info about hot-swappable SATA RAID systems.
My idea was that I could set up a RAID 5 rig with the drives in hot swappable bays. I was hoping that it would be possible (through hardware) to have 1 drive designated as a backup drive. My client would just simply pull out this drive each evening and replace it the following morning (or preferably have 2 drives that alternate). My wish is that there is some way of ensuring a reliable rebuild of the data on that drive each day (or every other day if 2 drives), that has a minimal penalty on performance.

Does any of that make sense?

Basically I'm sick of tape drives, and anyway I wouldnt trust this client that they would bother with them regularly - a removable HD seems WAY simpler from that regard.

Any help or thoughts appreciated.

Rew

WHat your talking about wont work for RAID 5 anyway. RAID 5 stripes data accross all drives so no one drive has a master copy of the data. So if you pull out a disk to be a backup it will only contain striped data which will be **** all good to you.

RAID 1 mirrors data so if you have two drives one is a perfect copy of the other.

RAID isnt really designed for pulling out a daily backup its ment to stop the machine falling over in the event of a disk failure.

You should look at a good tape solution if you ask me...

How much data has to be backed up daily?

llatsni

Thanks REW, I was a bit sleepy this morning and my currents thoughts are lying somewhere around this:

4x 10k Raptor 76GB in raid 10 = 152GB array in one of these

2x Hitachi Deskstar 7K250 (250 GB SATA) in removable trays with some backup software running that updates/syncronises files in the OS when 1 of these disks is present

Any suggestions for the removable backup?

Rew

Whats the OS?

So the 250GB disks will be your removable backups or are you still looking for something else?

What is the data being backed up? How much is there?

Have you looked at the wear and tear issues with hotswaping disks on a daily basis?

llatsni

Thanks again Rew for your interest...

the idea is that the 250gb disks would be the backup, the data is:

- Databases
- email
- office docs etc.

i have no idea where to look to find out about wear and tear - i doubt its any worse than DLT's???

also i was thinking about having the os (prob Win2003) on a 2 disk RAID 1 array

Is this all a bit mad?

Rew

Im not sure if there are long term issuse for hotswaping disks on a daily basis but its somthing you should look in to (imagine you need the backup and the disk is ****ed...)

You will need to get each app to do a dump of its data to the backup disk (scripting sheduluing of some kind) Your better off just dumping the data as opposed to copying the entire DB install or similar esp with Windows. Backing up file shares is easier. You should compress up each backup witha date in the fiile name. Backups should be tested once a month or so. Have you decided where the backup will be stored when its not in the machine?

What procedure are you going to use? 3 of those 250 gig disks (2 in the machine at anyone time and the 3rd off site?)

It is a bit mad but doable. Id be afraid that hotswaping the disks might overly stress them leading to failures. Hard disks aren't known for there stability after a lot of handling either. WIndows *should* cope ok with all thje hotswaping.

OS should def be on a RAID 1 setup no general data on the OS disks, that will save your arse some day.

llatsni

My fiend suggested this as a possible OS, that supports cool raid backup features:

http://net-itech.com/products/nitix.php

it incrementally backs up to a chosen disk every 15 min

and it runs off a cd or IDE chip!

BigEejit

Raid was primarily designed for reliability, even if you got a raid 5 group working nicely (where any drive could fail and the data could be regenerated from other drives - see here ) a data rebuild would take hours if not days and your performance would be crap during that period.

I also would not trust a single server with all the day to day documents used by your business, have a backup somewhere else in the building - you definitely will be glad of it some day .... the backup does not have to be a monster of a machine like the main one, just be good enough to hold you over ..... of course there is no use having a backup machine if you havent got the right data on it, so you'll have to get some batch running that will copy over changed files during quiet periods or something to do it on the fly.

Dont put all your eggs in one basket - see if you can get online offsite storage set up ... moving drives regularly is a disaster waiting to happen ... even if you were using one of these .... I'm positive you will kill the drive within the year ... and of course murphys law would come into effect straight away if it did fail - your servers at work would both melt and get viruses and get hit by lightening and have cups of coffee spilt into them at EXACTLY that time .... you'll be a quivering wreck while your boss gives you a kick in the hole out the door

Mac daddy

I can ask why are you getting SATA hdd and Not SCSI and a Array controller.

As for the Hotswapping of the drive every night :rolleyes: bad idea. damage pins on the drive and the drive cage backplane.

I would still keep a tape drive as backup- you can get library's who do all the swapping for you so the client won't have to do anything.depending on software used.
Instead of a DLT drive you could look into LTO drives much faster.

llatsni

This is a SMALL business, that happens to have critical data. Money is to a certain extent an issue. i.e. they wont spend goober loads of it.
My angle is that it would cost them significantly more to recreate the data than to adaquately back-it-up in the first place.

DLT's are expensive (and in my experience NOT very reliable AT ALL), LTO's are usually out of the SMB league.

My friend who recommended the NITIX thing now swears by the HDD backup. He has installed quite a few of them and recons they are very reliable compared to tapes. (I just had a 1/2 hour conversation with him).

He's coming over to demo it, i'll let you know what i think.

Mac daddy

Okay that is fair enough but still would not go with the Hotswapping Hdd because of the Pins will get worn and damaged worse yet could drop Hdd- If you drop a tape it is fine.
How long is it going to take you to back up the data to HDD?

Mutant_Fruit

Firstly, why get raptors? Are you doing intensive disk access like video editing? You'd be better off getting cheaper disks, and running seperate raid1's in two totally seperate computers.

What i would do is have your main computer, running a raid1 (maybe raid 5). That would be quite safe data-wise, providing no-one drops a hammer on the box.

A second box, which contains only an ethernet card and a two HD's should be set up somewhere completely seperate in the building. This can be monitored and accessed cia Radmin, or any old remote access software, so you need no keyboard/monitor etc on the second box.

This box would have 5400rpm drives, as this would be a data-dump, where every night (or few hours, depending on your needs) the data would be backed up there as needed. The 5400rpm drives spin slower, so generate less heat, and also should hopefully live longer. Ideally they would be in raid1 or 5.

Then, once a month, or more, you should back the data up to an offsite area, maybe using the existing tapes. hotswapping is not really the best thing to be doing, it shortens the lifespan of the drives, and makes the pins more prone to damage.

Col_Loki

If you are hot swapping then what about a USB option for backup? Id agree with the guys about the wear and tear issues and the hard drives are prone to failure if not handled correctly (ie kept away from static etc etc). The USB enclosure means its easy to plug in and out, and the HD is protected.

http://www.komplett.ie/k/kl.asp?bn=10098

Also on the backup thing, thats a great idea of having a small system stored in another room for backup. It can be a cheap system ........ and you can make a simple batch file and use windows event manager to use it to back up everything at say 1am (when its not in use). Its cost effective and a good idea IMO.

It must require alot of processing power if your putting Xeons into it, a cheaper option would be AMD MP's which is a very stable quite powerfull solution either. Ohh and of coarse opterons......

PS Just on a side note, Xeons are going 800mhz FSB pretty soon so it might be a good idea to get a board that supports them for upgrades (Asus PC-DL should do it with BIOS update, IWill DH800 already does). Also opterons are supposed to go dual core arround the start of 2005 (dont know how accurate the date is - especially with AMD).