SATA Raid question

itdaddy

Hey guys

I want to put bigger drives in our server. I have never done this but
in theory shouldn't it work?

Okay right now we have 4 300 GB sata drives in our server.
If I wanted to increase the size of the raid set can't I just
start adding 1 drive at a time until it rebuilds itself on all four new
500GB drives or 4 1TB drives?? I mean replace 1 at a time
and then I would have to resize them with a utility right?
once they are all replaced and rebuilt I would have to use windows 2003
disk management to resize them. How risky is this? just curious?
And you can bet I would make a backup first of the OS on drive
C and all the data on Drive D first. Maybe back it up twice.
just to make sure.

And from a technician's point of view working with SAS and SATA whatis the difference?
I mean I love that sata you can shut the machine off and change out
the SATA raid housing and replace it and turn it back on with the same drives
and it auto detects it right away. can you do that with sas? what is the difference
from a server engineers perspective. The mechanics of it not the How it transfers data
and bit for bite speach. I mean from the tech's view replacing drives in servers.
what is the difference between sas and sata. they even look the same dont they?
I have not seen SAS before I have seen sata and scsci do they look the same as sata?
thanks

earweed

First off if you're using Server 2003 shouldn't this be in the MCSE section?
That aside we'll need more info. Is this with a software or hardware RAID and what RAID are you using?
You may just be best off backing up what you have, replace all the HDDs and configure your RAID array and restore the Backed up Drives. Again this could be affected by what type of RAID you're running.

hypnotoad

It might work, but it sounds like it could be dangerous for the data and the users...those drive rebuilds can take a long time (days, depending on the hardware), and in that time if another drive fails you're outta luck. Plus performance will probably take a significant hit.

remyforbes777

SAS drives are typically smaller in size than SATA or SCSI drives.
Serial attached SCSI - Wikipedia, the free encyclopedia

It goes on to say that SATA drives can be connected to SAS backplanes but not vice versa.

I am not sure that your solution will work. If you begin sticking larger drives in there it will size those drives accordingly so if there are 300 GB drives in there now and you begin sticking 1TB drives in there it will size those drives as 300GB drives ignoring the extra space. Best thing to do is what earweed suggested. Back up all your data and OS, change out the drives, set up a bigger logical drive in the RAID and go from there.

bertieb

This is likely to be dependant on the hardware in use, i.e. server manufacturer/raid controller/disk firmware. I used to do something similar around 10 years ago with mighty 2GB SCSI disks (upgrading to 4.2GB) in RAID1/5 situations using HP NetRAID controllers (!) and whilst it was not officially supported by HP it did actually work.

That said, I would suggest it's a very risky strategy and I'd hazard a guess that the vendor would not support this method. As Remy said, an awful lot of RAID controllers out there will restrict the size of the replacement to the smallest disk in the array and even if they are all replaced you may well find you can't see the remaining space to be able to expand them at the RAID controller level.

Without checking with the vendor, I'd generally agree with the others in that you should consider this a major server upgrade and plan accordingly (fully document and backup data/configuration, arrange maintenance window, replace drives, reinstall OS and restore data etc)

There are lots of articles out there on the t'internet detailing the overall differences between SAS/SATA etc, e.g.
The Difference Between SCSI, ATA, SAS and SATA - Webopedia.com

Asif Dasl

bertieb wrote: »

I would suggest it's a very risky strategy and I'd hazard a guess that the vendor would not support this method. As Remy said, an awful lot of RAID controllers out there will restrict the size of the replacement to the smallest disk in the array and even if they are all replaced you may well find you can't see the remaining space to be able to expand them at the RAID controller level.

+1

The only RAID device I have seen which can do this is a Drobo. Plus, Server 2003 cannot extend a volume beyond its inital capacity.

bertieb

Asif Dasl wrote: »

Server 2003 cannot extend a volume beyond its inital capacity.

Actually, you can extend a data volume in 2003 (non system or boot) using the inbuilt diskpart utility
How to extend a data volume in Windows Server 2003, in Windows XP, in Windows 2000, and in Windows Server 2008

There are various third party tools that can increase the system partition on 2003, some are better (and more reliable) than others

Asif Dasl

I must try that, I usually use a Partition Magic CD though.

itdaddy

thanks guys. yeah I am going to back it up.
i can see it is a major process. wow you would think it would be that easy. to upgrade to a larger drive and all but yeah I can see it building a 300 GB drive again on top of the 1 TB drive just thought maybe I could change them all out and then resize. They are sata drive that I am sure of.thanks for the tips. and yeah I would for sure do it on a saturday...thanks. sorry earweed I put it in the wrong spot.

hypnotoad

back up the data
test your backup to make sure you can restore it (!)
take old drives out
put new drives in
configure RAID & create disk sets
mount
partition
format
restore
verify

itdaddy

hypnotoad

thanks nicely put..

Plantwiz

hypnotoad wrote: »

back up the data
test your backup to make sure you can restore it (!)
take old drives out
put new drives in
configure RAID & create disk sets
mount
partition
format
restore
verify

This is likely your *most reliable* solution.

I was tempted to mention Drobo...but see it has already been noted. While I like the Drobo products, the price point just isn't quite right for me yet.

As far as using SATA over SCSI...SCSI is still more reliable (IMO and various white paper sources) However, the cost savings using SATA over SCSI (in conjunction with a good backup solution) makes SATA the new winner for 'most' applications.


I think you 'might' be able to accomplish what you want with your method (and few third party apps, several asprin and maybe a small celebration afterward)...and worth a test in a lab scenerio, but I'd say in production, use the above.

RobertKaucher

hypnotoad wrote: »

back up the data
test your backup to make sure you can restore it (!)
take old drives out
put new drives in
configure RAID & create disk sets
mount
partition
format
restore
verify

A little off topic here, but I have to mention the old saying:
"Backups are worthless. Only restores matter."