Hard Disk Failure in G5 Power Mac, need to replace it, i have some question

If you have a PowerMac G5 (PowerPC) there are two SATA drive bays A and B.

There are online pdf manuals for Do It Yourself to installing drives, where the screws are, etc. And the forum for G5s where there are a number of threads on adding, replacing and installing drives is here:
http://discussions.apple.com/category.jspa?categoryID=108

Links to How To and manuals are here:
http://www.apple.com/support/powermac/

Your PowerMac would have come with a small booklet also with photos instructions on adding drives, memory, etc.

As for what drive to get, size? price or any other concern?

When a raw drive is inserted it needs to be initialized and there should be a pop up screen asking if you want to, the only thing that will do is launch Disk Utility where you will have to choose the drive and partition it as needed. It will not install Leopard.

If you are going to install Leopard you need to boot from a Leopard DVD and go to "Utility" menu just before beginning install, or you can also choose Install Options to do Erase and Install I think.

If you have a more recent Intel Mac Pro there are no cables to connect and four drive sleds that you just pull, screw drive to sled, and slide back in. It also uses PCI Express graphics (so does the dual-core and quad-core G5).

Do you have AGP graphics? check system profiler or "About This Mac... more" button from Apple menu for detailed profile info. CPU, number of processor cores, etc, RAM type.

You would need to hold option key or 'c' to boot from Leopard.

A really badly damaged drive can prevent booting from any disk, whether CD/DVD or hard drive, because the system still tries to see if there are other systems out there when it scans the various buses for bootable devices.

You probably need to unplug or pull the old drive to do anything. But you may be able to zero the drive. Partitioning checks the blocks where the partition tables will go, because those blocks can't be remapped later, and some drives fail at that point, but re-partitioning, not just erasing the user partition, is something I do frequently.

Is the 2nd drive bay filled? definitely want to use both drive bays.

Got a FW or other emergency boot drive handy? or small partition on a media drive that has just minimal OS X.

When swapping drives on G5s, NVRAM doesn't always 'learn' or see the new drive properly, so best to zap PRAM/NVRAM or reset nvram to clear the device tree and force it to rescan and recognize new devices (PCI, memory, and hard drives).

I would definitely want a working clone/backup and keep Alsoft Disk Warrior on it to repair and do maintenance of your drives on a regular basis to prevent problems from getting worse.

If you need to recover data, pull the drive and later see if Data Rescue II can see any files. You may need to repair the drive. And Apple First Aid comes up short on disk repairs and doesn't do as many tests and repairs as Disk Warrior.

I always keep a backup spare on hand that I can use if a drive goes out.
http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html

You would need something like USB/FW case that works with SATA drive. Something just for emergency probably, so you can plug in and mount it after the system is up and running.

http://eshop.macsales.com/shop/firewire/

There is an all-purpose kit for about $30.

Even though everything is backed up, have local bootable 2nd drive?

Also, might want to consider having one drive just for OS and apps, 2nd for data and media and home folder, or do you use the server or external RAID storage for editing? If you don't want to have down-time, a RAID mirror, just be sure to buy a 2nd matched drive. Creating a RAID means having to destroy existing files.

What I use are SuperDuper clone for backup of the system so I can restore the system. And avoid having to install, update and configure. SD can use a sparse disk image as well as a regular disk partition. Disk Utility Restore can also be used to create and restore, but won't do smart updates.

If you don't need to recover files, I would just nuke the drive or zero it out - and if it passes a full disk zero, might use it or part of it for running Disk Warrior, TechTool Pro, etc.