# macintosh install of EXT. H.D. question **URL:** \ **Category:** Factual Questions\ **Created:** [October 24, 2004, 1:32pm UTC](https://boards.straightdope.com/t/macintosh-install-of-ext-h-d-question/270890 "2004-10-24T13:32:41Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Weeks](https://avatars.discourse-cdn.com/v4/letter/w/bbce88/32.png) [@Weeks](https://boards.straightdope.com/u/Weeks)\ **Post date:** [October 24, 2004, 1:32pm UTC](https://boards.straightdope.com/t/macintosh-install-of-ext-h-d-question/270890/1 "2004-10-24T13:32:41Z")
I bought a 200 GB external HD because my old 333 is so crammed full of stuff and I figured I could shift a whole bunch of stuff over to it and help out. When I plugged it in and tried to drag things into it, I got a message saying the"new volume" cannot be modified. The cd doesn’t seem to be of much help, and the fact that I’m not to saavy doesn’t help either. Anyone know of an online tutorial? Some advice? A kick in the pants? Thanks john ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [October 24, 2004, 1:50pm UTC](https://boards.straightdope.com/t/macintosh-install-of-ext-h-d-question/270890/2 "2004-10-24T13:50:35Z")
Presuming you’re on 10.x, have you tried the Disk Tool (in the utilities folder of your Applications folder). First try ‘repair disk permissions’ on the new disk, and if that doesn’t work, use the reformat option, since you currently have no data on it. I’m not an expert, by the way, just a Mac user. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [October 24, 2004, 1:59pm UTC](https://boards.straightdope.com/t/macintosh-install-of-ext-h-d-question/270890/3 "2004-10-24T13:59:30Z")
I’m not a mac maven, but if you want those that are to be of help, you need to give more info as below. Most external drives come pre-formatted for windows. If this is a Windows/Mac compatible external you may need to partiton and format it for use with Mac before it will be recognized. What is your mac model and OS version? What is the specific external drive model? Are you using a firewire or USB connection? Is there disk prep software that came with the drive? Have you used it? Is the drive mac represented to be compatible out of the box, or does it need to be formatted/partioned specifically for your computer? Here’s one note from Western Digital > [@](#): > > ``` > Are EIDE drives larger than 137GB (128GB binary) supported in Mac systems? > > ``` > > Question > I am considering buying an EIDE drive larger than 137GB for my Mac system. Are EIDE drives larger than 137GB supported in Mac systems? > > Answer > Not all Mac systems can properly support EIDE drives larger than 137GB (128GB binary). In many cases, the system needs to be a newer Mac G4 or G5 system. According to Apple, there are two primary requirements that must be met to support these drives: > The computer must have Mac OS 10.2 or later > > The system BootROM must provide support for the drive > For full details, please see Apple Document #86178 at Apple. Enter 86178 in the keyword search box on their website. > > Note: There are third-party controller cards designed for use with large EIDE drives and Macs. Please contact Apple or the card manufacturer to find out if a specific controller card will work with your Macintosh. According to Apple, you must still have OS version 10.2 or later, even with the controller card, to use the full drive capacity. ---
**Author:** ![rjung](https://avatars.discourse-cdn.com/v4/letter/r/45deac/32.png) [@rjung](https://boards.straightdope.com/u/rjung)\ **Post date:** [October 25, 2004, 5:54am UTC](https://boards.straightdope.com/t/macintosh-install-of-ext-h-d-question/270890/4 "2004-10-25T05:54:43Z")
Click on the new drive, then choose “Get Info…” from the File menu (or just press Command-I). Open the “Ownership & Permissions” tab and see if you’re allowed to write to the external drive. By the way, though you didn’t mention it, did you just plug in the drive and expect it to work automatically? Or did you format it first, using the “Disk Utility” tool?