When my Mac stands next to my Mac

Having a spare moment and idle hands I decided to try and network my Macs. I have an old PPC Mac Mini and a new Intel iMac. The Mac Mini had been sitting in the cupboard for a while so I connected it to my TV and decided to see if I could use it as a simple disk sharer for my network with one or more external disks connected to it.

1. I connected the Mac Mini to my network via wireless, so 11Mbps. My iMac is connected via 85Mbps powerline IP.

2. I upgraded the Mac Mini to OSX 10.5 Leopard and connected a Western Digital My Book 500Gb external drive via Firewire. The Western Digital drive was straight out of the box and formatted FAT32. I used the Sharing tool in System Preferences to add the Mac Mini hard drive and the My Book to the shared disks list.

3. FIRST PROBLEM – No matter the settings whilst I could connect from the iMac to the Mac Mini and see the internal hard drive I could not see the external My Book. Googling revealed that the problem is that Leopard will only share OSX formatted external disks. So I used Disk Utility to reformat the My Book.

4. Success. I could now see and connect to the My Book.

5. SECOND PROBLEM. I could see and connect to the Mac Mini drive and the external drive but any time I tried to write to either drive I got an error message “The operation cannot be completed because you do not have sufficient privileges”. I checked the settings, my account had full rights, I even added “Everyone” to the list and gave them full rights. No joy.

I tried repairing access rights, no difference, I could see the drive but I could not write to it.

I pondered and then wondered. The Mac Mini used to be my default Mac so when I bought the iMac I had used the transfer tool to copy over my account. Perhaps there was a clash somewhere between the two accounts – one old and one new?

So I renamed my account on the Mac Mini from “John Doe” to “Johns” and then added my iMac account name to the user list under “share drives” with my iMac password.

I remapped the drive and success, it worked. So watch out for that if you have migrated accounts from one Mac to another and then want to access the drives on the old Mac.

Of course wireless networking has some significant performance issues –

XBench for Firewire 400 WD My Book 500Gb via wireless:

Disk Test 2.01

Sequential 1.23
Uncached Write 0.62 0.38 MB/sec [4K blocks]
Uncached Write 2.54 1.43 MB/sec [256K blocks]
Uncached Read 1.35 0.40 MB/sec [4K blocks]
Uncached Read 1.98 1.00 MB/sec [256K blocks]

Random 5.51
Uncached Write 3.31 0.35 MB/sec [4K blocks]
Uncached Write 4.76 1.53 MB/sec [256K blocks]
Uncached Read 56.76 0.40 MB/sec [4K blocks]
Uncached Read 5.10 0.95 MB/sec [256K blocks]

XBench for 1Tb WD My Book Essential connected via NSLU2 USB port on same 100Mbps switch as iMacDisk

Test 9.37

Sequential 5.96
Uncached Write 2.99 1.84 MB/sec [4K blocks]
Uncached Write 8.63 4.88 MB/sec [256K blocks]
Uncached Read 7.52 2.20 MB/sec [4K blocks]
Uncached Read 11.31 5.68 MB/sec [256K blocks]

Random 21.98
Uncached Write 18.46 1.95 MB/sec [4K blocks]
Uncached Write 16.05 5.14 MB/sec [256K blocks]
Uncached Read 60.80 0.43 MB/sec [4K blocks]
Uncached Read 20.37 3.78 MB/sec [256K blocks]

So next step is to powerline the Mac Mini but not until I have had several large drinks.


I connected the TV Mac directly to my HomeHub and retested using the Ethernet link between the machines:

Disk Test 2.64

Sequential 1.68
Uncached Write 0.94 0.58 MB/sec [4K blocks]
Uncached Write 2.89 1.64 MB/sec [256K blocks]
Uncached Read 1.62 0.48 MB/sec [4K blocks]
Uncached Read 2.80 1.41 MB/sec [256K blocks]

Random 6.19
Uncached Write 5.68 0.60 MB/sec [4K blocks]
Uncached Write 5.20 1.66 MB/sec [256K blocks]
Uncached Read 60.76 0.43 MB/sec [4K blocks]
Uncached Read 3.82 0.71 MB/sec [256K blocks]


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