Saturday, December 19, 2009

So I bought a new Intel Mac Mini...

In early 2006 I bought a Power PC (PPC, G4, DDR2-SODIM) Mac Mini to use for a Uni course.
Could've gone Intel, but it was new technology, so I avoided it...

Coming up to 4 years on, and I've filled the disk, the CPU fan is a little noisy, new things like 'Google Chrome' are 'intel-only' and OS/X 10.6 ('Snow Leopard') is Intel only... Plus VMware and Parallels can run on Intel platforms.

This time I paid the ~20% extra for a top of the line 2.53Ghz core duo, 4Gb DDR3 RAM, 320Gb 2.5" SATA - which is roughly 4 times the capacity in all dimensions as the PPC version.

First surprise, doesn't come with a DVI-VGA adaptor in the box. BUT, now there are 2 video connectors, 'mini-DVI' and 'miniPort'. The shop only had a 'miniPort' VGA adaptor on the day and I went home with that...

Attach to KVM, boot and - no monitor found. VGA adaptor works fine directly connected.

Second surprise, 800Mhz Firewire is a 9-pin connector not 6-pin (400Mhz on PPC Mac).

Booted new Mac and it says "got an old Mac?" and gives instructions to reboot the old one "holding down the 'T' key" to start a transfer. Which meant closing out all my running Apps and discovering just what they meant.

Which was hold down the 'T' key whilst the machine was shutting down, before the reboot.
It comes up in 'Transfer mode' - displaying a "firewire transfer" symbol. Apparently you can use an 'ethernet' transfer mode... Didn't try that.

After 2-2.5 hours, the transfer completed - 75Gb moved over. Accounts, Preferences, Applications and User Data copied and working.

I've had to reload Adobe Acrobat Reader, apparently it wasn't a 'Universal Binary'.

Even the licensed & registered 3rd-party software I had (MS-Office, NovaMind, OmniGraffle) 'Just worked' on reboot. The transfer was clever enough to not move system binaries. As a bonus, I got a work Perl system back... In the past I'd installed a second, non-Apple, version and managed to zap on both versions...

Third surprise was initialising "Time Machine". It took 2.5hrs to transfer 75Gb, which is about right - I've timed the old HDD @ ~20Mb/sec sustained raw read rate.

It took a day and a half (!!) for "Time Machine" to initialise... 33-36 hours, Ouch!
The USB drive, a 1Tb Western Digital 'Book for Mac', runs at about 10Mb/sec for raw reads (36Gb/hour).

I can only guess why it ran so slowly... The "Time Machine" is a HFS filesystem.
"Activity Monitor" showed some very large numbers for Gb read from the system Disk, but the amount written to the USB drive matched the progress numbers reported by 'backupd'.

In the middle of the initialise, I rebooted the machine because I could see no evidence of progress.
Rebooted, restarted the initialise and off it went again. Seemed to pick up from where it left off.

There were one or two other times that it took hours, literally, to backup a few Gb.
Now it does 2-3Gb in 5-10 minutes, as you might expect.

What I love about "Time Machine" is this is the first time I've had a good backup system for my home desktop. Seems odd as this is what I do professionally, but there it is.

Another cute thing with "Time Machine" is it can use a Network connected device - like a wireless connected Apple 'Time Capsule' or instructions are out on the web for using a "NAS" - like an old Linux box.

The "Time Machine" interface is well thought out.
You 'enter Time Machine' and the Finder comes 'front and centre', the background changes to 'beginning of the Universe' picture, all the other Apps slide away and the rest of the decorations appear.

When you're done, your desktop just slides back into place. Very cute.

There's a major caveat with "Time Machine" - it's granularity is "whole file".
I use 'mailbox' format (a 'folder' contains all messages in a single file) versus 'maildir' format used by Apple Mail (every message is one or more files in a directory). Everytime a new message gets added to one of my 'folders', the entire file is written. I've looked and there are several which as 1+Gb :-(

It's pretty much 'rsync' with a nice GUI and a few tricks in the HFS filesystem.  One of which I read (to confirm) is that it allows directories to be linked.  This was removed from POSIX because you can get complex loops in filesytems...

Things I don't like about "Time Machine", but aren't reasons to bail:
  •  I haven't been able to find how to turn on decent logging.
    The default syslog entries written in /var/log/system are high-level (#files, total size).
    Where/How do I get a list of the files it dumped?
  • I could exclude Thunderbird's mail folders and save on backup time and space.
    What I'd really like if I could tell it that these files grow by concatenation, and to link to just the most recent version... Though data might be lost if file is truncated, but the semantics of that should be simple. Eg. if the current backup version is perfect subset of the new file, just concatenate the new lines. Otherwise, create a copy.
  • Haven't found, after a quick look, the API. Be nice to be able to integrate with 'rsync'.

'locate' works, but there is some internal magic that seems to exclude 'Desktop' files...
Almost everything is scripts, but I can't find the list of excludes. Perhaps it is just silently failing because of the number of files I have in a directory there...

The Western Digital "MyBook" only transfers 10Mb/sec (36Gb/hr). Seems slow.
If "Time Machine" reads or writes every block on the filesystem, that would explain the initial load time and observed volumes of data read.

Mini-display port versus Mini-DVI.
If two VGA adaptors are used, Display-port is the 'primary' (system boot and menus).
If VGA and DVI on Mini-DVI: the Mini-DVI is the 'primary'.
[Don't have enough dongles to test all combos]

Working with a USB/DVI KVM.
The Intel Mac Mini has a DVI-D connector, the PPC Mac Mini has a DVI-I (integrated, allows for DVI-D or DVI-A).
The connectors on the KVM I bought are DVI-I, which won't plug into a DVI-D socket. (A DVI-D cable will plug into either a DVI-I or DVI-D socket).
I won't spring $50 for a separate DVI-D cable  until I talk to the vendor.

Meanwhile, I saw a $25 VGA to DVI-A cable.
Connects to the KVM, but nothing displays. Presumably because the DVI-D connection on the monitor only does digitial. Who'd have thought :-)

The PPC Mac Mini came with a VGA/DVI-I adaptor. It doesn't work in reverse. :-)

The KVM exhibits the usual "doesn't play well with sleeping computers" problems:
  • While the KVM does connect speakers/microphone through, there is sporadic hum.
  • with 2 or 4 ports connected, put a system to sleep via menu and it is 'woken' after a second or two.  Something to do with the USB  interface of the KVM. Execute a delayed command, flip to another input - All Fine.
  • Single device connected - system will sleep from menu, but at some random time, it's alive again.
  • Waking a system is impossible without unplugging/replugging its USB connection to the KVM
  • Not 'sleep' exactly, The keyboard and mouse sometimes become unresponsive. Either reconnect them to the KVM or reset the KVM (remove all powered connections, including video).
This DVI/USB KVM has the habit of complaining about selecting an inactive port. It will lock up (needs 'reset') if moved to an inactive port. Not sure if that's sometimes or if there on the port for more than a few seconds.

I tried turning off the 'beep' from the keyboard - locked up & needed a full 'reset'. Could've been I swapped it to an inactive port.

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