[Ti] [Ti]Journaling, was --> Journeling.

[Kynan Shook]

Kernel panics aren't the only way to have data lost.  I'm not sure 
exactly what in the OS would have to fail to cause a half-performed 
write; just plain freezing comes to mind, plus power outages and the 
like.  Bad memory could certainly contribute to these things, since 
many people have no-brand memory (I'm talking about the chips, not the 
whole stick) and have no clue.

Anyway, working in computer repair for several years, I encountered 
many, many, many people who had corrupt directories; inconsistencies 
that probably got started because their computer crashed once, and then 
two years later the errors had built up so much that their computer 
would no longer boot or mount the hard drive.  Of course, this always 
happens to a file that wasn't backed up, and had to be sent to a 
{professor, boss, relative, pick one} yesterday, and would take days if 
not weeks or months to reproduce.  Seems to me that a slight 
performance hit is worth more reliability.

Anyway, you're free to actually perform a benchmark if you like; I'd do 
it myself, but I'm writing this on a plane as I go on vacation for a 
couple days, and I'm also in the middle of moving from one apartment to 
another.  If I remember, I'll try and test it before the end of the 
month (if somebody really cares, remind me then).  I'd recommend 
testing copying a large file on a single hard drive, copying a large 
file from one drive to another, copying many small files on a single 
drive, and copying many small files from one drive to another; try all 
with journalling turned on on the hard drive that is being written to, 
and then again with journalling off.  If you're really ambitious, you 
should try it with a variety of systems; I only have my two PowerBooks 
to test with, so perhaps somebody else will test with a G5 (on Serial 
ATA) and a G4 desktop (with parallel ATA).

However the benchmark turns out though, remember that the supposed 10% 
slowdown is only slowing down something that your computer spends much 
much less than 1% of its time doing, and neither you nor the computer 
generally has to wait around for the write to complete.  You spend 3 
hours writing a Word document, you save it every 5 minutes, and it 
still takes you far longer to hit Command-S than it does for the 
computer to actually write the file.  It might make a difference if 
you're copying a few GB of data from one place to another, but very few 
people do this frequently, nor do they necessarily have to stop work 
while the data copies (eg start a large copy, go work on something else 
while it completes), and additionally, the writing speed of the drive 
often isn't the bottleneck; most drives will write faster than they can 
read, plus often when copying from a network, the network is the 
weakest (errr, slowest) link in the chain.

The one time that I can think of that somebody would regularly copy 
several gigabytes of data, may have to completely halt work while doing 
so, and would have other I/O devices that can keep up with the hard 
drive is digital video, which I already mentioned as being a good 
excuse to turn journalling off.

Also, to offset the slowdown when writing files, reading and writing 
speeds are both improved; reading by moving the most-read files to the 
hot zone on the disk, and both reading and writing are sped up by the 
automatic defragmenting that is happening on the background.  Turn 
journalling off, and you lose these features.

If speed is *truly* essential to you, buy the highest-capacity 5400 RPM 
laptop drive you can find, or even better, as you've already found, get 
an external drive running at 7200 RPMs or better (again, higher 
capacity will also generally give you better speed).  Heck, you can 
even get a battery-powered RAID if you need to.  Either of those 
upgrades will give you a much larger speed boost than Journalling will 
give you a performance hit.

If you do decide to turn journalling off, at least buy DiskWarrior and 
run it once a month or so.  It'll fix all those little problems that 
crop up in directories that you don't know about until a catastrophic 
failure after which you can't read the disk any more.

On Aug 6, 2004, at 5:08 AM, b wrote:

> With all due respect, running a 667 Ti here, that i keep maintained to 
> the max, with external Firewire 800 drives running on the PC card slot 
> (that read/write 10MB/sec faster than the internal IBM drive), and a 
> GB of RAM, and some free disk space.... why on Earth would I want to 
> save, what, 30 seconds once a week on a reboot, and, in return, give 
> up 10% of the speed on a constant basis?
>
> The logic escapes me totally. In 2 years I've had a grand total of one 
> kernel panic. Big deal.
>
> Lost data due to anything software/hardware related? ZERO.
>
> Acidentally hard-rebooting when a big app freezes causes a reboot that 
> takes about 1 minute 17 seconds. Normal reboot time: 1:17. Where's the 
> 'issue'? Reboot when booted into OS 9?  Under 40 seconds.
>
> Analysis: Apple's 'hybrid' OSX (mach/Darwin/pdf/QuickTime window 
> manager/Finder has enough problems (speed included0, so why add to the 
> load?
>
> Giving up 10% (if it's even that little) on a constant basis, in 
> return for a marginally quicker restart after a catastrophic crash 
> (how often are they happening i'd like to know), ... is like losing 10 
> bucks every five minutes and saying, "It's cool, I put 30 bucks in my 
> savings account every two weeks." Sounds inefficient, pointless, and 
> almost totally unnecessary.
>
> My advice: Back up your docs, email addresses, and passwords to a 
> gold-ongold CD or DVD, Keep your installers, and dump anything that 
> slows down the Mac. People, everywhere it seems, are 'filling-up' on 
> utilities that perform tasks that the OS can already do on its own, 
> and why? More clutter, more variables to sort through in cases of 
> conflicts... wasted space, and more missed opportunities to really 
> know and use the OS that's right in front of us (the one 'hidden' by 
> the GUI, of course).
>
> A Finder that uses thousands of _DS files to supposedly keep track of 
> each folder's contents, etc, and then pauses whenever any folder or 
> menu item is clicked for the first time after a login, and can't even 
> remember to "Open all new folders in Column View" (why is that 
> 'option' even included?)... does not need more 'baggage'.