Archive for ‘Data recovery’


Back to Snow Lion: Why Lion needs some work

In hindsight, I’m not sure why, but I upgraded my fantastic 11″ MacBook Air from 10.6 to 10.7 the day that Lion was released.

At first, I liked the changes.  I still think that Mission Control is a nice improvement over Spaces and Expose, but otherwise, there aren’t many compelling new features for me in 10.7.  Still, change is inevitable, so I may as well get used to the backwards scrolling, the noticeable drop in performance, and all of the other new changes, or so I thought until I started using 10.7 day-to-day.

Since August, I have been using 10.7 on a 24″ iMac, my 11″ MacBook Air, a 24″ iMac at work, and a 15″ MacBook Pro at work.  It’s been more or less fine on all machines except the MacBook Air, which is the one I use the most.

On the Air, I’ve had spotty WiFi behaviour where it had been perfect previously, the occasional lock-up, and most alarmingly, it was through it that I learned of Preview and Finder’s new bad behaviour in 10.7.

Try this on a 10.6 machine:

  1. Make a directory
  2. Drop 20 images in
  3. Name them in order:  1.jpg, 2.jpg, 3.pdf, 4.png etc.
  4. Highlight them all
  5. Open them in preview.
You will have a single window open with files 1.jpg, 2.jog, 3.pdf, 4.png… open.  Now you can view them as a slideshow.  Perfect, simple, obvious, hurray.
Now do the same thing in 10.7.  I’ll wait.
See, what a mess?  You will get some of the 20 images opening, out of order.  Others will say “You downloaded this from the internet…”  some will just not open.
Now, try doing this with seven folders of 20 images with a room full of people wanting to see slideshows.  Even better, try it on day four of not enough sleep.  I did.  It wasn’t fun.
So, it’s back to 10.6 on the MacBook Air.  I’ve only been running this way for an hour or so but the system is humming along nicely.  It’s faster, scrolling works like it should, Preview works like it should, wifi is working perfectly.  Perfect, simple, obvious, hurray.

Downgrade from Lion to Snow Leopard using Time Machine Backups

I am truly amazed by just how good Time Machine is.  I wish that an equivalent backup system existed for every other OS.  It’s that good.

With that out of the way, here is how I reverted from 10.7 (Lion) back to 10.6 (Snow Leopard) on my MacBook Air using my original Snow Leopard USB recovery drive and my Time Machine backups, which I had used both before and after upgrading to 10.7 back in August:

  1. Take a clone of the Lion drive using Carbon Copy Cloner just in case I change my mind/had problems.
  2. Once completed, go to System Preferences -> Startup Drive and select the recently cloned drive, reboot from that to verify that it worked.
  3. Shut down.
  4. Plug in the USB recovery media.
  5. Power up, holding down Option/Alt to boot from the USB key
  6. Once booted, go to Disk Utilities and wipe the 10.7 drive.  (May not be necessary)
  7. Under Utilities, choose “Restore from Time Machine Backup”
  8. Plug in my TimeMachine drive and pick the last 10.6.8 Time Machine backup
  9. Wait.  About an hour from a 5400RPM USB drive to the internal SSD
  10. Reboot.  You’re done!

I use dropbox for everything important, so my files were all synced back.  If I happened to miss anything, I have the CarbonCopyCloner copy of my Lion drive on another USB drive.  Easy.

One other thing to note is that I originally wiped and reinstalled 10.6 and then tried to recover from the Time Machine backup. This failed because I had used the Time Machine drive after upgrading to 10.7.  It was then that I rebooted to recovery media and restored using steps 7-10 instead.  So, don’t freak out, and yes you can use Time Machine drive with both 10.6 and 10.7 backups to restore.



Since they asked… My survey submission to Seagate

At work we have a boatload of Seagate ST3500320AS drives. They’re all failing. On a recent RMA submission of 4, and then 6 such drives, Seagate asked me for my feedback. Here it is:

Every one of our approximately 100 Seagate 500GB SATA drives appear to be failing.  Of the approximately 20 drives that I have RMAd, about 5 have already failed a second time.  Due to the sensitive nature of the data on some of these drives, I am forced to destroy them rather than RMA them a first or second time.

This not only causes major work disruptions, but it has left me with no confidence in the AS line of drives, or in Seagate’s RMA returns.  I still buy Seagate NS series drives (one of which I have just RMAd) and Seagate’s XT line of laptop drives, but overall I am now having to move to other brands of replacement drives, just to ensure that I don’t interrupt peoples work twice.

Seagate has not handled these failures well, and I am now moving to WD or Hitachi drives in workstation machines.

On the positive side, I was quite impressed with my recent telephone experience with Seagate.  Your drives may be failing repeatedly at alarmingly high rates but at least your service people are nice and competent.

Ben Hall
School of Computing
Queen’s University

Do yourself a favour, don’t buy Seagate 3.5″ AS-series SATA drives.  As alternatives, I’ve been buying WD Blue or Black series for the same price.  I’m also very impressed with Seagate 2.5″ Momentus XT drives.  These platter/SSD hybrid drives are very fast and quite reasonably priced.  I have 4 now, all are performing well.  Of course, so were these AS-series drives for the first year or two…


Why I’m picky about the laptops I own

Every once in a while a see a great deal on some low-end laptop at BestBuy or Future Shop.  I’m tempted.  The latest was an 11″ Gateway netbook that was $239.  I resisted.  After all, my ThinkPad X40 cost less than that and at $344, the X60s was about the same price as most new low-end netbooks.

This evening I was reminded of why I stick to ThinkPads, HP EliteBooks, MacBook Pros, and other used higher-end machines when I dropped my wonderful (and tough) HP 2710p from a five foot cart onto a very unforgiving tile floor at work.  It was a bad drop, awkwardly landing on a corner.  Couldn’t have been worse unless I’d thrown it down.  I’m usually very careful but this time it just happened and I couldn’t stop it.

The battery popped out, as did the stylus, there is some slight cosmetic damage by the rarely-used SD slot but it is otherwise completely unscathed.

Once again:  I’d rather a high-quality used machine than the newest, shiniest junk on sale in the weekly flier.


Linux ext3 undelete: It is possible

Okay, just a quick one here:

In ext2 (the old default Linux filesystem) there was an undelete.  It was OK and mostly worked.  Then ext3 came along.  ext3 is great.  No more forced fsck on boot, wonderful.  But, filesystem changes made undelete an impossibility.  This was a design decision, it was written on the Internet, it must be true.

Or so I thought.

It turns out that Carlo Woods had the magic combination:L  Lots of time and a never-say-die attitude. The result:  He figured out how to undelete files on an ext3 filesystem!

I’ve tried it, it works.  It was by no means straightforward and certainly isn’t an easy task, but it works.  Yippee!

And before you ask:  Yes, you really do have to read most of his page to get your files back. 😉