Some free tools with top Google hits:
SmartReporter: see if your drive is reporting an imminent failure.
Cabon Copy Cloner: make a complete, bootable backup of your drive if your external drive is large enough. Then maybe you can do a clean install of your OS.
Earlier today, I created a disk image of my hard drive, saved on the external. Tonight while I’m sleeping, I’ll also copy over my home directory and a few other places I have things saved over the network to my office computer.
Should I take any further action now, or just wait to see if it fails and restore from the backup then?
Did you try SmartReporter, or otherwise get the drive’s self-reported SMART status? It may already be telling you that your drive is about to fail.
Or you could go into the terminal and try:
diskutil info disk0 | grep SMART
Disk Utility used to have this built in, but not since Leopard.
The terminal command will avoid having to install SmartReporter.
It’s shown at the bottom of the Disk Utility window in Snow Leopard and Lion when a disk is selected.
Disk utility says “S.M.A.R.T. status: Verified”. Which I assume means “verified to be good, so far as the tool can determine”.
S.M.A.R.T. status doesn’t necessarily let you know if you’ve got bad blocks. We use Techtool Pro to do a full surface scan on machines that are acting up. It can take a long time, but it tests the entire disk. Apple’s tools seem to sacrifice thoroughness for speed.
So it is. I remember it having been there in the past, and then not being there when I needed it, and now I see is there in Lion again. I knew it: I’m nuts. :smack:
Balthisar, SMART status is only there if you have your disk selected (e.g., “250 GB Hitachi”), not a volume (e.g., “Macintosh HD”). That might explain it… Also, sadly, on both Windows-based and Mac computers, SMART status tends not to be as reliable as some of the other (for pay) utilities. Disk Warrior is a personal favorite, but I’ve heard good things about Techtool, too.
Chronos, you probably know this, but just to note – if you’re going to reinstall the OS, then a disk image is no good, because that will include the bad system/OS files. A backup of your own data (and apps) is much better. It sounds like you’re doing okay, though.
As for whether to do anything else … you could check system.log (Go > Go to Folder > /var/log) for IO errors. Their presence would certainly indicate an issue, although their absence does not indicate a lack of an issue. Beyond that, if the issue keeps happening, you’ll likely want to do something. Restoring from backup (unless you mean onto a different hard disk) won’t help, because nothing will have changed. If you’re willing to invest the time, my vote is still to do an Erase and Install, after having backed up your data and apps.
My thought with the disk image is that, if the drive does fail and I need to replace it, I could restore it exactly from that image.
Yup, you’re absolutely right – just wanted to make sure we were ion the same page. If the issue is your drive, and it fails, then you can restore from that image and pick up where you left off.
(I apologize if I’ve been overly simplistic. I’m used to offering advice to people who don’t understand much about computers.)
Have you booted from the image? How does the OS run when booting from the external drive?
…That’s a good point. I haven’t actually tried booting from the external drive, but if the internal drive failed, I suppose I would have to, wouldn’t I? What’s the standard way of dealing with this?
Well, depending on how you made the backup image, it may not be bootable. Carbon Copy Cloner would have made it bootable by default. If you can see it as an option in the “Startup Disk” control panel, then it’s bootable. Select it in the control panel, reboot, and you’ll be on your way.
Boot from your OS X install DVD it has Disk Util, you can use that to restore from a backup disk image.
You can boot from a USB disk that has an install of OS X on it. Not sure if there’s a way to boot from a copy that’s contained within a disk image.
Hold down Option while starting and you’ll get a list of available startup volumes (including CD/DVD).
What I did was, I used Disk Util to create an image saved on the external drive. That apparently doesn’t make it bootable directly, but it sounds like tellyworth is saying that I could still restore from it using the install DVDs?
Eh, I should probably just install Carbon Copy Cloner and use that; it seems like it’d be more the right tool for the job.
Yes, I’ve never done so myself but certainly the option is there. Details: http://support.apple.com/kb/ht1553
You can also restore from Time Machine using the install DVD, which I have done successfully.