Comments on: Bad blocks? badblocks!

By: Miguel Arroz

Miguel Arroz — Tue, 06 May 2008 20:09:19 +0000

Hi!

I never actually used this to mount ext2 volumes, so I have no idea if it works fine. Anyway, badblocks seems to work in every machine I tried it, Tiger or Leopard, PowerPC or Intel.

About your problem, apparently you are doing a write-test (which is destructive, be careful!) on a disk that is being used (probably it has mounted partitions). Everytime I saw that message was because the disk was being used, so it could not be tested. That doesn’t indicate an incompatiblity between the OS and badblocks.

Yours

Miguel Arroz

By: Peter Pan

Peter Pan — Tue, 06 May 2008 19:02:48 +0000

Hi,
as I had to find out, Brian’s port does officially NOT support 10.4 or 10.5 - which makes it rather confusing/senseless in today’s Mac OS X to use these tools.
However it might be that badblocks does work fine - but there is no guarantee.

So, I actually installed it and ran into another problem under 10.5. - which now might be a consequence of the lack of support for 10.5 :

MacBook-20:sbin peterpan$ sudo ./badblocks -w /dev/disk1
./badblocks: Resource busy while trying to open /dev/disk1

Any suggestions?
br
Peter from Vienna, AT

By: John Sawyer

John Sawyer — Thu, 17 Apr 2008 22:27:59 +0000

A correction to my correction above: pre-X versions of Norton Utils (don’t know about the OS X version) DO have an option to do a read/write/verify test on hard drives, and have options to either fix files with bad blocks, or to leave them alone. What this fix entails, I don’t know, but I think it may write bad blocks out of the drive’s directory, then create pointers to new blocks, which it fills with zeros.

It’s been a while since I’ve changed Norton Utils’ prefs to do a read/write/verify–I prefer its read-only test, since I don’t know whether to trust its bad block repair option–so I’d forgotten it was there, until I happened to check for it today.

By: John Sawyer

John Sawyer — Fri, 15 Feb 2008 19:40:30 +0000

Thanks, Miguel. I haven’t installed badblocks yet, and wanted to know if it had write capabilities before doing so.

By: Miguel Arroz

Miguel Arroz — Fri, 15 Feb 2008 11:47:50 +0000

John:

With the options -w or -n. Quoting the badblocks man page:

-n Use non-destructive read-write mode. By default only a non-
destructive read-only test is done. This option must not be
combined with the -w option, as they are mutually exclusive.

-w Use write-mode test. With this option, badblocks scans for bad
blocks by writing some patterns (0xaa, 0×55, 0xff, 0×00) on
every block of the device, reading every block and comparing the
contents. This option may not be combined with the -n option,
as they are mutually exclusive.

Note that -w destroys all your information, -n tries not to (unless there’s a power cut or something).

By: John Sawyer

John Sawyer — Fri, 15 Feb 2008 10:20:54 +0000

Greenie says: “The drives never pass OS 9 Norton Disk Doctor’s Read/Write/Verify sector scan.”

Norton Disk Doctor for OS 9 doesn’t do writes during its surface scan, unfortunately. I don’t think Norton Disk Doctor for OS X does either.

One of the best OS 9 utilities that I can remember, for which you could set its prefs to do a continuous read/write test of a drive (which was nondestructive as well, writing the data back to the blocks–nice!) was FWB Hard Disk Toolkit’s “Device Test” option. There were maybe a couple other utils that could do this, but that’s the only one I can remember at the moment. I can’t find an OS X utility that can do this, though there may be one.

By: John Sawyer

John Sawyer — Fri, 15 Feb 2008 09:10:26 +0000

How do you tell badblocks to do a write test?

By: Greenie

Greenie — Tue, 04 Sep 2007 14:22:27 +0000

Be careful running read-only utilities. As Miguel mentions in the comment above, merely being able to read every block from the drive does not necessarily mean the hard disk is OK.

Beware TechToolPro (version 4.5.3 and previous versions at least, I’m hoping they will fix future versions soon), as it simply does a Read test of the hard disk blocks. Many faulty drives pass TTP’s tests, even though I know them to be faulty. The drives never pass OS 9 Norton Disk Doctor’s Read/Write/Verify sector scan. It’s a shame that no OS X utility currently has the same functionality.

I’m dying to find an application that performs speed-related hard disk block-testing. Some Windows products have this functionality.

By: Miguel Arroz

Miguel Arroz — Fri, 03 Aug 2007 16:03:42 +0000

I want to reinforce the “time is an important factor when testing hard drives” statement I did on this post. Some days ago I helped a colleague that was having severe speed problems with his Powerbook. By looking arround, it was easy to conclude that the hard drive was the culprit. The log was full of I/O errors. I run badblocks on it, and it was terribly slow. So, I canceled the scan, and restarted only for the first 50000 blocks. Testing 50000 blocks should take no more than 5 or 10 seconds, depending on the hard drive speed. On the problematic drive, it took more than 5 minutes… but no bad block was detected! So, keep this is mind: speed is important when testing hard drives. Hard drives may suffer from a lot of mechanical or electronic problems, not just errors in the disk surface.

By: João Antunes

João Antunes — Tue, 17 Jul 2007 15:42:10 +0000

The good old memories of Drive Setup in Mac OS 9, where we used it to ‘Initialiaze’ disks…