A month ago, a few weeks after I upgraded from Snow Leopard to Mountain Lion on my ~2010 21.5" iMac, performance started to deteriorate, and the spinning beachball of death (SBOD) began to appear. (I do think the upgrade is a red herring.)
Safari seemed to trigger it most, though it happened at other times. So I disabled extensions and plugins, etc-- no dice. Then I looked at the console and saw that Kernel: disk0s2 I/O errors often happened when the SBOD appeared.
Questions:
1) I am hoping this is a hard drive problem based on the details below, labeled WHY I THINK DRIVE PROBLEM-- what do you all think?
2) When I wiped my disk (details below) I neglected to save the recovery partition. How do I get this back?
3) For some reason, I cannot boot off of my original snow leopard installation disc-- it always hangs after showing the bootup apple on the gray screen.
4) I also cannot use the "D" key on bootup to hardware test the system.
How can I get my recovery partition back? How can I test my system? Do you think the hard drive will have auto-mapped bad blocks, or do you think an imminent crash will occur?
DETAILS:
Disk Utility showed S.M.A.R.T. Verified, and said "No Apparent" problems with the hard drive (partitions) or volume-- though I am beginning to think that it would say a concrete slab had no apparent problems. I got SuperDuper (yes, I waited until I had problems!) and tried making a current full backup to my time machine disk with SuperDuper, but it hung.
I tried resetting the NPROM and SMC, and around this time the iMac stopped booting-- it would hang with the spinning lines under the Apple on the gray screen forever. This happened regardless of pressing Command-R, or trying to go into Safe Mode. At these times, the top left of the iMac, above the slit, would get very hot. No fan would run.
I tried a number of things. Maybe the option key would have always worked, or maybe I had initially used the wrong key combination for NPROM, or hadn't waited long enough before restarting for the SMC. In any case, eventually I was able to boot again.
WHY I THINK DRIVE PROBLEM:
This time, I got a USB drive (Seagate Backup Plus) and used SuperDuper to back up to it. There were several places where I had to delete files to continue. It always stopped at the same file until I deleted it. On a large file, I attempted to use "Curl -C - -O file://<pathname>" to copy, but it never could copy past a certain point in the file.
This makes me think the problem is indeed a disk error, as opposed to a cable, controller, or software-- unless the controller is hiccupping with a certain bit combination of drive address, which I guess is possible.
I WIPED MY DISK: Anyway, I got the drive backed up with some original corrupted files deleted. Then I used Disk Utility to wipe the original disk, and did one pass zeroing it out. Then I restored the drive.
The result is a wonderfully responding iMac again... but I'm waiting for the other shoe to drop.
Safari seemed to trigger it most, though it happened at other times. So I disabled extensions and plugins, etc-- no dice. Then I looked at the console and saw that Kernel: disk0s2 I/O errors often happened when the SBOD appeared.
Questions:
1) I am hoping this is a hard drive problem based on the details below, labeled WHY I THINK DRIVE PROBLEM-- what do you all think?
2) When I wiped my disk (details below) I neglected to save the recovery partition. How do I get this back?
3) For some reason, I cannot boot off of my original snow leopard installation disc-- it always hangs after showing the bootup apple on the gray screen.
4) I also cannot use the "D" key on bootup to hardware test the system.
How can I get my recovery partition back? How can I test my system? Do you think the hard drive will have auto-mapped bad blocks, or do you think an imminent crash will occur?
DETAILS:
Disk Utility showed S.M.A.R.T. Verified, and said "No Apparent" problems with the hard drive (partitions) or volume-- though I am beginning to think that it would say a concrete slab had no apparent problems. I got SuperDuper (yes, I waited until I had problems!
) and tried making a current full backup to my time machine disk with SuperDuper, but it hung.I tried resetting the NPROM and SMC, and around this time the iMac stopped booting-- it would hang with the spinning lines under the Apple on the gray screen forever. This happened regardless of pressing Command-R, or trying to go into Safe Mode. At these times, the top left of the iMac, above the slit, would get very hot. No fan would run.
I tried a number of things. Maybe the option key would have always worked, or maybe I had initially used the wrong key combination for NPROM, or hadn't waited long enough before restarting for the SMC. In any case, eventually I was able to boot again.
WHY I THINK DRIVE PROBLEM:
This time, I got a USB drive (Seagate Backup Plus) and used SuperDuper to back up to it. There were several places where I had to delete files to continue. It always stopped at the same file until I deleted it. On a large file, I attempted to use "Curl -C - -O file://<pathname>" to copy, but it never could copy past a certain point in the file.
This makes me think the problem is indeed a disk error, as opposed to a cable, controller, or software-- unless the controller is hiccupping with a certain bit combination of drive address, which I guess is possible.
I WIPED MY DISK: Anyway, I got the drive backed up with some original corrupted files deleted. Then I used Disk Utility to wipe the original disk, and did one pass zeroing it out. Then I restored the drive.
The result is a wonderfully responding iMac again... but I'm waiting for the other shoe to drop.