[lucylawless]

My question is this. In OS 9's disk utility there is the option to do a low level format of a hard drive. Is this function available from the OS X install CD, or any OS X app?

The reason I ask is that I have a sick powerbook whose major symptom is that after being left off for more than about 4 hours it has only about a 50% chance of making it all the way through the boot-up process (in 9 or X) from the hard drive. When this happens, I have to boot from a cd, low-level format the hard drive and reinstall everything. I don't know what a low level format does exactly, and by the way, anyone with an insight as to how I could fix or diagnose this problem please speak up

thanks

[JayTi]

<(---Apple Tech, A+ Tech.)

Whatever you do, DON'T DO A LOW-LEVEL FORMAT! These are done at the factory, and are NOT to be done by a user. This process is the first thing that happens to a drive, and tells the drive exactly 'what' it is, it's capacity, cylinders, heads, you name it.

Trust me, you'll regret it if you do.

[mikemako]

really? I have used zero all data a couple of times and never ran into any problems. that is the same thing, isn't it?
I thought initializing the disk just made all the info on it unrecognizable to any future OS installations, and a low level format is used when one is having serious problems and they need to eliminate bad sectors. i probably don't know what I'm talking about. nevermind.

[gorgonzola]

Are you sure? I'm no Apple Tech, but low-levelling a drive really cleans it out nicely...it's certainly an extreme measure, but definitely a useful one when a computer is just having a lot of issues.

There aren't any negative effects as far as I can tell ... unless you know something I don't?

[edit: s/benefits/effects]

[ 04-04-2002: Message edited by: gorgonzola ]

[Groovy]

JayTi - A low level format is EXACTLY what you want to do when you have bad sectors. It hurts NOTHING. Just make sure you have all your data backed up.

Anyway i did a low level format on an IBM 75 deskstar 2 months ago that over the the 6 months before started having trouble more and more reading and writing to the last platen. After the format all the bad sectors on that platen were mapped out. No problems since.

before i was getting I/O errors like crazy ( failed read/writes ) when more bad sectors show up i will low level format again. none have showed up since.

Doing that saved me from having to buy a new drive. i now use it as a scratch disk.

[JayTi]

If you don't know what your doing, low leveling a drive can seriously screw it up. If something goes wrong in the process of the low level (and it can, and does ~30% of the time) your done. Your hard drive becomes a nice lookin' paperweight. Yes, it can write over bad sectors, it makes the drive go back to when it came out of the factory. I would only do it if you have exhausted EVERY other option. BTW, Re-zeroing isn't the same as a low-level, rezeroing data simply means writing every 1 on the disk, to a 0. Only reason I didn't want you to do it right away, is because I've seen too many bad things happen with you do, and some guy tried to kill me when I told him that he had lost all his data because he started to perform a low level format, and then he tried to blame it on me Anywho, use Norton, use Drive 10, and if ALL else fails, you don't really have much to loose. Good luck.

[CharlesS]

This is baloney. For over 10 years, I've done a low-level format on every hard disk I've formatted, except with the ones that Drive Setup won't let you low-level format - then I do a zero all data. I've never had a single problem.

Doing a low-level format has been a common Mac troubleshooting technique for a long time. If hosed your disk 30% of the time, don't you think someone would have noticed by now?

[lucylawless]

well the fact is I've already done it on this particular drive at least 6 times with no bad results. This computer is no longer my main machine, and with the other mysterious hard drive-related problems, there's no way it's going to have any important data that's not been backed up. I'm absolutely sure that once it refuses to boot fully from the hard drive, a low level format and nothing else (that an Apple boot disk can do) will revive it. Does anyone know if it can be done from OS X?

[HAL9000]

Originally posted by JayTi:
<STRONG>If you don't know what your doing, low leveling a drive can seriously screw it up. If something goes wrong in the process of the low level (and it can, and does ~30% of the time) your done.</STRONG>

Where did you get all that information from? 30%? I do not believe a word of it. Show me some literature/posts where people have had bad experiences.

I have only done a couple of low level formats, but about ten zeroings. No problems AT ALL with either. On the contrary, ended up with a nice clean HD after the zeroing. Takes a long time though. The only time you get into trouble is if you *interrupt* the procedure, and that is well documented.

If Apple wouldn't want you to do it, why do they provide the facilty for it? Stuff of nonsense.

As I said, pl. prove your point.

[cowerd]

As I said, pl. prove your point.

He's almost right

In a recent Mac 911 column I covered the subject of formatting an ATA (IDE) drive. In that column, I mentioned that Drive Setup's low-level format option is dimmed when you work with such a drive. Here's why:

IDE drives work around bad blocks on their own. They do so when the drive tries to write to the block and finds it wanting. Apple suggests that a good way to reallocate the bad blocks on your IDE drive in one fell swoop is to initialize the drive using the Zero All Data option.

You'll find this option by selecting Initialization Options from Drive Setup's Functions menu.)When Drive Setup attempts to write zeros to a bad block, the IDE drive will map out that block.

http://216.239.51.100/search?q=cache:FCai7IxC7xkC:www.oac c.org/scrumpy/Feb2002-09.html+mac+low+level+format+IDE&hl=en
cached google

or this

Low-level formatting is not possible with IDE hard drives, but rather with SCSI hard drives. You can, however, "zero all data" (an option in Apple's Disk Setup utility), which essentially will do to an IDE HD the same thing that a low-level format will do to a SCSI HD. Virtually all of Apple's recent computers use IDE hard drives now.

http://www.appletechs.com/archives/00000055.html

happy now?

[ 04-05-2002: Message edited by: cowerd ]

[wheeles]

Originally posted by mikemako:
<STRONG>really? I have used zero all data a couple of times and never ran into any problems. that is the same thing, isn't it?
I thought initializing the disk just made all the info on it unrecognizable to any future OS installations, and a low level format is used when one is having serious problems and they need to eliminate bad sectors. i probably don't know what I'm talking about. nevermind.</STRONG>

Have you tried booting into single-user mode (hold down Apple and the 'S' key on boot up) and following the instructions to run the filesystem check:
/sbin/fsck -y
This should correct most problems. If I have a few errors I tend to run this a couple or more times just to make sure that no additional problems are found and things look clean.

At this point the disk is in read-only mode. You can either type reboot to do just that or shutdown -h now to shut down the machine. If you want to make any further changes at the command line you first need to make the disk writable. To do this type:
/sbin/mount -uw /

Note that in single-user mode you are in as root, the superuser. So you can do a lot of damage as you aren't prevented from deleting/moving anything.

If you still are getting serious disk problems it is probably best to invest in either some disk checking/maintenance software like Drive 10 (I have this and it works OK) or Norton (I haven't used this but will probably obtain a copy). These should map the bad blocks/sectors out of the way and repair filesystem and volume structure inconsistencies as well as doing comprehensive surface scans.

However, it might be worth considering a new disk. When bad sectors start to appear with any kind of regularity it's usually a sign that the disk is going bad. This will only end up with you losing data. I have a couple of disks in my G4 and regularly create a backup mirror of my system partition in case things go really bad. For this I use Carbon Copy Cloner (see the excellent http://mactips.bombich.com). The rest of my stuff I back up frequently.

Hope this helps you (or anyone else for that matter).

[ 04-05-2002: Message edited by: wheeles ]

[JayTi]

My proof comes from experience. If you guys are low-leveling your drives, fine....but something you may not know, it voids any kind of warranty, and that is well documented on Apple's site, as well as the manfacture's. I'm not going to argue with you guys, if it works, it works, but don't come whining here when you try to low level format it, and something goes wrong, and you try to get another drive under warranty, or whatever. After 5 years of being an Apple tech, and PC tech, I've learned a few things, and I would never personally low-level format any of my drives, in any of my computers, no matter what kind of problems I was having, but meh, thats me.

[JayTi]

[double]

[ 04-05-2002: Message edited by: JayTi ]

[CharlesS]

Originally posted by JayTi:
<STRONG>My proof comes from experience. If you guys are low-leveling your drives, fine....but something you may not know, it voids any kind of warranty, and that is well documented on Apple's site, as well as the manfacture's. I'm not going to argue with you guys, if it works, it works, but don't come whining here when you try to low level format it, and something goes wrong, and you try to get another drive under warranty, or whatever. After 5 years of being an Apple tech, and PC tech, I've learned a few things, and I would never personally low-level format any of my drives, in any of my computers, no matter what kind of problems I was having, but meh, thats me. </STRONG>

How about providing a quote of the part of the Apple warranty where it says that a low-level format would void the warranty?

[JayTi]

It voids the warranty on your hard drive. I'll research it later when I have time.

[HAL9000]

Originally posted by JayTi:
<STRONG>It voids the warranty on your hard drive. I'll research it later when I have time.</STRONG>

Thanks. It's sure appreciated.

[HAL9000]

Originally posted by cowerd:
<STRONG>In a recent Mac 911 column I covered the subject of formatting an ATA (IDE) drive. In that column, I mentioned that Drive Setup's low-level format option is dimmed when you work with such a drive.</STRONG>

Well, if the option is dimmed than one obviously can't do it. Apple's way of telling us not to, but if it's not dimmed with another type of drive. . . ?

Thanks for the links BTW.

[ 04-06-2002: Message edited by: HAL9000 ]

[HAL9000]

from this link http://www.appletechs.com/archives/00000055.html put up by cowerd:

"The above advise suggests that zeroing the drive is a good thing, but I believe it just adds extra wear and tear. However, it *may* keep the average hoodlum from accessing the former contents of your drive."

I don't get the bit about the "extra wear and tear". Could anyone throw light on this?

[ 04-06-2002: Message edited by: HAL9000 ]

[Mac-arthur]

Originally posted by JayTi:
<STRONG>It voids the warranty on your hard drive. I'll research it later when I have time.</STRONG>

Okay, I usually just lurk in this forum--but this is just wrong.

It does not void your warranty. It causes no harm for most drives but if your drive is on the verge of a hardware failure either a low-level format or zero data can cause it to finally fail just because it puts the drive to use of an extended period of time.

Trust me if zeroing your drive would void Apple's warranty I'd know about it!

Arthur

[lucylawless]

Originally posted by Mac-arthur:
<STRONG>...just because it puts the drive to use of an extended period of time...</STRONG>

actually, the low-level format only takes about 3x as long as the standard format (about 30 seconds, not hours on end like zeroing all data)

[Gregory]

All you need to do with IDE drives is run Drive Setup Test. You can run it in the background, and will map out/reallocate bad blocks. it is not done on the fly. Drive Setup does not enable the SMART feature built-into drives. FWB HDT and maybe HDST will report on logged errors by the drives self-test monitoring.

I wish there was a way in Disk Utility but seems totally absent.

As to the original post, you may want to run Disk Warrior. Bad boot blocks are rather common and lead to such problems with booting, unable to find or "remember" the boot loader (bootx for OS X, tbxi for OS 9).

Troubleshooting - When to Reformat Also, Drive Setup: Checking For Bad Blocks goes into ATA zero all and reallocating bad blocks.

EARLIER version of Drive Setup did not dim the "low level" option which could result in problems and was not designed to be run on ATA drives, only SCSI.

Excerpt: ATA (IDE) drives internalize tracking and sparing of bad blocks. Drive Setup and ATA drivers thus have little control over this process. Which is why the low-level format option is dimmed when initializing an ATA (IDE) hard drive. Reallocation (sparing) of bad blocks that the ATA drive tracks will occur when the block is subsequently written to. Thus the best way to force the drive to reallocate bad blocks is to initialize using the write zeros feature. Use Test Disk to verify surface integrity only. Given this strategy, there on occasion may be a need to initialize using write zeros, verify using Test Disk and if any errors occur, attempt to reinitialize using write zeros again.

[ 04-06-2002: Message edited by: Gregory ]

[neps]

Originally posted by JayTi:
<STRONG>It voids the warranty on your hard drive. I'll research it later when I have time.</STRONG>

I just got my powerbook from having its processor replaced. When the repaired machine started showing some weird startup and installation errors, THEY TOLD ME to do a low level format.

since then, the problem s have gone away. I can't see it voiding the warrenty if Apple's Techs are telling you to do so.

This isn't even the first time they have told me to do it. Where I work, I have called in the past for hard drive issues, and they always recommend that before sending the machine in.

Neil