Best hard drive practice?

March 4, 2009 5:51 AM

Is CHKDSK actually any good?

I had a problem a few months ago where my hard drive started corrupting my files. I don't blame chkdsk for this, but when I was trying to sort out how I could recover some of these files, somebody implied that all chkdsk did was mark the sector bad, rather than try and save what is on there. Is this true? If so, isn't it a pretty bad hard disk checker?

Now, my hard drive contains many many photos, music and video files, which I want to make sure don't get corrupted or damaged in any way. What would you recommend I use or do to check my files over and make sure they're ok?

TIA.

posted by edbyford to computers & internet (17 comments total)

I recommend that you backup anything you think important. Then backup/rotate the backups.
posted by orthogonality at 5:56 AM on March 4, 2009

I have succeeded in restoring a blue-screening PC to normal function, using CHKDSK alone, on several occasions. That does not mean it is capable of fixing every sort of hard disk data corruption situation.

If your data is important, back it up properly. I use IDrive, and it works great for me.

To answer your specific question regarding "checking" your data files, in my experience some files can become corrupted or unreadable, but in a way that does not trigger detection by CHKDSK or other data consistency checkers. To check them over and be certain they are still good, just open them up and look at them.
posted by BigLankyBastard at 6:05 AM on March 4, 2009

Back them up. Like yesterday. You can't have too many copies of your important stuff.

If you want software to check your disk, Spinrite is arguable the best. Don't mind the website, Steve needs to update it in my opinion.
posted by Silvertree at 6:22 AM on March 4, 2009

Your data may become corrupt in two different ways:

- Data on your disk is organized according to some structure, called a file system. Some information in this file system may be wrong e.g. the size of a file may be incorrectly reported.
- Ultimately, data is pysicaly stored in distinct locations on the magnetic medium. After a (large) number of read/write cycles, a specific spot on your disk may become unusable. This is called a "bad" sector.

CHKDSK (and any other disk checking software) may be able to correct the first kind of error, but no software can fix the second one. In fact, if you have reached the point where CHKDSK is reporting bad sectors, you will probably need a new disk soon as your drive is on its way to magnetic media heaven.

If you lose data in this way, your only recourse will probably be a data recovery company, who will open up your disk, take out the platters and read them using special equipment ( and then charge you an arm and a leg for it). So do as everybody else has already suggested, and backup your important data (on some other medium -- another copy on the same disk doesn't count).

There are ways to verify the integrity of your data (such as calculating a checksum or MD5 hash) but for the home user they are probably more trouble than they are worth, and are not a substitute for a decent backup strategy anyway.
posted by ghost of a past number at 6:26 AM on March 4, 2009

I've used CHKDSK on many many occasions to repair a non-booting / non-functioning Windows computer back to a state where it was usable. I dont know the actual disk-level details of exactly how it does what it does, but its certainly worked enough times for me that its one of the first steps I take if I suspect problems with a hard drive. (And the first thing I do after getting the system back up and running is to backup the clients data)

Additionally, I've seen CHKDSK bring back some pretty messed up hard drives (sometimes took multiple runs of CHKDSK)... and in my experience, if CHKDSK is NOT able to repair a drive, the 3 or 4 other programs I have in my utility kit usually cant either. (Drive is mechanically failing, has the "click of death" or some other catastrophic failure)

As for protecting your files You should definitely have backups. Did I mention make sure you have backups? The small amount of effort you put into configuring a good backup script will save you tons of stress, worry and dismay about your files. (make sure your backup copy is on a separate drive or storage medium.

Backups. Backups. Backups.
posted by jmnugent at 6:30 AM on March 4, 2009

Thanks for the speedy replies.

Re: backups, I back up my important stuff regularly using a combination of Dropbox and JungleDisk, both of which are excellent.

However, if a file becomes corrupt, then JungleDisk backs it up, then it is still corrupt on the backup.

I have far too many files to open them and check them.

And I have SpinRite, and it's great, but as it means I can't use my computer while it's running, and it takes ages, it seems a bit like overkill.

So my real question is, is chkdsk any good? Or is its only purpose to find and mark bad sectors?

What program could I use which I could schedule to run every so often, and I could still use my computer while it's running?

Thanks
posted by edbyford at 6:32 AM on March 4, 2009

Silvertree,
Do you know of any third-party independent testing/report thats ever been done on Spinrite to evaluate it and describe in detail EXACTLY what it does? In the years I've been doing IT Support, I've always had a low opinion of Steve Gibson. His website seems a little to "slick" and vaque. The times I've tried using Spinrite, its never accomplished anything besides wasting my time. (the visual progress/scanning it displays doesnt really convince me its doing anything practical. I dont know of anyone who uses it, much less recommends it.

Not trying to start a flame war.. I'm curious to find any accurate or reputable information that would either confirm OR deny my suspicions.
posted by jmnugent at 6:40 AM on March 4, 2009

@ghost of a past number - you posted while i was typing! Thanks for that, it's helpful info.

Two questions still stand - if a file is corrupt, then gets backed up, then a backup doesn't really help, right?

Is there anything better than chkdsk, preferably free/open source which I could use?
posted by edbyford at 6:40 AM on March 4, 2009

Well.. if a file spontaneously goes "corrupt".... will your backup software even back it up to begin with ?. Most backup software that I know will do some kind of check on the file before attempting to back it up. (which is why you sometimes get backup errors like: "Cannot read file xyz.JPG - backup failed.") YMMV - I'm not a backup software guru, so I guess it depends on what backup software you use, and what algorithms it "massages" the files with before it backs them up.
posted by jmnugent at 6:48 AM on March 4, 2009

However, if a file becomes corrupt, then JungleDisk backs it up, then it is still corrupt on the backup.

To protect importand data from this, you would normaly have rotating backup media.

At the simplest case, you could use two external drives, and alternate them between backups. If a bad file overwrites your current backup, you may still have a good copy on the other disk from last time .
posted by ghost of a past number at 6:50 AM on March 4, 2009

Chkdsk will move data from bad sectors before it marks the sector bad. Chkdsk i find is the best way to fix a bad hdd that has windows .

Also some third party utilities are actually just front ends for chkdsk anyway.
posted by majortom1981 at 7:34 AM on March 4, 2009

Jmnugent,

No, I don't know of any independent third party company. In the years I have been involved with personal computers as a hobby and then professionally, I have lost track of the number of times I have heard people recommend it. I have only personally used it once 2 years ago and it seemed to do the trick, but for the life of me I can't remember why I needed it now. That is a really good question. Maybe it is one those programs that gathered a head of steam via word of mouth and never got really tested. Although I know I have had recommendations from two different "geek circles" for what that counts for. Either way, you aren't going to hurt my feelings. I am all about making life better, not wasting my time.

I never got the used car salesman feel from Steve. Granted that is from listening to him speak via podcasts and other types of venues like that. I had a hard drive fubar years ago and thought Spinrite might be able to fix it, but I didn't own a license yet so I emailed him. He took time to answer all of my questions and actually recommended a different solution.
posted by Silvertree at 7:58 AM on March 4, 2009

Jmnugent, I too have always been highly creeped out by the Gibson website, but when a drive of irreplaceable photos went dead, spinright recovered everything. I agree the show it gives seems pointless, and it took 2.5 days, but when it was done, the drive was working again, at least long enough to pull all the data off it.
posted by nomisxid at 8:12 AM on March 4, 2009

The last time I recall trying to use Spinrite... it estimated a fix time of something like 700hours. (granted, that could simply have been because the hard drive was THAT bad). I let it run overnight and it was still at the very beginning of the drive when I came in the next morning. It made me nervous that "exercising" the drive so much might shorten (the already short) expected lifespan of the drive, so I aborted the recovery.

As far as Steve Gibson,.. the "Controversy" section of his Wikipedia article kinda sums up how I feel. I've never listened to his shows, mostly because his personality seems more like "ZOMG chicken-little sky is falling" than simple level-headed fact-supported industry-verified research. I'd feel more at ease if he was the kinda guy that calmly said: "Here is what I'm seeing, but its open information and I'd like others to verify it / reproduce it." Maybe I'm wrong about him, but years of "controversy" is a hard opinion to change. So its that type of impression that makes me not want to trust his software.
posted by jmnugent at 8:43 AM on March 4, 2009

I think you dont understand what chkdsk is. Its not a recovery application. It simply checks the filesystem and makes changes as needed. In your case its for bad sectors. Yes, it will copy the data from the bad sector into a new one, but it cannot magically fix corrupted data. By the time it finds the corruption its too late. Its important for an OS to come with a file system checker. Afterall, the filesystem is part of the OS.

Spinrite is a recovery application. You would use something like that after the corrupted files have been discovered. Dont blame the filesystem and its tools for a physical failure of your drive.

What would you recommend I use or do to check my files over and make sure they're ok?

Backups of course. Especially archived backups that wont get overwritten and put somewhere safe.

Or you could invest in a raid 1 card and a second drive. A good raid card will automatically monitor for SMART errors and corruption and switch to the other disk if need be.

You can use a SMART monitoring tool like HDTune to see if there any smart errors. It can also do an error scan while the drive is working. Run this once in a while. If you have any bad sectors or other signs of drive death its time for a new drive. I think anything less than that approach is taking a risk.

If you are having more drive problems then average then make sure to check your drive temperatures. You might need to put some extra fans in your case.
posted by damn dirty ape at 9:17 AM on March 4, 2009 [2 favorites]

Regarding SpinRite, I've been doing some freelance work for small office/home setups, where people are pretty poor at backup. Typically, if the drive is bad, I would recommend just getting a new drive and restoring from backup, but this doesn't happen in a lot of cases in these environments.

I've run SpinRite on drives with bad sectors perhaps five times in the past couple of years. The first two times, it didn't do anything useful (the drive was already too far gone in one case). The other times, it actually did recover from some disk corruption, in the sense of doing some recovery from bad sectors and allowing the machine to boot again. In all these cases, I had the client buy a new hard drive, and I used Knoppix or CloneZilla to image the recovered drive to the new one as the final step.

In the last instance where SpinRite more or less worked, it ran for 3 weeks. The client was willing to let it run, because there were a bunch of old WinFax files that hadn't been backed up, etc. In this case, there were large areas of the drive that SpinRite marked as "unrecoverable", and the machine eventually needed to run a Windows Recovery boot to deal with broken DLLs. But it did boot.

So, yes, SpinRite seemed to do something useful. Is it a first line tool? Probably not: I only used SpinRite because there were no backups to fall back on. Also, I'm not particularly convinced about Steve Gibson's notion of running SpinRite every couple of months to "tune" the drive. That's probably snake oil.

Regarding Gibson as a podcast personality, I think he's OK for explaining or popularizing firmly grounded concepts, but he can go off the deep end once in a while. He also doesn't always follow his own SecurityNow advice, and sometimes promotes software or concepts that aren't the way I would do things. The best advice is to realize that's he's a journalist rather than a working systems administrator, and take what he says with a grain of salt. Note that the SANS guys also have an occassional security news podcast. Though they don't, for example, give a tutorial on encryption, I would trust what they say on face value more than I would Gibson.
posted by chengjih at 3:45 AM on March 5, 2009

Seconding CHKDSK as a checker application, not a recovery application. It has a few important tasks it can perform, but it is not a subsittute for Norton Disk Doctor or whatnot.

Regarding Gibson, he's stuck in hyperbole mode, but his software is pretty reliable. In data recovery terms, Spinrite is just OK, though.

Simple equation here. If you're concerned about your data, back it up. Recovery is for people dumb enough to to do that, and no matter how good your software is, there are no guarantees. Especially with large media files, you can easily end up with a big chunk simply unrecoverable, because the disk has been physically damaged.
posted by dhartung at 11:37 AM on March 5, 2009