defragmenter

Psst… Wanna compete with Best Buy?

Dave Farquhar Software , , , , , , , ,

Best Bait-n-Switch is offering a service where they’ll remove crapware from a PC for 30 bucks.

You can offer to do the same thing for 30 bucks, but do a better job. Here’s how.Of course, the first thing you do is go into Add/Remove Programs and remove everything in sight, unless it’s something the client actually wants. That’ll take about 20 minutes, tops, and it’s probably the extent of what Best Buy does. That’ll help, but it doesn’t bring back all of the new PC peppiness.

Next, you need to install and run a couple of utilities. Start out with CCleaner to remove any stray registry entries that may linger behind. Hopefully there won’t be too much. Then grab the unbeatable Donn Edwards bundle of JK-Defrag, NTREGOPT, and Pagedefrag.

Run NTREGOPT to remove the slack space from the registry, then run Pagedefrag and reboot. You’ll end up with a defragmented pagefile and a fresh-as-a-new-install registry.

Finally, run JK-Defrag to move all the useless data to the end of the drive, and all the stuff people actually use to the front. It’ll do a much better job than Microsoft’s built-in defragmenter, even on a new system.

The tuneup should take less than an hour, and most of it is time you can just walk away from the system and let it do its thing. You can advertise your service as better than Best Buy’s and compete solely on that, or beat them on price by a few bucks while providing a better and more worthwhile service.

If you’re feeling really industrious, you can even consult the appropriate Black Viper services list and disable unnecessary services to free up a little RAM and CPU time. If you don’t want to do a lot of reading, Computer Browser and Remote Registry are two services that always make sense to disable in home environments. My personal list used to be a lot longer, but Windows’ defaults are a lot more optimal than they were 5-8 years ago. The other stuff I always used to disable is disabled by default now.

And here’s one last piece of valuable advice you can give your clients. Rather than buy the Norton or McAfee antivirus product that’s probably installed on their computer as trialware, delete it and have your client buy NOD32 instead. The price is comparable to the other products, but it consumes a lot less CPU time and memory than the rest. So if you want antivirus protection but also want the computer to stay peppy, that’s the best choice in town.

Registry optimization

Dave Farquhar Windows , , , , , , ,

I gave my Windows 2000 system a little tuneup today. Nothing major, but it feels peppier now, and didn’t take all that long to do. Nor did it require any expensive utilities.

This works with Windows 2000, XP, NT4, and Vista. For Windows 9x advice, you’ll have to turn to an old critically acclaimed book written by someone you’ve never heard of.First, I ran Ccleaner, which does a general cleanup of temporary files and obsolete/incorrect registry entries. It found more than 300 MB of garbage to get rid of. Be sure to run both the file and registry cleanup, as they’re separate buttons. It found a lot less in the registry that needed to go.

Stage 2 is to run NTregopt. I recommend downloading the all-inclusive collection from Donn Edwards, which includes NTregopt, plus the Sysinternals system file defragmenter and the excellent JK-Defrag. NTregopt packs the registry, removing the empty space formerly occupied by now-deleted entries. In my case, it reduced the size of the registry by about 200K. Not a lot, but I don’t do a lot of installing/uninstalling on this system.

Stage 3 is to run the Sysinternals Pagedefrag, which is included in the Donn Edwards bundle. In my case, most of my registry files were in nice shape, but one of them was in a startling 28 fragments. Pagedefrag took care of that.

Of course, while you’re at it, it doesn’t hurt to do a general defragmentation. JK-Defrag is fantastic–much better than most commercial programs, and it’s free. In my younger days I might do a quick defrag both before and after registry optimization, but one defrag afterward takes less time and should usually suffice.

The registry optimization took about 10 minutes total, including the reboot. The disk defragmentation took another 45 minutes, but there was no need for me to sit and watch that.

The system boots faster now. It also feels peppier, but since the registry wasn’t in horrible shape, I’m guessing the defragmentation did more to help system speed than the registry work. Getting rid of 300 megs of garbage and moving a few gigabytes of rarely used data files to the end of the disk to make room up front for the stuff you do use makes a difference.

The nice thing is that optimization like this used to require a $99 software package, like Norton Utilities or Nuts & Bolts, and both of those packages also installed some junk that really did a lot more harm than good (like Norton Crashguard, which I used to call Norton Crashmaker). I devoted an entire chapter of the aforementioned book to installing and using utilities suites while keeping the problem-causing stuff off your system.

Today, you can download and install two files that do it for free and stay out of your way except when you need them.

The best defragmenter for Windows NT, 2000, XP and Vista

Dave Farquhar Windows , , , , , ,

Want Diskeeper’s features without ponying up 50 bucks?

Sorry, I can’t help you. The combination of My Defrag, Scandefrag, and Pagedefrag is better and it’s free.

Scandefrag defragments your system during the boot process, as early as it can. It works better on NT-based systems like Windows 2000 and XP than it does on 98 or ME. All it does is launch the other tools.

Pagedefrag is, of course, a classic. It’s just convenient to bundle it up with these other tools. This tool defragments your registry and swap file(s) at boot time, which is the only time the system allows it.

My Defrag (actually Jerrod Kessels’ defrag) is, to put it simply, the best general purpose defragmenter for Windows NT, 2000 and XP that I’ve ever seen. Period.

If My Defrag can’t do an ideal job, it does the best it can do. Some defragmenters leave a file alone if they can’t defragment it, but this one will defragment as much as possible and move it as close to the front of the disk as possible, where performance is much better. On full disks, this is important. Since ideal conditions almost never exist (except when a system is first built), a defragmenter’s performance under less than ideal conditions is very important.

The most exciting thing about My Defrag is its ability to sort files. I like Sort alphabetically.

Sorting alphabetically (the -a7 switch) helps because it uses the full pathname. This means all of your files that are part of, say, Mozilla Firefox will be put as close together on the disk as possible, so when you launch Firefox, all of those files are close together and the disk head doesn’t have to move around a lot. The result is an application that launches faster.

So how often should you defragment? Once a year, I would do a boot-time defragmentation with Scandefrag to whip the Registry and swap files into shape. When that finishes, I would run My Defrag in full optimization mode, with file sorting. If you make a major change to your system (say, upgrading your office suite), do a quick defragmentation after the install and a full defragmentation a month or so after.

As part of your routine system maintenance, a faster, automatic defrag with no options specified is a good idea on occasion. The author says to do it no more than once a day and I agree. In my experience, once a week or even once a month is almost always fine. The way My Defrag works, the system shouldn’t get terribly fragmented on a daily basis, even if you use your system heavily. Defragmenting too frequently can shorten a hard disk’s life expectancy, although the occasional defragmentation seems to help it. I defragment a few times a year (and always have), and I generally get five or six years out of a hard disk, which is a year or two longer than most experts say to expect.

Don’t waste your money on any other tools. Download this trio, install it, use it, and watch your system performance climb.

Ways to keep your NT/2K/XP system defragmented

Dave Farquhar Windows ,

Defragmenting on a regular basis isn’t the only thing to overall system performance, but it’s a major factor. Fortunately there are some free tools that do a good job of it. Unfortunately they don’t come with Windows.

Here’s how to automatically defragment your system and your registry.

You can defragment the registry using PageDefrag, a utility by Mark Russinovich of WinNT Magazine fame. I’ve been known to set it to defragment the registry and page file at boot time; after the first time it doesn’t add much to the boot time at all. And XP can still get itself defragmented and booted faster than NT4 usually could manage to boot.

I talked a few weeks ago about DIRMS, a command-line defragmenter. I still like it. I recommend that you schedule a defrag at sometime you won’t be using the computer, like 4 AM. It’s easy to do with any version of Windows using the AT command.

at 4:00 /every:Monday dirms c -q

The AT command requires the scheduler service to be running. It does not require Internet Explorer 4.0 or newer to be installed, so it’ll run on NT4 boxes that only have the default IE 2.0 installed. If you want to run on additional days, separate it with a comma.

Now if DIRMS would just sort files by access date when it defragments, it would be the ultimate defragmenter.

Update: I don’t like DIRMS anymore. It failed me once big-time, and then I found something better.

Disk defragmentation in Windows 2000, XP, and, uh, NT4

Dave Farquhar Software ,

The disk defragmenter that Microsoft includes with Windows 2000 and XP really stinks up the place.

I’ve been playing with an alternative.It’s free. It’s called DIRMS, an acronym for Do It Right Microsoft.

It’s text mode. That means XP and NT owners can schedule defragments without paying for Diskeeper, which is good, because Diskeeper is barely better than MS’s defrag because they were written by the same company.

DIRMS uses the same built-in API so it ought to be safe but it uses a different algorithm. Whereas Executive’s programs won’t even try to defrag a file if it can’t do it completely, DIRMS just does the best it can. And unlike Diskeeper/Defrag, it moves files to the front of the disk, just like Win98’s Defrag, which increases performance further.

I’m not ready to put it on any system I care about yet, but I think it has a lot of potential. Rather than running Defrag four times to clean up a disk, I can run DIRMS followed by Defrag to mop up the operation and get a disk that’s almost 100% defragmented.

In fact the two programs seem to do better in tandem than either could ever do on their own. At any rate, it’s free, and worth checking out.

Squeezing some life out of an aging Windows 2000 PC

Dave Farquhar Windows , , , , , ,

I can safely say I really did write the book on Windows optimization (Optimizing Windows for Games, Graphics and Multimedia, O’Reilly, 1999, ISBN 1565926773) but that was five years ago and covered Windows 95 and 98.

Windows 2000 and XP are a different animal, and are as similar to the obscure OS/2 operating system from IBM as they are to Windows 95/98.

Here’s what I did when my work computer slowed to the point that I could no longer do much work.Clear some disk space. This is a biggie. NTFS, Windows’ file system, really doesn’t like it if the amount of free space on a disk drops below 15 percent. That’s stupid, but it’s reality, and since I don’t have Mr. Gates’ phone number I can’t do much but live with it. I went to Start, Search, picked Files and Folders, typed *.* in the name field and Drive C in the Look in: field, then hit Search Now. When it finished, I clicked on the field that says Size, and scrolled all the way down. I found lots of big files I didn’t need. I found a mystery file that was 600 megs in size. A Google search revealed that some obscure application I had used once had created that file. That was nice of it. After five minutes’ work, I had freed almost a gigabyte of disk space.

Uninstall old printer drivers. I had a bunch of printer drivers installed for printers I don’t use anymore. They were taking up disk space and memory. I only have 192 megs of RAM and most of it was in use by the time the computer booted, before I’d even loaded any programs. That’s no good. So I removed the drivers for my girlfriend’s Epson color printer (in the Add/Remove Programs control panel) and then I went into Printers and deleted the network printers of old clients and other printers I can’t remember ever using (in most cases you can just delete the printer and it will offer to remove the drivers).

Stop unnecessary services. If you right-click on My Computer and hit Manage, then double-click on Services and Applications and then on Services, you’ll find all sorts of stuff that Windows runs just in case you need it. Most of it is necessary, but for me, several were just chewing up more RAM than I could afford.

Computer Browser. This service, despite what you hear elsewhere, has nothing to do with web browsing, My Network Places, or anything else useful. All it does is permit your computer to participate in browser elections. What are those? It’s a long story, but the gist of it is that on a Windows network, one computer gets to keep the list of computers on the network, and every time you turn a computer on, the computers running the Computer Browser service fight over who gets to keep that list. Sound useless? Unless you’re in an office network with a file server and a very small number of computers, it’s very useless. Most of the time it’s just chewing up between 2 and 8 megabytes of your precious RAM. Forget that.

HID Input Service. I plugged a USB mouse into this computer once and it loaded this. Next thing I knew, my available memory had dropped by 6 megabytes. Six megabytes! For a stupid mouse? I use a USB mouse occasionally, but not every day, and certainly not often enough to be able to afford dedicating 6 megs to something that sits there waiting for me to plug one in. I’d leave it if I had 512 megs of RAM but I didn’t, so I disabled it.

Automatic Updates and Background Intelligent Transfer Service. I keep Automatic Updates turned off because it doesn’t work with our firewall, but whether the option is turned on or off, these services are loaded and chewing up memory. So I disabled these services. I have mixed feelings on Automatic Update. If you can’t remember to visit the Windows Update site once a month, you should leave it turned on. But since it won’t work for me anyway, I have to leave it turned off, so I might as well recover the memory.

Remote Registry Service. This allows a network administrator to connect to your computer and make changes. In a home environment you won’t use this. At work you’ll probably get your hand slapped if you disable it. It uses about a meg.

By trimming some of this dead wood, I was able to gain almost 32 megs of RAM.

Uninstall programs you’re not using anymore. I had several programs that I hadn’t used since Clinton was president that were taking up space on my drive, and some of them had been so nice as to install services that were running all the time and chomping some of my very scarce system RAM. Clearing those out gained me a couple hundred megs’ worth of disk space and nearly 20 megs of RAM.

Clear the browser cache. Internet Explorer keeps pieces of web sites on disk in case you ever visit them again, because it’s much faster than downloading them again. The problem is it does a terrible job of cleaning these up, so the result is you have, in all likelihood, tens of thousands of tiny files, if not hundreds of thousands, that you’ll never use again. Right-click your IE icon on the desktop, hit properties, and click Delete Files. You’ll save yourself some disk space, but more importantly, you’ll make this next step a lot faster and more effective.

Defrag. I used to be really good about defragmenting my drives but it looks like I’ve been lax lately because my C drive was in bad, bad shape. Go to Start, Programs, Accessories, System Tools and pick Disk Defragmenter. Run it once a month.

My drive, as it turned out, was hopelessly fragmented. The system was much peppier after I ran it.

I hope these steps will be helpful. It’s not as good as getting a new computer, but it’s much easier to live with now. If your system is bogged down, and like mine, it’s an old laptop that uses scarce and expensive memory and is out of slots anyway, this will make it easier to live with.

Optimizing Windows 2000

Dave Farquhar Windows , , , , , ,

Since there was no Windows 2000 version of my book Optimizing Windows, sometimes people ask me what tweaks they can use to improve Windows 2000’s performance.
It turns out there are a few things you can do to optimize Windows 2000. Here are some tips that I use on a fairly regular basis.
Read more

Sound card and hard drive troubleshooting

Dave Farquhar Troubleshooting , , , , , , , , , , , ,

Sound card woes. Gatermann recently ran into some problems with sound cards forcing his Internet connection to drop. It had literally been six years since I’ve seen a problem like that before, but he kept running into it. Finally, it dawned on me: Try changing slots to force it to use a different interrupt. Therein was the silver bullet. The problem didn’t go away completely, but the culprit arose: the Sound Blaster 16 emulation. So I had him go into Device Manager and put the SB16 emulation on a different interrupt, and the problem went away.
It’s been forever since I’ve seen an honest-to-goodness interrupt conflict. This particular PC has every expansion slot filled with something or other, which is why he ran up against it. Keep that in mind: Just because we have PCI and plug and play these days, doesn’t mean you won’t ever see an interrupt conflict. On a well-expanded system, this ancient problem can occasionally rear its ugly head (while Microchannel required their cards to be capable of interrupt sharing; PCI only *recommends* it–so not every PCI device can share an interrupt, particularly if an ISA device has grabbed it. Alas, Microchannel fell victim to IBM’s greedy overly restrictive licensing terms and raw-dead-fish marketing, so as a result we have cheap PCs today but more headaches than we necessarily need. Speaking of raw-dead-fish marketing, I could mention that the Amiga’s Zorro bus had true plug and play and hundreds of interrupts from Day One in 1985, but nobody wants to hear that. Oops, I said it anyway.)

This problem used to happen all the time when people would put their modems on COM4 and a serial mouse on COM2 (or COM1 and 3). Since those ports by default shared interrupts with one another, you got goofy symptoms like your Internet connection dropping whenever you moved the mouse. People don’t configure their COM ports that way anymore, which is what’s made that problem so rare.

I think I finally got that G4 deployed. Wednesday it decided it didn’t want to shut down, and I had to reinstall the OS to fix it. Then on Thursday, it decided it didn’t want to recognize the mouse button anymore. I still don’t know what exactly I did to fix that–I booted off a spare MacOS 9 partition, ran a battery of disk repair tools and a defragmenter, and the problem went away. So while Mac users can snicker about interrupt problems, their machines aren’t exactly immune to weird problems either.

——-

From: “Gialluca, Tony”

question: RE Optimizing Windows and Temp files

Hi Mr. Farquhar,

In you book on page 112 you discuss placing temp files on a ramdisk. On this page you show an example where:

Set temp=ram disk letter:\temp Set tmp=ram disk letter:\temp

Shouldn’t you also include changing

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Volum eCaches\Temporary files\folder] to “ram disk letter:\temp” also ??

Per the description

([HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Volu meCaches\Temporary files\description]) says: “Programs sometimes store temporary information in a TEMP folder. Before a program closes, it usually deletes this information.\r\n\r\nYou can safely delete temporary files that have not been modified in over a week.” The only potential pitfall that I can think of is if windows or programs (say during installations) need this area to remain persistant through reboots, even though the files may be of
a temporary nature…

Your thoughts would be appreciated …

Respectfully,

Tony

———-

To be perfectly honest, I didn’t know that registry key existed (nor did the book’s technical reviewers, evidently). That registry key, too, should be changed, yes. Thanks!

You are correct that if a program does a hard reboot (rather than just exiting to real mode and reloading Windows), you’ll lose the contents of the ramdisk and thus the temp folder. Fortunately, most programs seem to use the temp directory the way they’re supposed to–for temporary, fleeting things. Now if they’d just learn to clean up after themselves…

Of course, this also applies to my advice on creating a temp partition, on page 62.

Thanks much; this is very good information.

———-

From: “Gary M. Berg”

Subject: Maxtor hard drives

Since you’ve been talking about WD and Maxtor hard drives…

I heard rumors just after Win2K SP1 came out that the service pack had problems with machines with Maxtor hard drives. I’ve not been able to find much of anything else on this. What have you heard?

———-

That’s a new one to me. Maybe another reader has heard something, but it sure seems odd. I can’t imagine Microsoft didn’t test SP1 on the major drive manufactuers’ drives (Fujitsu, IBM, Maxtor, Quantum, Samsung, Seagate, and Western Digital), and with Maxtor being one of the Big Two in retail….

Once I get my current big project off my back this weekend, I’m half-tempted to try it just to see. Unless someone already has…

Tongue-tied

Dave Farquhar Windows , , , , , ,

Anything to say? My sister (yes, she has a name–it’s Di) mailed me and asked me if I had anything to say today. Not really. I finally won a major victory at work that will result in the departure of two Macintoshes that have become the bane of my existence. The battle came at a high personal price–I’m exhausted and have little to say. Other than an observation that AppleShare IP 6.3 appears to be about as rude as its predecessors. It seems to like MacOS 9, but it also seems very willing to crash MacOS 8.6 and earlier clients. Seeing as these are 100, 120, and 132 MHz machines, upgrading to 9 isn’t exactly practical or worthwhile or cost-effective. So they’re getting brand spanking new Micron PCs with Pentium III 600 chips or whatever it is we’re buying these days. I will be very joyfully installing them in the morning.

———- From: al wynn
Does McAfee still sell Nuts&Bolts?

Exactly how do you use Nuts&Bolts to “sort directory entries by the file’s physical placement on the hard drive” (ie. under which menu item can I find it ?)

Also, what are some good web links (or other resources) that will show me how to optimize Norton Utilities configuration ?

———-
It’s in Disk Tune. Click Advanced–>Directory Sort–>Sort Criteria. There you can select Cluster number as your directory sort criteria. Under Win95, this makes N&B’s Disk Tune the best defragmenter/optimizer, but under Win98, NU’s Speed Disk and Fix-It’s Defrag Plus have features that will make them outperform Disk Tune in spite of this feature (they actually do some strategic fragmentation to increase speed). I suppose you could optimize the disk with one of the others, then try to get Disk Tune to skip the defragmentation part and just optimize the directories, but I think I tried to figure out how to do that and gave up. Alternatively you could optimize with Disk Tune first, then defragment with one of the others and not do anything with the directory entries–assuming you want to save absolutely every microsecond possible. (Be aware that Disk Tune is a very slow program, so we’re talking diminishing returns here to run it, then run one of the others.)

I haven’t seen a better resource for the utilities suites than chapters 3 and 5 of Optimizing Windows; those chapters were the result of about seven years’ experience messing around with disk utilities (starting under DOS, of course). I’ve never seen a Web site on the subject (good or bad); nor much other information outside of the manuals that came with some of the older versions. That was part of the reason why I wrote my own. I tried to explain what to do with whatever suite you happened to have, as well as the reasoning behind it.

So, who makes the best Mac utility?

Dave Farquhar Macintosh , , ,

When it comes to Macintoshes, I feel like a catcher playing shortstop. Yes, a good athelete can play both positions, but very few can play both exceptionally well. The mindset’s all different. The ideal physique for each is all different.
I fix Macs for the good of my team. Period. Right now my job is to nurse along a dozen Macs for four months until the new fiscal year starts, then they can replace them. I think those machines have four months left in ’em. The bigger question is, do I have four months’ tolerance left in me? Hard to say.

But thanks to my pile of Macs on their last legs (these are 120 MHz machines with no L2 cache and a pathetic 10 MB/sec SCSI-II bus, and they’ve never had regular maintenance) I’ve gotten a lot of first-hand experience with Mac utilities suites.

I said in my book that Norton Utilities for Windows is, in most regards, the second-best utilities suite out there. Problem is, the other two big ones split first place, and the third-placer is usually so bad in that regard that you’d prefer not to use it. So Norton Utilities compromises its way to the top like a politician. The Mac Norton Utilities is the same way. There are two reasons to buy Norton Utilities for the Mac: Speed Disk and Norton Disk Doctor. Period. The rest of the stuff on the CD is completely, totally worthless. Eats up memory, slows the system down, causes crashes. Copy SD and NDD to a CD-R, then run over the original with your car. They’re that bad. But of course your end-users will install them since all software is good, right? You should install everything just in case you need it someday. Famous last words, I say…

But you need Speed Disk and Norton Disk Doctor desperately. Macs are as bad as Microsoft OSs about fragmentation, and they’re far worse about trashing their directory structures. Use a Mac for a week normally, and use a PC for a week, turning it off improperly on a whim (with automatic ScanDisk runs disabled), then at the end of a week, run a disk utility on each. The Mac will have more disk errors. Apple’s Disk First Aid is nice and non-invasive, but it catches a small percentage of the problems. NDD scoops up all of the routine stuff that Disk First Aid misses.

As for Speed Disk, it works. It’s not the least bit configurable, but it has enough sense to put frequently used stuff at the front of the disk and stuff you never touch at the end.

But if you need to do what Norton Utilities says it does, you really need Tech Tool Pro. Its defragmenter is at least the equal of Speed Disk, and its disk repair tools will fix problems that cause NDD to crash. Plus it has hardware diagnostics, and it’ll cleanly and safely zap the Mac’s PRAM (its equivalent to CMOS) and cleanly rebuild the Mac’s desktop (something that should be done once a month).

But the best disk repair tool of them all is Disk Warrior. Unlike the other suites, Disk Warrior just assumes there are problems with your disk. That’s a pretty safe assumption. It goes in, scavenges the disk, rebuilds the directory structure, and asks very, very few questions. Then it rewrites the directory in optimal fashion, increasing your Mac’s disk access by about the same factor as normal defragmentation would.

Oh yes, Disk Warrior comes with a system extension that checks all data before it gets written to the drive, to reduce errors. I really don’t like that idea. Worse speed, plus there’s always something that every extension conflicts with. That idea just makes me really nervous. Then again, since I regard the Mac’s directory structure as a time bomb, maybe I should use it. But I’m torn.

Which would I buy? If I could only have one of the three, I’d take Tech Tool Pro, because it’s the most complete of the three. I’d rather have both Tech Tool and Disk Warrior at my disposal. When a Mac goes bad, you can automatically run Disk Warrior, then rebuild the desktop with Tech Tool Pro before doing anything else, and about half the time one or the other of those (or the combination of them) will fix the problem. Or they’ll fix little problems before they become big ones.

Disk Warrior is positively outstanding for what it does, but it’s a one-dimensional player. For now, it does ship with a disk optimizer, but it’s limited to optimizing one of the Mac’s two common disk formats. At $79 vs. $99 for Tech Tool Pro, if you’ve only got a hundred bucks to spend, you’re better off with Tech Tool Pro.

As for Norton Utilities, I’ve got it, and it’s nice to have a third-string disk utility just in case the other two can’t fix it. Sometimes a Mac disk problem gets so hairy that you have to run multiple disk utilities in round-robin fashion to fix it. So run Disk Warrior, then Tech Tool Pro, then Norton Disk Doctor, then Apple Disk First Aid. Lather, rinse, and repeat until all four agree there are no disk errors.