I have 3 computers(2XP and1Vista) networked together. Each of these computers have multiple external HDD's connected to them through powered USB hubs. The problem is that these ext. hdd's often go missing. that is the computer no longer sees them and they do not show up as electronically connected to the computer. All of the ex. hdd's that do this are known good devices because I can swap them out to another computer in my system and they show up as drives in the swapped to computer and work. Until I end up re-booting the swapped to computer and sometimes they show up and sometimes they don't. I can do the old hard re-boot(on/off/on) and sometimes the reluctant drives will come back, sometimes they won't. And sometimes this maneuver ends up crashing the OS requiring another re-boot. Since I know that all of the ex. hdd's are good and all of the powered hubs are good (as I said, I can swap drives to different computers(different hubs) and I can usually get them recognized by the new set up) I'm stuck thinking that the OS's (at least the part that identifies devices on the usb bus) is at best poor. Is there some sort of software command that I could use to "force" these 3 computers to "see" all of the devices on the bus? I know that these "missing" hdd's are detected somehow because if I run mounting software (maxblast or WD diagnostic) these programs will see the missing hdd's and ask if I want to formate them! But all of the data is there and the master boot records are good because, as I've said, if I connect them to another computer they (mostly) come up fine. I'm out of ideas, anyone else have this problem? Thanks for reading my post.
your diagnostics is confusing. some work and then they dont work and then when you switch to another computer they mostly work but maybe sometimes dont. yeah do you see what i mean? one question, did this setup of yours work before without any of these problems or did you just set this up recently? you may want to connect as many of your hdd's up to your computers without the hub and see the results. in other words remove the hubs out of the equation to rule them out. this time around keep track of your drives and how they behave as you get closer to figuring out the problem. give them numbers if you have to and write down notes if you have to. check behavior by connecting them to all the hubs and even to just the pc and also give them enough time to hibernate before checking. disable the turn off hdd option in power settings to see if that makes a difference. its possible that they are shutting off and not coming back on when there is a request sent. this accompanied by what you were saying when you needed to turn off/on again. this is all i can think of at the moment.
Well, you are right that the problem is confusing. You know that the hardest problems to solve are intermittent ones. I can't see how power settings on the computer could be a cause here as all of these problem ext. hdd's are connected through powered usb hubs. And they all have their on power supplies. As I said, these problem hdd's seem to be intermittent in the sense that if they don't work on one computer they will likely work on another one. I suppose that the individual "bad drives" could be the problem if they have bad or intermittent electronics on the drive itself. I'm certainly not a engineer, but I imagine that during the boot up process the OS "poles" the usb bus and the electronics on the drives have to respond and communicate to the OS. See, it seems, once the OS on a computer doesn't "see" a device on the usb buss, then it seems to mark it as "missing" and seems to "remember" that designation. Maybe I'm over thinking this. Is there a way to tell the OS, after boot-up, to re-poll devices on the buss and to not "remember" which ext. drives that it marked as bad? This problem only occurs on external usb drives, the computers always "see" internal drives. Thanks very much for your reply.
just reading up i found that most external hard drives have a built in sleep function in them. i recall how after leaving my external on idle for a little while i have to wait a few seconds for it to spin up before accessing it again. im thinking the turn off hard drive function in windows power settings must be for the internal hard drives. anyways i don't know if this is whats causing your issue. my advice was just to use process of elimination to at least narrow it down or find the source of the issue. "Is there a way to tell the OS, after boot-up, to re-poll devices on the buss and to not "remember" which ext. drives that it marked as bad?" i dont know a conventional way of doing this but if you uninstalled/reinstalled the usb port in device manager i'd imagine this would do it.
Really? Never knew that Wish i could shine some light on the issue, but i'm posting to inform you that i have the same issue with my WD Passport, connected to Windows 7. I can tell you for sure that the Power Option under Windows is not to blame. Reinstalling chipset drivers didn't help either. I thought it might be faulty usb ports, but that's not it either because when i plug in my 1gb usb flash drive, windows detects it almost instantly. Here's the kicker: when i use my external on a friends computer (mac laptop or pc), both detect the drive. So... if the issue is not with your usb ports and not with the drive... what could it be? This is where i stand and where you chazz also probably do. Personally, i think it's a motherboard malfunction.
Well, "IT" has struck again. I fired up the computers (all three) this morning, did Little computing', shut 'em down for a quick trip to the gym, fired 'em all up again and the Vista computer now only sees 5 external hdd's, whereas this morning and for the last 3 weeks, it "saw" 6. Located the bad boy and could not get it to come up now way no how. Un hooked it from the Vista computer, hooked up to the second XP computer and, voilà!, came up just fine on that computer. This is getting tiring. Just a thought, the OS's in the XP and Vista computer should be OK whether the drive is a PATA or a SATA type, right? There's got to be some way to tell the OS to go back and poll the usb devices again. Thanks for your responses.
i have 3 externals myself and never experienced these issues. if being on xp is to blame then that is yet another reason why i'm glad to still be on xp.
The Vista computer acts the same as the XP computers, don't have a Win7 computer. But now I'm really confused- the ext. hdd's that quit on the Vista drive, was transfered to the 2nd XP drive has not quit on the 2nd XP drive. So maybe these "failing" drives have problems in their own electronics and are "weak" and are on the verge of dying, and that's the reason they are so intermittent. I'm grasping at straws here, but who knows?
