Grant Taylor wrote: > On 1/1/20 5:09 PM, Dale wrote: >> Howdy, > > Hi, > >> As some may recall, I have a 8TB external SATA hard drive that I do >> back ups on. Usually, I back up once a day, more often if needed. >> Usually I turn the power on, mount it, do the back ups, unmount and >> turn the power back off. Usually it is powered up for 5 minutes or >> so. When I unmount it tho, I sometimes notice it is still doing >> something. I can feel the mechanism for the heads moving. It has a >> slight vibration to it. Questions are, what is it doing and should I >> let it finish before powering it off? I'd assume that once it in >> unmounted, the copy process is done so the files are safe. I guess >> it is doing some sort of internal checks or something but I'm not sure. > > There might be some activity for up to 30 seconds after umount > finishes and returns to the command prompt. > > Note: umount will normally block until buffers are flushed to disk. > >> Is it safe to turn it off even tho it is doing whatever it is doing? > > I wouldn't. > >> Should I wait? > > I would. > >> Does it matter? > > Maybe. > > Is the drive SATA connected or USB connected to the machine? > > In some ways it doesn't matter. You can tell the kernel to eject the > drive. Once that finishes, there is no active remnants of the drive > in kernel. 5–15 seconds after that and you should be quite safe to > power the drive off. > > echo 1 > /sys/class/block/$DEVICENAME/device/delete > > That will cause the kernel to gracefully disconnect the drive. > >> Thanks. > > :-) > > >
It is connected with a eSATA cable. It has a USB connector as well but I just don't trust USB as much as I do SATA. Other USB enclosures had "issues". ;-) If I touch the enclosure and feel it doing something, I leave it on, just in case. I actually been wondering about this for a while. Sometimes it will stop after a couple minutes, sometimes it is still doing its thing 30 minutes later. In the case of the first, I was concerned about files being cached etc. Thing is, it *should* do that before unmounting. In the case of it going on for 30 minutes or more, I was wondering if it was doing some sort of housekeeping, media tests or something. I just didn't know if it was important to wait or not. On occasion I would leave the drive on overnight or all day. I figure it would be able to at least do a quick self test and report errors if any. Thanks for the extra info. It helps a bit. Dale :-) :-)
