Messages in this thread | | | Date | Thu, 15 Dec 2005 10:35:07 -0800 | From | Greg KH <> | Subject | Re: slow sync of fat 32 hotplugged devices |
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On Thu, Dec 15, 2005 at 07:28:09PM +0100, Patrick Fritzsch wrote: > Hallo, > I checked out suse10 lately and discovered some annoying behaviour in > hotplugging an USB Stick. > > It seems that the hal daemon mounts a usbstick in fat32 mode, where > default the sync option ist on. Actually this is a nice behaviour, > because a cp to the stick should last so long until the file was > completly written.
This is a HAL issue, just have it mount without sync enabled and your speed will return.
> Actually the performance is very bad. A 200 MB file needs around 10 > Minutes in sync mode, while it needs around 1 Minute in not synchronous > mode + executing a sync command later. > > I guess that the kernel checks after every block of the file, which is > written, if the stick has really written it, which leads to such a big > slowdown. There are already lots of comments of this in the web, where > the solution is always to disable the sync mode in the hal daemon device > files. > > Wouldnt it be a nice behaviour, if you could mount a file in a new sync > mode, where it isnt synchronized during writing a file, only when a > close ioctl command was executed on a filehandle? > sync writing to hotplugged devices would be a lot faster then.
Yes it would, and I'm pretty sure people are already working on this :)
But if you have some patches that enable this functionality already, please post them.
thanks,
greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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