Messages in this thread | | | Date | Mon, 7 Jan 2008 10:39:13 -0500 (EST) | From | Alan Stern <> | Subject | Re: [linux-usb-devel] [FEATURE REQUEST] Transparent hot plugging of root file system on portable storage devices. |
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On Sun, 6 Jan 2008, Pavel Machek wrote:
> On Sun 2008-01-06 17:26:17, Alan Stern wrote: > > On Sun, 6 Jan 2008, Oliver Neukum wrote: > > > > > Am Sonntag 06 Januar 2008 schrieb Alan Stern: > > > > What about people who want to suspend to RAM instead of hibernating and > > > > _do_ want to unplug the USB device containing their root filesystem > > > > while the machine is asleep? > > Ok, I guess I'm lost here. That sounds like a nice way to do > self-leg-shooting. Are there such people?
Yes. People with small systems having extremely limited rw storage (no swap space), using removable read-only media as their root fs.
You can find the thread leading up to this request here:
http://marc.info/?t=119544588400002&r=1&w=2
> > > Would it be hard to force the persist feature on for a replugged device? > > > > Right now the persist feature is enabled by a per-device boolean flag. > > In theory the flag could accept 3 values: off, on if power was lost, > > or on for any resume transition. This would not be a hard change. > > But do we need it?
That depends on whom you ask! :-)
> Did you progress on "usb-storage-autosuspend"?
Yes; the first round of patches will be posted later today.
> Here are my hacks to try to get SATA to survive autosuspend; > unfortunately they do not work :-(.
You should start off with minimal support for manual runtime suspend (through a sysfs attribute). When that's working, autosuspend will be easier to add in.
Alan Stern
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