Messages in this thread | | | From | Ed Cashin <> | Date | Tue, 2 Oct 2012 17:50:55 -0500 | Subject | Re: [PATCH 4/7] aoe: make dynamic block minor numbers the default |
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On Oct 2, 2012, at 5:17 PM, Andrew Morton wrote: ... >> The static arrangement is still available with aoe_dyndevs=0, and >> the aoe-stat tool from the userland aoetools package, the user >> space counterpart to the aoe driver, recognizes the case where >> there is a mismatch between the minor number in sysfs and the >> minor number in a special device file. > > Oh. There we are. > > Again, what are the back-(in)compatibility issues which users might > encounter with this?
I think the people who care about aoe_dyndevs=0 are the people creating an initramfs without udev and with AoE targets that have low shelf and slot numbers for addresses.
They might want a tiny bzImage that can boot off AoE storage using device nodes prepared in advance with mknod. The old static mapping is a nice fit for that use case.
There could be others with a reason not to use udev, but none of those others have ever communicated with me, if they exist.
It's probably confusing the way I did the commits, making static the default before explicitly changing it to dynamic, but usually the people who actually care about this are so technical that I expect them to read the git logs, and I wanted to leave a paper trail there for anyone reading later.
-- Ed Cashin ecashin@coraid.com
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