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On Sat, 25 Jun 2016 22:18:39 +0200, Helmut Jarausch |
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(jarausch@××××××.be) wrote about "Re: [gentoo-user] booting - I don't |
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anystand how the (Linux) world works anymore" (in |
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<pIgoU9n+PTyazMfaAjTflI@P0zLLCmfwy+atNuDbwD3I>): |
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> On 06/25/2016 09:39:32 PM, David W Noon wrote: |
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[snip] |
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>> I always statically link the driver that operates the controller |
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>> that connects the root device and modprobe the drivers that |
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>> operate the other disk controllers. This ensures that the |
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>> controller for my /dev/sda device is probed first and its drives |
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>> get "a", "b" and "c" in /dev/sd?, and those letters are assigned |
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>> in device address order on the controller. |
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> |
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> Thanks Dave, but I do statically link the corresponding device |
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> drivers, as well. |
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|
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I should have been more clear: only 1 driver for disk controllers |
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should be statically linked; the others should be modprobed, usually |
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by naming them in /etc/conf.d/modules. |
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> But I don't understand why my only hard drive is named sdb? |
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Another drive, presumably on another controller, has been hardware |
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probed first. |
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|
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The reason I use a mixture of static and dynamic linking is to control |
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the sequence in which the hardware probes are run. If you statically |
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link everything, the kernel can have the drivers run their hardware |
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probes in whatever order it chooses. When they are dynamically linked, |
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the hardware probes occur in the sequence in which the modprobes occur. |
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|
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The upshot is that the drives controlled by statically linked drivers |
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are probed first, then the drives controlled by dynamically linked |
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drivers are probed in the order in which the modprobes occur. |
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Therefore, I configure my kernels so that the drives get probed in the |
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order I want. |
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> It looks as if my kernel named my built-in CDROM device as /dev/sda |
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> . |
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An optical drive should be /dev/sr0 or the like. Are you sure it's the |
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CD-ROM drive grabbing the hard drive address? That seems like |
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something the old IDE drivers used to do; if you are using the long |
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obsolete IDE kernel modules, you should really upgrade to the libata |
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drivers. |
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|
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> And if I have plugged in an USB drive it seems to influence the |
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> naming scheme, as well. |
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|
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Your USB controller's driver appears to be statically linked. This is |
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a seriously bad idea. |
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> And, to make it even more complicated, once the system is up, it |
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> has a different naming scheme. E.g. now my internal hard disk has |
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> the name /dev/sda but if I tried to boot by this name it fails. |
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That could well be udev/eudev renaming devices during its start-up. |
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> For a normal human as me, this is just crazy! |
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Well, Gentoo was never meant for normal humans. ... :-) |
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- -- |
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Regards, |
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|
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Dave [RLU #314465] |
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*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* |
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dwnoon@××××××××.com (David W Noon) |
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*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* |
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