xref: /netbsd-src/external/gpl2/lvm2/dist/scripts/lvm2create_initrd/README (revision 56a34939419542e88b386b2229be7565f4f45461)
1*56a34939Shaadhttp://poochiereds.net/svn/lvm2/
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3*56a34939ShaadThis is the lvm2create_initrd script written by Miguel Cabeca, with some small
4*56a34939Shaadmodifications by myself.
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6*56a34939ShaadHere are some other requirements and tips for using it:
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8*56a34939Shaad1) this script uses busybox on the initrd image, hence busybox needs to be
9*56a34939Shaadinstalled when you create your initrd.
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11*56a34939Shaad2) Make sure /etc/lvm/lvm.conf is set up correctly before running this. In
12*56a34939Shaadparticular, if you're using LVM on RAID, make sure that you have a filter that
13*56a34939Shaadexcludes the RAID component devices (this may not be necessary with the latest
14*56a34939Shaadpatch by Luca Berra, but it doesn't hurt).
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16*56a34939Shaad3) This initrd image does not support modules. If you need to plug in any
17*56a34939Shaadkernel modules during the initrd phase, then you'll need to hand-modify the
18*56a34939Shaadimage.
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20*56a34939Shaad4) The generated initrd image supports an 'lvm2rescue' mode as well. If you add
21*56a34939Shaadthe parameter 'lvmrescue' on the kernel command line, it will run a shell at
22*56a34939Shaadthe end of the initrd 'init' script. This can be helpful when trying to fix a
23*56a34939Shaadcorrupt root volume or root LVM2 volume group.
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25*56a34939Shaad5) No userspace md tools are installed, so if you're using LVM on RAID, then
26*56a34939Shaadyou'll probably want to mark your RAID partitions as type 'fd' so that the
27*56a34939Shaadkernel will start them automagically (or hand-modify the image).
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29*56a34939Shaad6) I'm not sure if devfs will work with this or not. udev, however does work,
30*56a34939Shaadand is recommended. Because the dm-* devices use dynamically allocated major
31*56a34939Shaadand minor numbers, kernel upgrades and the like can renumber your devices. To
32*56a34939Shaadfix this, you need to run a 'vgscan --mknodes' prior to fscking and mounting
33*56a34939Shaadyour rootfs. Doing this with a static /dev creates a problem though -- you
34*56a34939Shaadwill be modifying the root filesystem before it has been fsck'ed. udev gets
35*56a34939Shaadaround this by mounting a ramdisk over /dev, but you'll probably need to add
36*56a34939Shaada startup script that creates devices in /dev. The lvm2udev script in this
37*56a34939Shaaddirectory is an example of such a beast.
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39*56a34939Shaad--
40*56a34939ShaadJeffrey Layton <jtlayton@poochiereds.net>
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