cpurn@cpurn.net (Christian Purnomo) writes: > Thanks, > > I have tried changing the partitions type to 0xFD and the auto > detects kicked in and LVM still worked like a charm. > > However I found this from mailling list archive > > /* start quote */ > > From: Luca Berra <bluca comedia it> > To: linux-lvm redhat com > Subject: Re: Re: putting lvm autodetect into the kernel ala md > Date: Fri, 1 Apr 2005 19:41:22 +0200 > > quote Neil Brown back in july 2001 > > "autorun/autodetect just doesn't belong in the kernel. It should be > done in user space. The only time the kernel should assemble a raid > array itself is for the root device, and this is best done with > md=0,/dev/whatever,etc > > If I could start with a clean slate, I would rip out the autodetect > stuff completely. But lots of people are depending on it so I cannot." > > anyway the major issues are: > 1) raid autodetect uses only the minor number stored in the superblock > to identify the array components, move a disk from a different machine > to yours and reboot it to enjoy the show Is this really true? My kernel log has messages like these: md: Autodetecting RAID arrays. md: autorun ... md: considering sdb3 ... md: adding sdb3 ... md: sdb1 has different UUID to sdb3 md: adding sda3 ... md: sda1 has different UUID to sdb3 md: created md2 If it uses the UUID, there should be little risk of misdetection. A problem I have run into with LVM, was disks from different machines, using the same VG names. > 2) raid autodetect will try to start everything it finds, it will not > scale with shared storage, or other complex configurations > > /* end quote */ > > Can anyone conclude that passing the parameter md=0,/dev/* to kernel > parameter is a better approach than using auto detect? I don't have > a problem with having a rather long parameters in my > grub.conf/lilo.conf. As usual, both ways have their own advantages and disadvantages. What I like about autodetection, is that things just work, even if I shuffle my disks for some reason. -- Måns Rullgård mru@inprovide.com _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
