Philipp Thomas wrote:
On Wed, 15 Aug 2012 21:39:08 -0700, Linda Walsh
wrote: Um... are you trying you boot from a separate partition to a RAID or LVM based system and no file system is involved after boot?
Of cause a file system is involved after boot. On my work system it's lvm for the the disk management and xfs as file system for all partitions.
Cuz as near as I can tell, you are trolling.
Didn't you notice that I wrote "sw raid OR lvm"? nowhere did I say raid and lvm.
Oh -- you meant linux-based sw-raid. SW-raids are included in many Dell BIOS's, no-hardware is involved -- just SW -- and they work fine to boot off of. Of course, if your driver to run the RAID is IN a RAID partition that is only supported by the driver, you have a catch-22. But the same isn't true for booting with dm and lilo, since lilo just uses 'disk space' independent of a file-system. So it could boot from a dm-only system (no file system), which is what you seemed to think wasn't supported in lilo. So IF you have a file system like ext2 -- you can have an ext2-only based system, if you want, isn't that true? In fact, are their any file systems supported as 'linux file systems' (i.e. they have to be able to hold user/group permissions all the standard stuff). That you can't boot from and use exclusively as your file system? LVM and linux SW RAID are both virtual disk->physical-disk mapping programs. LVM can do RAID 0 and 1 but it's prime purpose was to manage 'volumes' as heterogeneous collections of physical devices that can be broken into arbitrary size, whereas LSRaid takes multiple homogeneous devices and maps them into 1 virtual disk (that is mirrored or interleaved, or whatever, depending on what RAID level is used). They are optimized for different use cases, but are still both ways of combining multiple physical devices into 'featured' virtual volumes. Lilo might have problems booting directly from a DM LV, if the LV wasn't all on the same device. Could grub boot without a file system? you can answer that you don't need that -- but you say you are going to use a file system. There is no requirement to use a separate, 'limited feature' file system to boot from in lilo, whereas at one point, grub wasn't able to support a boot & root on an advanced file system. It's rather like telling me that I need a FAT32 filesystem to boot from then I can boot to my real-file system. Doesn't that sound a bit ridiculous and unreasonable? How is that different in requiring ext2 in order to run an xfs-only system? My point (as indirectly as I expressed it) was that linux has no restrictions about what file system it boots from. Lilo supports that feature. Grub, at one point, did not (don't know about now). The fact that Grub didn't support the full linux file-system model should have been enough reason, alone to keep lilo an equally supported choice as grub, as it provides features that Grub does no (and note -- I am not suggesting it be an exclusive choice, but as near as I can tell, it can support booting from anything Grub can, but the reverse was (and may still be) NOT true. Saying you can't boot from a from a volume manager that needs OS support to properly emulate the virtual disk, is a reasonable constraint. But file systems have no such abilities -- they can only run in one partition (though it can be physically split -- that's done outside of the file system by other SW). The only requirement is I am asserting lilo needs is to have the kernel image on the same disk (NOTE: it may very well be able to boot from a RAID mapped device, but I haven't researched that, so I'm not claiming that). With or without a file system, lilo can start a kernel from a single disk image. However, Grub needs 'fullish' file system support, as it provides pre-boot access to the file systems - so it has higher requirements. To use something that is limited at the start should have been sufficient to keep a full-support bootloader in the primary-boot-loader group. It wasn't. As a result, XFS was tossed aside -- and many people still don't boot from XFS even though they use XFS for their other partitions. That's a black eye for Grub, that will only be recovered from when people stop using a separate filesystem for what would otherwise be an XFS-only system. But I *think* it is history now, and if I understand people correctly, XFS is fully supported as a boot file system (is that correct?)... so at this point it's only a historical event that can be learned from for those that remain open to learning. To those that don't, any mention of the topic, no doubt sounds like a grating noise. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org