Messages in this thread | | | Date | Fri, 14 Dec 2001 19:11:50 +0000 | From | Alasdair G Kergon <> | Subject | Re: A possible direction for the next LVM driver |
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On Thu, Aug 30, 2001 at 04:45:47PM +0100, Joe Thornber wrote: > I'm working on the next iteration of the LVM driver ...which is now known as the "device-mapper" because it lets you define new block devices that map I/O onto sections of other block devices.
> The main goal of this driver is to support volume management in > general, not just for LVM. The kernel should provide general > services, not support specific applications. eg, The driver has no > concept of volume groups.
The latest version being tested is at: ftp://ftp.sistina.com/pub/LVM2/device-mapper/device-mapper-0.90.02.tgz
The tgz file contains a CVS snapshot which includes patches against 2.4.16 and some documentation (and details for the CVS repository).
Currently there's a choice between an ioctl interface and a filesystem interface (dmfs).
Example ======= To create a "logical volume" that concatenates /dev/sdc1 with /dev/sdd2: [units used below are 512-byte sectors]
# cat > /tmp/lv1_table 0 1028160 linear /dev/sdc1 0 1028160 3903762 linear /dev/sdd2 0 ^D # dmsetup lv1 /tmp/lv1_table
With the filesystem interface and devfs, you could also create /devfs/device-mapper/lv1 by hand as follows:
# mkdir /tmp/dmfs; mount -t dmfs dmfs /tmp/dmfs # mkdir /tmp/dmfs/lv1 # cp /tmp/lv1_table /tmp/dmfs/lv1/table
Striping is also already supported (see documentation).
Alasdair -- agk@uk.sistina.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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