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author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/device-mapper/striped.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/device-mapper/striped.txt')
-rw-r--r-- | kernel/Documentation/device-mapper/striped.txt | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/kernel/Documentation/device-mapper/striped.txt b/kernel/Documentation/device-mapper/striped.txt new file mode 100644 index 000000000..45f3b91ea --- /dev/null +++ b/kernel/Documentation/device-mapper/striped.txt @@ -0,0 +1,57 @@ +dm-stripe +========= + +Device-Mapper's "striped" target is used to create a striped (i.e. RAID-0) +device across one or more underlying devices. Data is written in "chunks", +with consecutive chunks rotating among the underlying devices. This can +potentially provide improved I/O throughput by utilizing several physical +devices in parallel. + +Parameters: <num devs> <chunk size> [<dev path> <offset>]+ + <num devs>: Number of underlying devices. + <chunk size>: Size of each chunk of data. Must be at least as + large as the system's PAGE_SIZE. + <dev path>: Full pathname to the underlying block-device, or a + "major:minor" device-number. + <offset>: Starting sector within the device. + +One or more underlying devices can be specified. The striped device size must +be a multiple of the chunk size multiplied by the number of underlying devices. + + +Example scripts +=============== + +[[ +#!/usr/bin/perl -w +# Create a striped device across any number of underlying devices. The device +# will be called "stripe_dev" and have a chunk-size of 128k. + +my $chunk_size = 128 * 2; +my $dev_name = "stripe_dev"; +my $num_devs = @ARGV; +my @devs = @ARGV; +my ($min_dev_size, $stripe_dev_size, $i); + +if (!$num_devs) { + die("Specify at least one device\n"); +} + +$min_dev_size = `blockdev --getsize $devs[0]`; +for ($i = 1; $i < $num_devs; $i++) { + my $this_size = `blockdev --getsize $devs[$i]`; + $min_dev_size = ($min_dev_size < $this_size) ? + $min_dev_size : $this_size; +} + +$stripe_dev_size = $min_dev_size * $num_devs; +$stripe_dev_size -= $stripe_dev_size % ($chunk_size * $num_devs); + +$table = "0 $stripe_dev_size striped $num_devs $chunk_size"; +for ($i = 0; $i < $num_devs; $i++) { + $table .= " $devs[$i] 0"; +} + +`echo $table | dmsetup create $dev_name`; +]] + |