HP-UX Reference (11i v1 00/12) - 1M System Administration Commands A-M (vol 3)

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lvchange(1M) lvchange(1M)

-c mirror_consistency Set mirror consistency recovery. This option is effective only when -M n is

speciﬁed or previously set. mirror_consistency can have one of the follow-

ing values:

y Set mirror consistency recovery on. LVM achieves mirror consistency

during volume group activation by going through all logical extents

and copying data from a nonstale copy to the other mirror copies.

n Set mirror consistency recovery off. LVM does not perform mirror

consistency recovery on this logical volume when the volume group is

activated.

-C contiguous Set the contiguous allocation policy. contiguous can have one of the follow-

ing values:

y Set a contiguous allocation policy. Physical extents are allocated in

ascending order without any gap between adjacent extents and all

extents are contained in a single physical volume.

n Do not set a contiguous allocation policy.

A nonempty logical volume that has a noncontiguous allocation policy can-

not be changed to a contiguous allocation policy unless it happens to meet

all the requirements of the contiguous allocation policy. See lvcreate(1M)

for more information about the contiguous allocation policy.

-d schedule Set the scheduling policy when a logical extent with more than one mirror

is written. (The scheduling policy of a striped logical volume is striped and

cannot be changed.) schedule can have one of the following values:

p Establisha parallel scheduling policy.

s Establish a sequential scheduling policy. Use this value with care,

because it leads to performance loss in most cases.

-D distributed Change the distributed allocation policy. distributed can have one of the

following values:

y Turn on distributed allocation.

n Turn off distributed allocation.

f Force distributed allocation to be on.

When the distributed allocation policy is turned on, only one free extent is

allocated from the ﬁrst available physical volume. The next free extent is

allocated from the next available physical volume. Allocation of free

extents proceeds in round-robin order on the list of available physical

volumes.

When the distributed allocation policy is turned off, all available free

extents are allocated from each available physical volume before proceeding

to the next available physical volume.

The distributed allocation policy REQUIRES the PVG-strict allocation pol-

icy ( -s g ) to ensure that mirrors of distributed extents do not overlap

(for maximum availability).

The distributed allocation policy is incompatible with the striped scheduling

policy ( -i stripes ) and the contiguous allocation policy ( -C y ).

See lvcreate(1M) for more information on the distributed allocation policy.

The -D y option will fail if the existing logical volume has any two con-

secutive logical extents on the same physical volume. To override this

failure, use the -D f option.

If a logical volume with the distributed allocation policy has at least two

consecutive logical extents on the same physical volume, then

lvdisplay(1M) will display the allocation as partially-distributed

(vs. distributed ).

HP-UX Release 11i: December 2000 − 2 − Section 1M−−425

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