[linux-lvm] lvextend for striped volume extension

[shlim]

Hi !

I am LVM user.

I have question.

Current LVM version support the lv extension for STRIPED VOLUME ??

[Heinz J . Mauelshagen]

Post by shlim
Hi !
I am LVM user.
I have question.
Current LVM version support the lv extension for STRIPED VOLUME ??

LVM1 is limited: you can't extend a stripe beyond a physical volume.

Give LVM2 a try which doesn't suffer from this constraint unless
you stay with the LVM1 ondisk format.
--
Regards,
Heinz -- The LVM Guy --

*** Software bugs are stupid.
Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen Sistina Software Inc.
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FAX 924446
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[Alasdair G Kergon]

Post by Heinz J . Mauelshagen

Post by shlim
Current LVM version support the lv extension for STRIPED VOLUME ??

LVM1 is limited: you can't extend a stripe beyond a physical volume.
Give LVM2 a try which doesn't suffer from this constraint unless
you stay with the LVM1 ondisk format.

And when using the new metadata format in LVM2, 'lvextend' accepts the
same stripe parameters as 'lvcreate'. If the number of stripes and/or
stripesize aren't given, it uses the values used by the last segment
of the existing LV.

A simple example:

lvm> lvcreate --stripes 3 --extents 12 vg1
lvm> lvextend --stripes 2 --extents +12 vg1/lvol0
lvm> lvdisplay --maps

--- Segments ---
Logical extent 0 to 11:
Type striped
Stripes 3
Stripe size 32
Stripe 0:
Physical volume /dev/sdb1
Physical extents 0 to 3
Stripe 1:
Physical volume /dev/sdb6
Physical extents 0 to 3
Stripe 2:
Physical volume /dev/sdb7
Physical extents 0 to 3

Logical extent 12 to 23:
Type striped
Stripes 2
Stripe size 32
Stripe 0:
Physical volume /dev/sdb1
Physical extents 4 to 9
Stripe 1:
Physical volume /dev/sdb6
Physical extents 4 to 9

And you can still specify a restricted list of PVs in the VG to use:
lvm> lvextend --stripes 2 --extents +12 vg1/lvol0 /dev/sdb6 /dev/sdb7

Alasdair