lvm2 - update?

[helasz]

I am using TC 4.7.7 in a NAS with raid+lvm2 extensions. When executing pvcreate on appr. 5.5 TB raid5 array I get the message:

/dev/md127: pe_align (24576 sectors) must not be less than pe_align_offset (8388607 sectors)
/dev/md127: Format-specific setup of physical volume failed
Failed to setup physical volume "/dev/md127"

Search on the TCL forums and google have not given any meaningful result.
Back to 2010 on a mailing list (https://lists.fedoraproject.org/pipermail/users/2010-March/368333.html) it is stated pvcreate may fail on large RAID1

Since the lvm2 extension of TCL 4.x originates from Februar 2011 (I tried to reompile myself, but have not succeeded /libudev shows issues/) I am not sure whether this issue has been solved in the meantime in LVM2 itself or I can set the pe_align parameter on commandline (man pages are not clear to me in this sense) and get rid of the error message.

Would lvm2 be updated for TC 5.x?

Any help would be appreciated.

[helasz]

I found the solution. I did set the following variables in lvm.conf:

data_alignment_detection=0
data_alignment_offset_detection=0

I am still unsure how to do the same from command line, but it is does not bother me.

[Rich]

Hi helasz
This might provide some useful information for setting up raid/lvm2:
http://www.mysqlperformanceblog.com/2011/06/09/aligning-io-on-a-hard-disk-raid-the-theory/