LVM and VxVM
cancel
Showing results for 
Search instead for 
Did you mean: 

Alignment of vxfs filesystem in a LUN

 

Alignment of vxfs filesystem in a LUN

Hi,

I have hints that the mapping of blocks of a vxfs filesystem in a LVM lvol/vg is misaligned to the block mapping on my storage system.

So I need to know the physical layout of a vg/lvol/filesystem in a LUN. Is there a tool available to check the starting block of the filesystem in the LUN? How can I influence the starting block of a vxfs filesystem in a lvol/vg?

Other usefull hints for me to investigate further in this topic?

Thanks in advance for your help.

Best Regards
Walter
2 REPLIES 2
boukari
Frequent Advisor

Re: Alignment of vxfs filesystem in a LUN

Hi,
there are two kinds of LVM disk layouts, one for boot disk and other for others LVM disks.
bootable disk ( PVRA,VGRA, and a sector for BDRA)
non-bootable disk : has two area PVRA,VGRA
So,
Information about the LVM disk data structures in the BDRA is maintained with the lvlnboot and lvrmboot commands.

# lvlnboot -v
Check this link for more information:

http://docstore.mik.ua/manuals/hp-ux/en/5992-4589/ch01s06.html

To check file system there's 'fsck' (to check cohérence of your file system)
But i dont know about start block , and there's the syntax to check alla file system:

#fsck -F vxfs -o full /dev/vg??/rlvol??

***Running fsck on mounted filesystems is not recommended

I hope that helps you
Best regards,
BCS SW/HW GSC Engineer (L1)
IEEE Student Member
LPI 3 CORE & High Availability
VCP Vshpere 5 Datacenter
Novell CLA and Data Center specialist Certified
.....
Microsoft Partner & Microsoft student Partner
boukari
Frequent Advisor

Re: Alignment of vxfs filesystem in a LUN

Hi,
Sorry,
Please try to give us the output that u used to know that ur vxfs isn't aligned .And more about (fsck)
this command depend of ur HP-UX version, so try ( # uname -a )

#vgdisplay -v /dev/vg??
to check ur vg ?? configuration

# fsck -F vxfs -o full /dev/vg??/rlvol??

This command let to check ur vxfs
and there's an exemple of output:

"""""
#fsck -F vxfs -o full /dev/vgpd/lvexp
log replay in progress
pass0 - checking structural files
pass1 - checking inode sanity and blocks
pass2 - checking directory linkage
pass3 - checking reference counts
pass4 - checking resource maps
OK to clear log? (ynq)y
set state to CLEAN? (ynq)n
sanity checks/updates have not been completed - restart? (ynq)y
pass0 - checking structural files
pass1 - checking inode sanity and blocks
pass2 - checking directory linkage
pass3 - checking reference counts
pass4 - checking resource maps
OK to clear log? (ynq)y
set state to CLEAN? (ynq)y
#fsck -m /dev/vgpd/lvexp
vxfs fsck: sanity check: /dev/vgpd/lvexp needs checking
""""
best regards,
BCS SW/HW GSC Engineer (L1)
IEEE Student Member
LPI 3 CORE & High Availability
VCP Vshpere 5 Datacenter
Novell CLA and Data Center specialist Certified
.....
Microsoft Partner & Microsoft student Partner