Striping

[Sanjiv Sharma_1]

Hi,

I have one L-3000/HP-UX 11i with XP512 disk array.

XP512 has four array group(AG 2-5, AG 2-6, AG 2-7, AG 2-8) for L3000, each arraygroup consists of 10 nos. 14 GB LUNS each. So total 40 LUNs.

I want to create two lvols ( lvol3 270MB of 20 luns and lvol4 220 MB of 16 luns) with striping.

I want them to stripe in the group of four luns in the order (AG 2-5, AG 2-6, AG 2-7, AG 2-8) with one luns each and then again continues striping for another four luns in the same order.

What should be the commands?

Thanks,
Raje.

[Sanjiv Sharma_1]

Sorry it should be 270 GB and 220 GB.

[Alberto Tagliaferri_1]

What you're trying to do is hardware stripping (XP, not HPUX, is going to manage it) so there is no LVM commands you can use to make it. Refer to XP administration tools, may be you have a PC conected to the XP with the proper sw(certainly there's a notebook inside XP from where you can do it). But any of these requires thorough undestanding of XP technlogoy (you can wipe out data on another system also conected to the XP, for instance).
Safest choice: get an HP engineer do it.

Alberto.

[Sanjiv Sharma_1]

Hi Alberto,

Thanks for your advice. But here I am doing HP-UX striping.

Enclosed pls. find the disks available to L3000. I think this will give a better understanding of the requirement.

Thanks,
Raje.

[Gerrit Beyken · Accepted solution]

Hi Raje,

i would recommend you to use distributed allocation Policy (which distributes the Logical-Extends of an Lvol on all the disk in a PVG in a round-robin-manner) instead of striping because as an HP CE told me this brings more performance on your disk-io.

For your situation i would do the following:
Create an VG on your Ldevs or extend an existing VG if you want.
Thats the way for a new VG:
- mkdir /dev/
- mknod /dev//group c 64
- vgcreate -p /dev/
- lvcreate -s g -D y -r N -L -n
- newfs -F vxfs /dev//r


Best regards

Gerrit Beyken

[hyun-seok kim]

Hi

1. Use xpinfo program and make map PV and AG
2. use PVG

[Alberto Tagliaferri_1]

sorry, thought you wanted to use XP capabilities to do the stripping.
I agree with Gerry and Kim. You can create an stripping LV (-i) o r distributed (-D).
I've created a distributed LV and ask for the stripes to specific disk in lvextend like this.
First create the LV empty
lvcreate -D y -s g -n lvxx vgxx
Now extend it over the disk you want (choose the one from every XP disk array or "array group"). Using your info (
lvextend -l 4 /dev/vgxx/lvxx /dev/dsk/c23t8d0 /dev/dsk/c23t9d2
/dev/dsk/c23t10d4 /dev/dsk/c23t11d6

Now add 4 more disks (the second of each array group using secondary path)
lvextend -l 8 /dev/vgxx/lvxx
/dev/dsk/c25t8d1
/dev/dsk/c25t9d3
/dev/dsk/c25t10d5
/dev/dsk/c25t11d7

And then the 3rd of each AG using primary path, 4th using secondary, ...

When you are done, do a vgextend over left disk pairs (ie. 4 first of each AG using secondary path, 4 second using primary path, ...) to get Alternate link.

Why didn't I keep it simple? Why alternate (now primary, then secondary, ...). UX uses the alternate link just in case primary fails, so 99% of time (where both are ok) you'll be using just on HBA (card in you server) instead of all you have.
Hope this is what you needed.
Regards,

Alberto.