Storage Boards Cleanup
To make it easier to find information about HPE Storage products and solutions, we are doing spring cleaning. This includes consolidation of some older boards, and a simpler structure that more accurately reflects how people use HPE Storage.
cancel
Showing results for 
Search instead for 
Did you mean: 

12h Autoraid

N/A

12h Autoraid

I know the way how to get good performens.
The way is:
1) Create each vg comprised of 2 LUNS of equal size. LUNa should be primary path controller X (alt Y); LUNb should be primary path controller Y (alt X). This utilizes both external SCSI paths for maximum performance.
2) Each lvol should be striped across both LUNS in the volume group for the same reason.
3) As you indicated, run them at about (50-60%) capacity leaving the remainder as unconfigured LUNS. Yes, you waste disk but the performance is worth it.

But my question is must be the 2 LUNS in the vg of equal size?????
Thanks
3 REPLIES
Bill McNAMARA_1
Honored Contributor

Re: 12h Autoraid

for striping, yes.

You'll hear two schools tell you about the + and - of striping. The expert center will tell you it really makes no difference at all if you stripe or not as the autoraid does this anyway, and others will tell you it does..

In the end of the day, it really makes not much of a difference.. at least in my tests.. athough it doesn't cause any harm either!

Later,
Bill
It works for me (tm)
Bill McNAMARA_1
Honored Contributor

Re: 12h Autoraid

for striping, yes.
(adding to this! wonder if that submit worked!!)

the striping is done at the logical volume level, so make sure the lv's are the same size:
lvcreate -L 5000 -i 64 -I 2 /dev/vg00
5G must be free on each of the 2 PVs in the VG.

Now if the LUN (ie the PV) is not the same size, contiguous LV issues and striped LV additions may not be possible.


You'll hear two schools tell you about the + and - of striping. The expert center will tell you it really makes no difference at all if you stripe or not as the autoraid does this anyway, and others will tell you it does..

In the end of the day, it really makes not much of a difference.. at least in my tests.. athough it doesn't cause any harm either!

Later,
Bill
It works for me (tm)
A. Clay Stephenson
Acclaimed Contributor

Re: 12h Autoraid

The LUN's should be the size so that it's possible to stripe across both LUN's for all the LVOL's in the VG and ultimately use all the blocks in the VG.

Yes, the AutoRAID's automatically stripe across the disks - and you have no control over that other than how much space you leave unconfigured - but this striping refers to the external SCSI connections and you have total control over that.

The idea is to fully utilize the two external HVD SCSI buses so that the array can fully utilize its four internal SE SCSI buses.
If it ain't broke, I can fix that.