Create LV with PVG strict distributed allocation

[avi28june]

Hi All,

I am trying to create a new LV with PVG Strict Distributed allocation policy with NO mirror. In current setup all such previous LVs are created with even number of PVs i.e. 2, 4, 6..etc(for PVG Strict Distrubted allocation). At the moment I have 5LUNs(PVs), so would like to know if it will be good practice to go for it with above policy with NO mirror. I know we can create it but not sure if it is a good practice.

Thanks,

Avi.

[Patrick Wallek · Accepted solution]

If you are not mirroring then there isn't much advantage to using the distributed allocation policy.  If you want striping I would just use the normal striping options.

However, since you mention that you have 5 LUNs you probably have a disk array of some sort.  How are those LUNs set up?  Are they already striped across several disks on the array itself?  Are all 5 LUNs part of the same disk group so they are using the same disks?

You really need to consider if striping across LUNs already striped on the disk array is a good idea.  There are instances where that can do more harm than good.

[avi28june]

Thanks for your reply Patrick. However as this is a cluster filesystem and we had instructions to follow earlier standard configuration, I made this LV out of 5 LUNs with PVG Strict distributed allocation.

Your views does make sense to me. Thanks again.