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Re: Thin provisioning - how can I see total allocated vs. av
Posted: Mon Sep 16, 2013 12:32 pm
by Architect
showspace -cpg * to be exact
Remember that the free space is being calculated from the general free space pool, which might be shared by multiple CPGs. So you can't always just add all the freespace values in this overview.
Re: Thin provisioning - how can I see total allocated vs. av
Posted: Wed Sep 18, 2013 12:54 am
by afidel
kherrmann wrote:One of the things that concerns me greatly about TP is if we get overzealous adding TP VVs. What if we have 25% free space on NL, and a customer asks for 10% of the total disk. Then another customer requests 20%. We know they are unlikely to use half the space they requested, so we are comfortable adding the next customer who requests an additional 10%. So, now, if they all max out the space they were allocated, we are now X% above our total capacity.
This isn't an issue when we still have space to grow in an array, as we would just add more disks, but when we are getting close to that ceiling, it gets scary.
How can we see the total potential for all the VVs we've allocated? That would be a useful stat to see just how overprovisioned we are.
One idea is to use a couple sacrificial LUN's, have your favorite tool fill them with random garbage and provision them from a CPG outside of an AO policy so they don't just fall to your lowest tier. Then as you are getting close to full you order new equipment and delete your sacrificial LUN's to buy you time until your new array arrives then use PeerMotion to start moving volumes off to the new array.