How much free capacity has my 3Par got? This seems like a simple question but I see lots of questions about it in the forums and know I went round in circles trying to understand the 101 stats the management console throws at you when I first started with 3Par.
So the plan for today is too keep it simple. I’m going to show you two key places to look that should answer 90% of your 3Par capacity questions. We will focus on the 3Par Management Console first as it shows the figures in GiB which I think is easier to work with.
1 Physical Disk Space
Ok so let’s gets started. The first thing to understand is how much capacity has been consumed on the physical disks. This is simply as a percentage how full are the disks. The steps to find this are below
- Open up your 3 Par Management Console
- Select systems from the navigation pane
- Highlight the name of your SAN in the management tree
- In the management window choose the capacity tab.
It’s quite self-explanatory. The top of the windows shows the total for all the different types of disks in your system and then breaks this down by disk type below, this is then further broken down into allocated and free space. So for example the above screen shot shows the fast class disks are 88.51% full.
Next you want to know what’s gobbling up all that space. If you expand the disk class you are interested in you will see it then splits this into space used by the system v space used by volumes
You can keep drilling down further and further on an item. Like below, I’m looking at what proportion of the allocated space is taken up by the volume itself and how much is snapshot space. Have a play and you will get the idea.
Ok so now we know how much space is left on our physical disks but the key question is how much actual writeable space is left for critical stuff like the marketing department to store their pictures in. You can view this on a per CPG level.
2 CPG Space
This part deals with the question how much writeable space have I got left in the CPG.
- Open up your 3Par Management Console
- Select provisioning from the navigation pane
- Then from the management tree highlight CPG’s
- In the management pane on the top right highlight the name of the CPG you want to look at
- Choose summary in the bottom management pane
- The stat you are interested in is estimated free system space, shown in the bottom management pane
So the above screenshot shows that there is 10,387GiB of writeable space left on this CPG. Writeable space takes account of the amount of space consumed by raid parity, system space etc. and tells you how much space is actually available for volumes to grow into.
With the CPG space figures you need to be aware if you have other CPG’s on the same set of physical disks they will also be competing for the space. So for example in the above screenshot the 10,387GIB may not be for exclusive use by the CPG you are looking at. Also be aware that some CPG’s will consume space much faster than others, for example a raid 1 CPG will use up space much quicker than a raid 5 CPG.
If you are a command line junkie you can get exactly the same stats from the CLI. To view get a similar view of disk capacity utilisation as in part 1 run
showsys – space
To view writeable capacity left on a CPG as in part 2 run the below, the figure you are interested in is LD free
showspace -cpg cpgname
CPG —–EstFree—– ——Usr—— —Snp—- —Adm—-
Name RawFree LDFree Total Used Total Used Total Used
R6 15954816 10636544 2051840 2048000 0 0 0 0
Hopefully knowing these methods will allow you to manage the capacity of your 3Par system more easily