Viewing Free Capacity in 3Par

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

 

capacity 2

 

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.

Command Line

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

     ————————-(MB)————————–

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

 

To stay in touch with more 3PAR news and tips connect with me on LinkedIn and Twitter.

 

 

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7 thoughts on “Viewing Free Capacity in 3Par

  1. As a storage admin, I am a big fan of 3Pars. This said, I must confess that guessing free space is tricky as hell, specially on thin provisioned environments.

  2. Hi, great articles and easy to understand. I was hoping you may have information on the ‘CPG Growth Warning’ for AO? I am having a difficult time understanding if the CPG Growth warning should use the ‘CPG logical disk size’ or the ‘physical raw disk size’. The CPG size is much smaller to account for the RAID 6. Thank you in advance.

    1. Hi thanks for the feedback.

      As this alert relates to the CPG you would use the CPG space. Have a look what the total useable space is for the CPG and then set the warning as a proportion of this.

      1. Hi, thank you for your reply. The total usable space for the CPG is that the ‘Allocated Space’ value directly below the ‘CPG Growth Warning’ on the image of the CPG Details?
        Just wanted to confirm I am checking the correct value for ‘total CPG space’.

  3. Allocated capacity = includes usable space, snap space, admin space( raid protection)

    reserved space = includes spare chucklets?

    system space=?

    1. I assume you mean Virtual Volumes. This is because pre server 2012 when data was deleted it did not actively pass back the message to the SAN that data had been deleted. You needed to use utilities like sdelete to force the write of zeros.

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