HPE Storage Users Group

Guys,

I've just started working with 3PAR in the last month or two, and obviously keeping your eye firmly on available space is paramount.

We have two CPG's configured in our environment, and I have been examining their usage with the showspace command.

cli% showspace -cpg SSD_*
-------------------------------(MB)--------------------------------
CPG -----EstFree----- --------Usr-------- ------Snp------ -----Adm----- -Capacity Efficiency-
Name RawFree LDFree Total Used Total Used Total Used Compaction Dedup
SSD_38 34965504 29137920 105246592 105246592 1131648 739712 245760 233472 3.5 1.4
SSD_19 20299776 16916480 109492992 109492992 4447488 4308992 165888 147968 2.0 -

So what I'd like to know is, for the purposes of understanding available usable space....

are my two CPG's completely separate, and not drawing from the same pool of raw space? So, in reality I could store an additional 29TB on SSD_38, and SSD_19 would go along fine still with 16TB of usable, available space?

many thanks....

Normally the two would share the same space on the same media (SSD's), but it will depend on whether you have a filter on the CPG's. Raw space looks to differ between the two which would tend to suggest there is a filter in place cli% showcpg -sdg would show this. Assuming that's the case and you've filtered each disk to a single CPG only, then each would have dedicated capacity - similar to a traditional pool.

thanks John.... here's the output from showcpg...

cli% showcpg -sdg
------(MB)------
Id Name Warn Limit Grow Args
1 SSD_19 - - 65536 -t r5 -ssz 6 -ss 64 -p -devid AREA1920S5xnNTRI,DDYE1920S5xnNMRI,DOPE1920S5xnNMRI -devtype SSD
0 SSD_38 - - 65536 -t r5 -ssz 6 -ss 64 -p -devid DOPM3840S5xnNMRI -devtype SSD


So its possible to have CPGs sharing the same physical disk pool, or to have them seperate from one another? and mine are seperate?

The default is for all CPGs to share the same disks of a devtype (SSD, FC, NL). Someone has added advanced filters to those CPGs to split the 1.92TB SSDs (3 different models) and the 3.84TB SSDs (1 model).
They may have been bought for different customers/depts. or they just wanted to make sure the usage of each SSD is evenly distributed (shared drives with large size differences in the same CPG can lead to the smaller ones filling up before the larger ones and then all new writes going to only the larger ones).
One thing to watch out for is that if you add any additional drives (either size) which are a different model you won't be using those drives from those CPGs until the filter is updated (or the space runs out).

aha I see..... many thanks guys