Re: WRKDSKSTS and finding true disk space usage

Ah but they DO show as 139GB drives, you simply need the secret decoder ring to know the FC 59FD is a 139GB drive. :-) If you Google 59FD about the fifth link down will tell you "139 GB 15K (528 block size) small form factor SAS disk drive (IBM® i)" (if you google IBM 59FD it's the first link)

The 59FD is known as the 'CCIN' or 'Custom Card Identification Number' which includes much more than cards of course. That number in some cases matches the order feature code of the particular item but often does not. This is because the same CCIN can appear in multiple places which may require different mounting hardware. This drive is a clear example. It could be in a system unit, in a FC #5887 or on older systems in a FC #5802 all three of which require different sleds and thus the Feature Code you order is different. Meanwhile the CCIN often (though sadly not always) reports the same to IBM i despite the different location. IBM i on the other hand could not possibly care less about the mounting sled it merely wants to know the size and capability of the drive itself.

WRKDSKSTS has always shown available capacity not raw capacity which means adding them up will match WRKSYSSTS.

It IS confusing when you don't do this every day as some of us do. It's even more fun when some of your 59FDs report in with a different capacity than others do! This generally means there are multiple raid sets which happen to have different number of members.


- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 5/4/2018 9:41 AM, Matt Olson wrote:

Gotcha! I'm not sure why they don't show as 139GB drives in any of the screens. So you can see where the confusion is. The IBMi doesn't show physical drive details.

-----Original Message-----
From: DrFranken <midrange@xxxxxxxxxxxx>
Sent: Thursday, May 3, 2018 8:45 PM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: Re: WRKDSKSTS and finding true disk space usage

So having seen your WRKDSKSTS and WRKSYSSTS snaps and then going back to this math right from the start you get a #FAIL in math. 11 x 127 is 1397 not 1268 and the entire conversation was based on it! Oops!! In addition you added in the capacity of the hot spare drive for some unknown reason.

Now before I doff my Bus Driver cap and start leaving tire tracks, perhaps a lesson.

You actually have 139GB drives which we know from the Type of 59FD. With IBM i the drive size that appears in WRKDSKSTS is the AVAILABLE size after RAID loss is subtracted. So the 126835MB is the effective capacity when there is one RAID-5 set of 11 drives. The hot spare drive does not appear in WRKDSKTS when properly configured (as yours is) and does not count in the available capacity.

If you had 8 of these drives in a single RAID set then they would appear with 121GB of capacity each.

So it's really understanding of how RAID works on IBM i and providing the correct information up front to help get correct answers!


- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 5/3/2018 2:48 PM, Matt Olson wrote:

Does anyone know why WRKDSKSTS shows total ASP size as 1395GB when it should really be around 1268?

We have 11 x 127GB drives in RAID 5 which should equal about 1268. We also have one hot spare, bringing it to 1395.

Why would WRKDSKSTS show the hotspare as usable drive space??

Additionally, the percentage ASP used is off as well because of this.

Lastly, does the system incorrectly calculate total used disk space because of the recursive sym link in QOpenSYs that links back upon itself up to a depth of 10 times (therefore inflating QOpenSys consumed space by 10x)?

Thanks!