filling ssd with storage disks Dell Compellent SC4020

I have in mind that 6 disks are the minimum for beginning a new tier. Its a RAID5-5 plus one Hotspare. But you should check this with your Dell Sales Rep!

Notes:

• Dell SC4020 introduced in 2014... spending $$$$$ in an old system isnt that smart
• A Compellent only accept Dell Compellent certified disks... no white labeled or something like Samsung Pro. I doubt that Dell will offer disks for the 4020
• Depending on your SCOS version the drives needs a max. FW version for support reasons
• A SC4020 is licensed on disk count. The base license always include 42 disk. If you under that than its not a problem
• For Dataprogression a extra license is needed otherwiese you will have 2 independent tiers
• A upgrade or adding capacity have always to be planed within the Compellent Quote Center when it comes to 4020,5020 and so on

With SCOS 7.3 the distributed Hotspare was introduced. A cold spare can only realized when placing a Disk in the unmanged folder or when placed under your desk. Again.... IIRC you need 6 disk so this will not work in your case.

Regards,
Joerg

It is possible to buy ssd drives for a relatively low cost. It turns out that the minimum is 6 disks, right? 5 pieces for organizing a level 5 raid + 1 for hot swapping? About Dataprogression, because. I don’t have support for my storage, how can I find out if it is enabled for me by indirect signs, can I somehow find out through the control program?

The existing licenses can be shown when you right click your SC within Dell Storage Manager client and then the "licensing" tab (see screenshot)

SC licensing

If you dont have DataProgression your tiers are independed and dont work together... so 2 "pools" instead one. In your case you have a dedicated SSD "pool".

I have take a quick look into my SC4020 book and on page 1-16 they only mentioned that for a RAID5-9 at least 9 disk are needed. On page 1-32 the start configurations are listet and they contain 6 disks as a minumum.
The reason why ia am not sure about is that we once added a new tier to a SC2020 and we also ordered the minimum disks as mentioned in the docs and at the end we cant enable the new disks because we are one disk short. Because youre limited on free disk slots you have to be sure that 6 disks will work.

Just to be sure.

1. Every non Dell SC disk will not work
2. Every used Dell SC disk will not work at first if it was not properly removed from the previous system. The support is needed to change the status of that drive

Regards,
Joerg

Well, with the progressive date, everything seems to be in order, please see the screenshot.
About disks. they will be new, not refurbished, if that's what you mean!
Of course, I'm confused, I have nowhere to find out what is the minimum of ssd drives specifically for my system. Tell me, you mentioned that you encountered a problem on sc2020, and how many ssd disks did you install?

In 2019 we added 6x10K Disks to a SCv2020 which already have 10x960G SSD(AllFlash)  and where unable to add the Disks into a manageble folder. We ordered one more and than we are able to get it working.

I will ask my TSR and will report shortly.

In all other cases we add completly filled JBODs or 11 Disks (SC30x0/50x0 have 30 Slots compated to 24) when expanding existing SCs.

Regards,
Joerg

I expect, I will be grateful to you for any information!

I have two types of disks. 1. 11 disks of 1 TB, 7200 rpm. 1 drive in hot spare. 2. 7 disks of 300 GB, 15,000 rpm, one of them in a hot spare. Accordingly, two levels. Tier 1 and Tier 3. A little later I will give a screenshot.

about disks with 15 rpm ... well, they configured it for my task at one time, it was a long time ago, in 2017, maybe then these were the best practices, I don’t know :))) I’m attaching a screenshot of how storage is now distributed by levels .

Ah OK... so for my understanding your new layout would look like

Tier1 = Your new SSD (your fastest)
Tier2 = Existing 15K Disks (everthing between the fastet and slowest)
Tier3 = Existing 7.2K Disks (your slowest)

Funny to see that you have 7x15K Disks and not only 6.

Regards,
Joerg