DS8000 model comparison: capacity, ports and features

You’ll play detective here. The practice shell is a DS8000, but which model? You’ll work that out from its own output, measure how much of the model’s limits it already uses, and then run a small sizing tool for a new project.

Practice shell note: the practice shell is our teaching tool, not IBM software. It behaves like a DS8A50 at Release 10.1. Real DS CLI output looks very much like this but is not identical. The sizing script is a planning tool that runs on your laptop; a DS8000 never runs your Python.

1Start clean

Open PowerShell (or Terminal), go to your lab folder and log in to the practice shell, then reset it so everyone starts from the same factory state.

Run this:

cd C:\ds8k-lab
python ds8sim.py
dscli> simctl reset

You should see this:

SIM0100I simctl: factory state restored (users and passwords kept; use simctl reset -all to reset them too).

✅ Checkpoint: the shell prints SIM0100I and the dscli> prompt is back.

2Read the model from showsi

Run this:

dscli> showsi

You should see this (output shortened):

Date/Time: 24 October 2026 19:50:21 UTC IBM DSCLI Version: 7.10.10.348 DS: IBM.2107-78SV001
Name             ds8k-g10-lab
desc             SaatVedha practice DS8A50
ID               IBM.2107-78SV001
Storage Unit     IBM.2107-78SV000
Model            A05
WWNN             5005076303FFF0DD
Signature        5a7e-0d5a-8a50-0001
State            Online
ESSNet           Enabled
Volume Group     -
os400Serial      001
NVS Memory       64.0 GB
Cache Memory     832.0 GB
Processor Memory 1015.6 GB
MTS              IBM.5341-78SV000

Decode it like this: MTS IBM.5341 is the G10 machine type and model A05 is the DS8A50 base frame. The ID ends in 1 (the storage image) and the Storage Unit ends in 0, the same rule licence keys follow, and an NVS of 64 GB matches the 1 TB memory option.

✅ Checkpoint: you can say “this is a DS8A50, model A05, machine type 5341” without looking at the desc line.

3Confirm with the processor nodes

Run this:

dscli> lspnode

You should see this:

Date/Time: 24 October 2026 19:50:21 UTC IBM DSCLI Version: 7.10.10.348 DS: IBM.2107-78SV001
ID State  Release Processor       Memory   Location
==============================================================
00 Online R10.1   Power9+ 20-core 512.0 GB U9009.42A.78SV00-P1
01 Online R10.1   Power9+ 20-core 512.0 GB U9009.42A.78SV01-P1

Twenty cores per CPC matches the DS8A50 row of the table, whereas a DS8A10 would show 10 cores and a DS8A80 24. Two nodes of 512 GB make up the 1 TB system, which is the smallest DS8A50 memory option.

✅ Checkpoint: 20-core per node, two nodes, 1 TB total.

4Count what is installed against the maximum

Run this:

dscli> lsioenclosure
dscli> lsstgencl IBM.2107-78SV001
dscli> lsarraysite

You should see this:

Date/Time: 24 October 2026 19:50:21 UTC IBM DSCLI Version: 7.10.10.348 DS: IBM.2107-78SV001
ID                 Frame State  Host adapters Device adapters Location code   S/N
========================================================================================
IBM.1400-1B1-78SV0 1     Online 1             2               U1400.1B1.78SV0 YE10SV0001
IBM.1400-1B2-78SV0 1     Online 1             2               U1400.1B2.78SV0 YE10SV0002
IBM.1400-1B3-78SV0 1     Online 2             0               U1400.1B3.78SV0 YE10SV0003
IBM.1400-1B4-78SV0 1     Online 0             0               U1400.1B4.78SV0 YE10SV0004
Date/Time: 24 October 2026 19:50:21 UTC IBM DSCLI Version: 7.10.10.348 DS: IBM.2107-78SV001
ID                    Frame Enclnum Loc   FC Interfaces State  DA pair
======================================================================
IBM.2107-D04-8SV01/R1 1     1       R1-D1 HPFE Gen3     Normal 0
IBM.2107-D04-8SV01/R2 1     2       R1-D2 HPFE Gen3     Normal 0
IBM.2107-D04-8SV02/R1 1     3       R1-D3 HPFE Gen3     Normal 2
IBM.2107-D04-8SV02/R2 1     4       R1-D4 HPFE Gen3     Normal 2
Date/Time: 24 October 2026 19:50:21 UTC IBM DSCLI Version: 7.10.10.348 DS: IBM.2107-78SV001
arsite DA Pair dkcap (10^9B) State      Array
=============================================
S1     0       4800.0        Unassigned -
S2     0       4800.0        Unassigned -
S3     0       4800.0        Unassigned -
S4     0       4800.0        Unassigned -
S5     2       4800.0        Unassigned -
S6     2       4800.0        Unassigned -
S7     2       3840.0        Unassigned -
S8     2       3840.0        Unassigned -

Work it out on paper. There are four I/O enclosures (two pairs) out of a possible eight, and two HPFE Gen3 pairs (four enclosures) out of a possible eight pairs.

Eight array sites of 8 drives gives 64 drives out of 384. For raw capacity, 6 sites x 8 x 4.8 TB = 230.4 TB plus 2 x 8 x 3.84 TB = 61.44 TB, which makes 291.84 TB of the 7,372.8 TB maximum.

✅ Checkpoint: 64 drives, 291.84 TB raw, and lots of room to grow inside this DS8A50.

5Give scripts a safe login

The sizing tool can read the box through the DS CLI, and for that it needs a password file and a script profile. Save the profile as auto.profile in your lab folder.

On macOS or Linux write the full path to your home folder, for example /home/you/dscli/security.dat.

Run this:

dscli> managepwfile -action add -name admin -pw <your password>
dscli> quit
notepad auto.profile

Put these 8 lines in auto.profile:

hmc1: 10.0.0.1
username: admin
pwfile: C:\Users\you\dscli\security.dat
devid: IBM.2107-78SV001
banner: off
header: on
format: delim
delim: ,

You should see this (after managepwfile):

CMUC00206I managepwfile: Record 10.0.0.1/admin successfully added to password file C:\Users\you\dscli\security.dat.

✅ Checkpoint: python ds8sim.py -cfg auto.profile showsi prints one comma-separated header line and one data line.

6Size a new project with model_fit.py

Save this script in the lab folder next to ds8sim.py. It runs on your laptop, not on the DS8000, and the model limits come straight from the DS8A00 Redbook tables you saw above.

# Planning tool: runs on your laptop, not on the DS8000.
# The model table below comes from IBM Redbook SG24-8559-01 (Tables 2-3 to 2-6, 2-15).
# Optional --check talks to the DS8000 only through the DS CLI (auto.profile: banner off, header on, format delim).
import argparse, csv, subprocess

DSCLI = ["python", "ds8sim.py", "-cfg", "auto.profile"]   # at work: ["dscli", "-cfg", "auto.profile"]

def dscli(*args):
    """Run one DS CLI command and return its rows as dictionaries."""
    out = subprocess.run(DSCLI + list(args), capture_output=True, text=True).stdout
    lines = [l for l in out.splitlines() if l and not l.startswith("SaatVedha") and not l.startswith("CMUC")]
    return list(csv.DictReader(lines))

# model: (MT-model, max memory GB, max host ports, max drives, max raw TB, max zHyperLink, frames)
MODELS = {
    "DS8A10": ("5341-A01/A00", 512, 64, 192, 3686.4, 4, 1),
    "DS8A50": ("5341-A05", 3584, 128, 384, 7372.8, 10, 2),
    "DS8A80": ("5341-A08", 4864, 128, 384, 7372.8, 12, 2),
}
CODE = {"A00": "DS8A10", "A01": "DS8A10", "A05": "DS8A50", "A08": "DS8A80"}

p = argparse.ArgumentParser()
p.add_argument("--raw-tb", type=float, default=0, help="raw TB you need today")
p.add_argument("--growth", type=float, default=0, help="growth per year in percent")
p.add_argument("--years", type=int, default=3)
p.add_argument("--ports", type=int, default=0)
p.add_argument("--memory-gb", type=int, default=0)
p.add_argument("--zhl", type=int, default=0)
p.add_argument("--check", action="store_true", help="compare with the installed box")
a = p.parse_args()

need_tb = a.raw_tb * (1 + a.growth / 100) ** a.years
print(f"Need in {a.years} years: {need_tb:.0f} TB raw, {a.ports} ports, {a.memory_gb} GB memory, {a.zhl} zHyperLink")
for name, (mtm, mem, ports, drives, raw, zhl, frames) in MODELS.items():
    gaps = []
    if need_tb > raw: gaps.append(f"raw {need_tb:.0f} > {raw} TB")
    if a.ports > ports: gaps.append(f"ports {a.ports} > {ports}")
    if a.memory_gb > mem: gaps.append(f"memory {a.memory_gb} > {mem} GB")
    if a.zhl > zhl: gaps.append(f"zHyperLink {a.zhl} > {zhl}")
    tight = need_tb > 0.8 * raw or a.ports > 0.8 * ports
    verdict = "NO   " if gaps else ("TIGHT" if tight else "FITS ")
    print(f"  {verdict} {name} ({mtm}, {frames} frame max) {'; '.join(gaps)}".rstrip())

if a.check:
    si = dscli("showsi")[0]
    model = CODE.get(si["Model"], "unknown")
    mem_gb = sum(float(n["Memory"].split()[0]) for n in dscli("lspnode"))
    ports = sum(int(h["Fibre Channel ports"]) for h in dscli("lshacard"))
    drives = len(dscli("lsdrive"))
    _, mmax, pmax, dmax, *_ = MODELS[model]
    print(f"Installed: {si['Name']} model {si['Model']} = {model} ({si['MTS']})")
    print(f"  memory {mem_gb:.0f} of {mmax} GB, host ports {ports} of {pmax} ({100*ports/pmax:.0f}%), "
          f"drives {drives} of {dmax} ({100*drives/dmax:.0f}%)")

Now size a university’s research storage three ways: on raw TB only, then with 35% growth a year for three years, and finally with ports and memory added.

Run this:

python model_fit.py --raw-tb 1200
python model_fit.py --raw-tb 1200 --growth 35 --years 3
python model_fit.py --raw-tb 1200 --growth 35 --years 3 --ports 40 --memory-gb 1024 --check

You should see this:

Need in 3 years: 1200 TB raw, 0 ports, 0 GB memory, 0 zHyperLink
  FITS  DS8A10 (5341-A01/A00, 1 frame max)
  FITS  DS8A50 (5341-A05, 2 frame max)
  FITS  DS8A80 (5341-A08, 2 frame max)
Need in 3 years: 2952 TB raw, 0 ports, 0 GB memory, 0 zHyperLink
  TIGHT DS8A10 (5341-A01/A00, 1 frame max)
  FITS  DS8A50 (5341-A05, 2 frame max)
  FITS  DS8A80 (5341-A08, 2 frame max)
Need in 3 years: 2952 TB raw, 40 ports, 1024 GB memory, 0 zHyperLink
  NO    DS8A10 (5341-A01/A00, 1 frame max) memory 1024 > 512 GB
  FITS  DS8A50 (5341-A05, 2 frame max)
  FITS  DS8A80 (5341-A08, 2 frame max)
Installed: ds8k-g10-lab model A05 = DS8A50 (IBM.5341-78SV000)
  memory 1024 of 3584 GB, host ports 16 of 128 (12%), drives 64 of 384 (17%)

See how the answer changes. On raw TB alone every model “fits”, but once you add growth the DS8A10 gets tight, above 80% of its 3,686.4 TB limit, and when you add a 1 TB cache need it drops out altogether. The --check part then reads the installed box through the DS CLI and shows how much headroom it has left, and at work you’d point the same script at the dscli command on a jump server.

✅ Checkpoint: the third run prints NO for DS8A10 and the Installed line shows 16 of 128 ports and 64 of 384 drives.