From 64f640ba94a15ac92135ce31595814424c62edfa Mon Sep 17 00:00:00 2001
From: kneutron <50146127+kneutron@users.noreply.github.com>
Date: Sun, 11 Jul 2021 14:37:22 -0500
Subject: [PATCH] Add files via upload

---
 ZFS/zfs-drive-slicer.sh | 62 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 ZFS/zfs-drive-slicer.sh

diff --git a/ZFS/zfs-drive-slicer.sh b/ZFS/zfs-drive-slicer.sh
new file mode 100644
index 0000000..84040a4
--- /dev/null
+++ b/ZFS/zfs-drive-slicer.sh
@@ -0,0 +1,62 @@
+#!/bin/bash
+
+# 2021 Dave Bechtel
+# Get me a set of disks for DRAID 
+# DONE [b..y] a[a..x] get slices of X disks and be able to verify with wc -w
+
+# REF: https://tldp.org/LDP/abs/html/arrays.html
+# regular array - STARTS AT 0
+declare -a fullset=(sd{b..y} sda{a..x} sdb{a..x} sdc{a..x}) # Total 96, excluding spares
+# sdz, sday sdaz, sdby sdbz, sdcy sdcz == Reserved for spares (7)
+
+# integer
+declare -i howmany sliceby idx x
+
+function slice () {
+ howmany=$1
+ sliceby=$2
+ idx=0
+ for x in $(seq 0 1 $howmany); do
+   [ $x -ge $howmany ] && break
+
+   let idx=$idx+1
+
+#   echo -n "${fullset[$idx]} "
+   printf "${fullset[$x]} " # no newline
+
+   if [ $idx -ge $sliceby ]; then
+     echo ' \'
+     idx=0
+   fi
+ done
+echo ''
+}
+
+if [ "$1"  = "" ];  then
+# Demo
+# copypasta not-including the '\' and verify with:  echo '[paste]' |wc -w
+  slice 72 72
+  echo '===== ^^ 72 / 72'
+
+  slice 72 36
+  echo '===== ^^ 72 / 36'
+
+  slice 72 24
+  echo '===== ^^ 72 / 24'
+# = sd{b..y} sda{a..l} \
+#sda{m..x} sdb{a..x}
+exit; # early
+fi
+
+# Basic sanity
+if [ "$1" -lt "$2" ]; then
+  echo "$0 - Failed sanity check, \$2 must be greater than \$1"
+  exit 999; # Somebody call Scotland Yard, we have a violation
+fi
+
+slice $1 $2
+
+# This is a decent method because we can give it arbitrary numbers of disks (up to total defined) 
+#   and divide as needed; try 26 2, 24 2, 32 4, 32 8
+# NOTE all output lines should have the same length - if you dont you wont have a balanced set of disks
+# e.g. 32 6 = invalid config (32 4 = valid) but we just give you output - sanity checks are up 2U