refactor of original script

ZFS/zfs-drive-slicer-xargs-simplified.sh

@@ -0,0 +1,155 @@
+#!/bin/bash
+
+#set -x
+# PROTIP use bash5 from macports/brew on osx, much faster
+# Get me a set of shortname disks for DRAID 
+# DONE [b..y] a[a..x] get slices of X disks and be able to verify with wc -w
+# REQUIRES: xargs, cut
+
+# Trick to put header outside of col -t
+>&2 echo "$0 - 2022 Dave Bechtel" 
+>&2 echo "Pass arg1=total disks in pool -- arg2=how many disks per vdev" 
+>&2 echo "+ NOTE arg2 ^^ should factor in the RAIDz level 1/2/3 desired to sustain X number" 
+>&2 echo "+ of failed disks per vdev + vspares, dont go too narrow or will lose capacity" 
+>&2 echo "NOTE output lines NEED to be the same number of devices to balance"
+>&2 echo "DO NOT FORGET to prefix these lines with raidz2, mirror or whatever is applicable!"
+>&2 echo "PROTIP: Pipe output to  column -t  to make it look nice" 
+>&2 echo "=================================================================================="
+
+# REF: https://tldp.org/LDP/abs/html/arrays.html
+# regular array - STARTS AT 0
+# NOTE vv keep this commented, slows waaay down on bash 3.x osx
+#declare -a fullset=(sd{b..y} sda{a..x} sdb{a..x} sdc{a..x}) sdd{a..x}  # Total 120, sets of 24 
+# NOTE ^^ intentionally has gaps -- sdz, sday sdaz, sdby sdbz, sdcy sdcz, sddy sddz == Reserved for spares (9)
+
+
+function slice () {
+# (echo sd{b..y} sda{a..x} sdb{a..x} sdc{a..x} sdd{a..x}) |wc -w # to print sum-total number of drives
+
+# cut prints X range of fields (limit number of total drives), xargs breaks them up by 2nd arg
+  (echo sd{b..y} sda{a..x} sdb{a..x} sdc{a..x} sdd{a..x}) \
+  |cut -d' ' -f1-$1 \
+  |xargs -n $2 
+}
+
+if [ "$1"  = "" ];  then
+# Demo
+echo "o Copypasta each line and verify with:  echo '[paste]' |wc -w "
+  slice 72 72
+  echo '===== ^^ 72 / 72 -- One Big Mother vdev'
+  echo ''
+  slice 72 36
+  echo '===== ^^ 72 / 36 -- 2 VDEVs'
+  echo ''
+  slice 72 24
+  echo '===== ^^ 72 / 24 -- 3 VDEVs'
+  slice 96 12
+  echo '===== ^^ 96 / 12 -- 8 VDEVs'
+# = 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
+
+arg1=$1
+arg2=$2
+
+# REF: https://stackoverflow.com/questions/806906/how-do-i-test-if-a-variable-is-a-number-in-bash/806923
+re='^[0-9]+$'
+if ! [[ $arg1 =~ $re ]] ; then
+   echo "error: arg1 Not a number" >&2; exit 666
+fi
+if ! [[ $arg2 =~ $re ]] ; then
+   echo "error: arg1 Not a number" >&2; exit 666
+fi
+
+slice $arg1 $arg2 
+
+# DO NOT put exit in case we get SOURCEd for the function(?)
+
+# 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 -- real sanity checks are up 2U
+
+# HOW THIS WORKS: 
+# Imagine a set of disks sdb..sdcx , 96 in total, set along a slide rule
+# "xargs" is our slider/window
+# "cut" only prints up to the total number of drives we limit it to
+# If $2 >= however many drives we need per vdev, it drops down a line - 
+#   giving us the exact short drive names needed to create a zfs pool per-vdev
+
+
+# Example for 60-bay Storinator from 45drives - gives us 56 usable disks in pool + 3 spares (sdz sday sdaz), and 4 vdevs
+# $0  56 14 |column -t
+#sdb   sdc   sdd   sde   sdf   sdg   sdh   sdi   sdj   sdk   sdl   sdm   sdn   sdo   \
+#sdp   sdq   sdr   sds   sdt   sdu   sdv   sdw   sdx   sdy   sdaa  sdab  sdac  sdad  \
+#sdae  sdaf  sdag  sdah  sdai  sdaj  sdak  sdal  sdam  sdan  sdao  sdap  sdaq  sdar  \
+#sdas  sdat  sdau  sdav  sdaw  sdax  sdba  sdbb  sdbc  sdbd  sdbe  sdbf  sdbg  sdbh  \
+
+# Example for 45drives with 1 spare (sdz), 4 vdevs of 11:
+# $0  44 11 |column -t
+#sdb   sdc   sdd   sde   sdf   sdg   sdh   sdi   sdj   sdk   sdl   \
+#sdm   sdn   sdo   sdp   sdq   sdr   sds   sdt   sdu   sdv   sdw   \
+#sdx   sdy   sdaa  sdab  sdac  sdad  sdae  sdaf  sdag  sdah  sdai  \
+#sdaj  sdak  sdal  sdam  sdan  sdao  sdap  sdaq  sdar  sdas  sdat  \
+#
+# If you want more spares (5): (reserved sdz sdaq sdar sdas sdat) == 1 spare for every 8 drives
+# $0  40 10 |column -t
+#sdb   sdc   sdd   sde   sdf   sdg   sdh   sdi   sdj   sdk   \
+#sdl   sdm   sdn   sdo   sdp   sdq   sdr   sds   sdt   sdu   \
+#sdv   sdw   sdx   sdy   sdaa  sdab  sdac  sdad  sdae  sdaf  \
+#sdag  sdah  sdai  sdaj  sdak  sdal  sdam  sdan  sdao  sdap  \
+
+# (echo sd{b..y} sda{a..x} sdb{a..x} sdc{a..x} sdd{a..x}) |cut -d' ' -f1-15 |xargs -n 5
+#sdb sdc sdd sde sdf
+#sdg sdh sdi sdj sdk
+#sdl sdm sdn sdo sdp
+
+
+# HOWTO Verify output from this script
+# $0  42 14 |column -t >/tmp/zfsds.txt
+
+# sed -i 's/\\//g' /tmp/zfsds.txt   # remove line-continuation chars
+
+# cat /tmp/zfsds.txt 
+#sdb   sdc   sdd   sde   sdf   sdg   sdh   sdi   sdj   sdk   sdl   sdm   sdn   sdo   
+#sdp   sdq   sdr   sds   sdt   sdu   sdv   sdw   sdx   sdy   sdaa  sdab  sdac  sdad  
+#sdae  sdaf  sdag  sdah  sdai  sdaj  sdak  sdal  sdam  sdan  sdao  sdap  sdaq  sdar  
+
+# while read line; do echo "$line" |wc -w; done < /tmp/zfsds.txt 
+#      14
+#      14
+#      14
+
+#===========================
+# HOWTO get long-form disks:
+# $0  arg1 arg2  >/tmp/zfsds.txt
+# Then use  drive-slicer-get-longform.sh
+# ^ Requires output from this script
+
+# PROTIP to add in raidz2 prefix and trailing '\':
+# ./zfs-drive-slicer-xargs-simplified.sh 80 8 |while read line; do printf "%s" "raidz2 $line \\";echo ''; done
+
+# ./zfs-drive-slicer-xargs-simplified.sh 20 2 |while read line; do printf "%s" "mirror $line \\";echo ''; done
+#mirror sdb sdc \
+#mirror sdd sde \
+#...
+#mirror sdt sdu \
+
+# Triple mirroring
+# $ ./zfs-drive-slicer-xargs-simplified.sh 15 3 |while read line; do printf "%s" "mirror $line \\";echo ''; done
+#mirror sdb sdc sdd \
+#mirror sde sdf sdg \
+#...
+#mirror sdn sdo sdp \
+
+
+# 2022.0127 substantially refactored to use xargs and cut for simplicity
+# works with bash 3.2.57 osx