From 9a0b5d68f6edc7be7804b34c05f20116f059d8ce Mon Sep 17 00:00:00 2001
From: kneutron <50146127+kneutron@users.noreply.github.com>
Date: Sat, 16 Apr 2022 18:04:54 -0500
Subject: [PATCH] Add files via upload

---
 ZFS/zfs-on-optical-disc.sh | 90 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 ZFS/zfs-on-optical-disc.sh

diff --git a/ZFS/zfs-on-optical-disc.sh b/ZFS/zfs-on-optical-disc.sh
new file mode 100644
index 0000000..d5a0de4
--- /dev/null
+++ b/ZFS/zfs-on-optical-disc.sh
@@ -0,0 +1,90 @@
+#!/bin/bash5
+
+# osx, should adapt easily to linux
+# REF: http://girlyngeek.blogspot.com/2014/02/zfs-on-read-only-devices.html
+# Having trouble importing zpool on osx from "raw" write w/no containing filesystem, 
+#   decided to switch to UDF filesystem for optical - mount that and import zfs file-based pool
+
+# failexit.mrg
+function failexit () {
+  echo '! Something failed! Code: '"$1 $2" # code # (and optional description)
+  exit $1
+}
+
+userowns=dave # xxx TODO EDITME
+
+# xxx EDITME
+zpfile=zopticalpool
+fsize=4400 # MB - for standard DVD+/-R
+howmany=1 # for 4.7G DVD+RW
+
+function mkpool () {
+  echo "o $PWD - Creating optical zpool of $howmany""x$fsize"" MB"
+  for z in $(seq 1 $howmany); do
+    time gdd if=/dev/zero of="$zpfile"_$z bs=1M conv=sparse count=$fsize \
+    || failexit 99 "Failed to DD output zpool file $z"
+  done
+}
+
+# Only if not exist
+[ -e "$zpfile"_1 ] || mkpool
+
+chown -v $userowns $zpfile*
+
+# xxx EDITME
+zp=myzfsdvd
+devs=$(echo $PWD/zopticalpool_*)
+# -O mountpoint=$HOME/myzfsdvd -O checksum=sha256 \
+# NOTE RAID0
+zpool create -o ashift=11 -o failmode=continue -o autoexpand=off -o autoreplace=off \
+ -O checksum=sha256 -O compression=gzip-9 -O dedup=on \
+ -O atime=off -O devices=off -O exec=off -O setuid=off \
+ $zp $devs \
+ || failexit 101 "Failed to create zpool $zp"
+
+mp=$(zfs get mountpoint $zp |tail -n 1 |awk '{print $3}')
+#NAME      PROPERTY    VALUE              SOURCE
+#myzfsdvd  mountpoint  /Volumes/myzfsdvd  default
+#/Volumes/myzfsdvd
+
+# osx
+[ $(df |grep -c Volumes/$zp) -gt 0 ] && chown -v $userowns /Volumes/$zp
+# Linux
+[ -e /$zp ] && chown -v $userowns /$zp
+
+zpool status -v $zp |awk 'NF>0'
+ls -al $mp
+echo ''
+gdf -hT |head -n 1
+gdf -hT |grep $zp
+
+echo '====='
+echo "To burn to disc, FIRST zpool export $zp"
+echo "To re-import $zp -- mount dvd, cd to it, then zpool import -o readonly=on $zp -d \$PWD"
+
+echo "/Volumes/zfsoptical # zpool import -a -o readonly=on -d \$PWD" > howto-reimport-zpool.txt
+cp -v $0 $PWD
+
+exit;
+
+
+# OSX disc burning REF: https://support.apple.com/guide/mac-help/burn-cds-and-dvds-mchl8addfd95/12.0/mac/12.0
+# to burn dvd on osx from files, better to use "burn" app as it can also Erase RW discs
+
+# For larger media, e.g. 50GB Bluray, might want to do copies=2 and forgo raidz1 as seeking will slow down I/O
+
+declare -A ASsector # assoc array
+
+ASsector[74min]=333000          # for 74-min CD-Rs and CD-RWs / 650MB
+ASsector[80min]=360000          # for 80-min CD-Rs and CD-RWs / 700MB
+ASsector[dvd]=2298496           # for single-layer DVD-Rs
+ASsector[dvddouble]=4171712     # for double-layer DVD-Rs
+ASsector[dvdplusr]=2295104      # for single-layer DVD+Rs
+ASsector[dvdplusr2]=4173824     # for double-layer DVD+Rs
+ASsector[bluray]=12219392       # for single-layer Blu-rays
+ASsector[bluray2]=24438784      # for double-layer Blu-rays
+ASsector[bluray3]=48878592      # for triple-layer Blu-rays
+ASsector[bluray4]=62500864      # for quad-layer Blu-rays
+
+usesector=${ASsector[dvdplusr]} 
+#echo $usesector