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--- quickreference:zfs [2022/12/17 13:59] – rodolico
+++ quickreference:zfs [2024/02/03 23:04] (current) – rodolico
@@ Line 56: / Line 56: @@
 # turn swap back on (could also use swapon /dev/zvol/storage/swap, but I'm lazy)
 swapon -aL
+</code>
+===== Using a file for swap space =====
+Instead of using a swap partition or zvol, we can simply use a file. In this case, we can add swap space by deleting/recreating the swap file (after turning swap off), but a simpler way if you need more swap space is to simply add a second swap file.
+Following code creates an 8G swap file. Note that after reading https://www.cyberciti.biz/faq/create-a-freebsd-swap-file/, I modified my old way of doing this.
+<code bash>
+# create an 8G swap file
+dd if=/dev/zero of=/swap bs=1G count=8
+# set permissions
+chmod 0600 /swap
+# look for an unused md device (ie, not listed)
+mdconfig -lv
+cp /etc/fstab /etc/fstab.save
+# edit /etc/fstab and add the following line, using the correct md##
+joe /etc/fstab
+md42	none	swap	sw,file=/swap	0	0
+# save your file
+# turn on swap
+swapon -aq
+# look at swap information
+swapinfo -k
 </code>
 ===== iSCSI considerations =====
+On FreeBSD, the iSCSI config is /etc/ctl.conf, and the service is ctld <code bash>service ctld reload # reread iscsi exports on FreeBSD</code>
 iSCSI generally uses volumes which are then exported by the target. I have found that it is useful, from a management perspective, to place them under a dataset strictly for them, since I back up iSCSI volumes on a different timeline than I do other stuff.
@@ Line 86: / Line 112: @@
   - On iSCSI target
     - Rename the volume <code bash> zfs rename storage/volumename storage/iscsi/volumename</code>
-    - Edit the config to point to new location
+    - Edit the config to point to new location (**/etc/ctl.conf** on FreeBSD)
-    - reload iscsi service
+    - reload iscsi service <code bash>service ctld reload # on FreeBSD</code>
   - On initiator
     - rescan target
     - allow access to volume
-I have **NOT** done this yet. This is based on some research I have done, and a little testing, so use at your own risk.
 ===== Getting and setting properties =====
@@ Line 156: / Line 182: @@
    * https://wordpress.morningside.edu/meyersh/2009/11/30/zfs-deduplication/
    * https://linuxhint.com/zfs-deduplication/
+   * https://www.cyberciti.biz/faq/create-a-freebsd-swap-file/