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--- zfs:filesystems:set_properties_for_a_filesystem [2021/10/13 13:26] – peter
+++ zfs:filesystems:set_properties_for_a_filesystem [2021/10/13 22:09] (current) – [Deduplication] peter
@@ Line 5: / Line 5: @@
 ----
-==== Compression ====
+===== Compression =====
 <code bash>
@@ Line 11: / Line 11: @@
 </code>
-----
+<WRAP info>
+**NOTE:**  The default Compression is lz4.
-==== Deduplication ====
+  * lz4 is significantly faster than the other options while still performing well;
+  * lz4 is also the safest choice.
-ZFS dedup will discard blocks that are identical to existing blocks and will instead use a reference to the existing block.
+The compression level can be changed if required:
-  * This saves space on the device but comes at a large cost to memory.
+<code bash>
-  * The dedup in-memory table uses ~320 bytes per block.
+sudo zfs set compression=gzip-9 testpool
-  * The greater the table is in size, the slower write performance becomes.
+</code>
+The compression type can be changed too:
 <code bash>
-sudo zfs set dedup=on testpool/projects
+sudo zfs set compression=lz4 testpool
 </code>
-<WRAP info>
+The compression level can be checked:
-**NOTE:**  There are pros and cons to deduping.
-  * Generally, Deduplication is almost never worth the performance penalty.
+<code bash>
+sudo zfs get compressratio
+</code>
 </WRAP>
@@ Line 34: / Line 39: @@
 ----
-==== Ditto Blocks ====
+===== Copies / Ditto Blocks =====
 Ditto blocks create more redundant copies of data to copy, just for more added redundancy.
@@ Line 51: / Line 56: @@
 </WRAP>
+----
+===== Deduplication =====
+ZFS dedup will discard blocks that are identical to existing blocks and will instead use a reference to the existing block.
+  * This saves space on the device but comes at a large cost to memory.
+  * The dedup in-memory table uses ~320 bytes per block.
+  * The greater the table is in size, the slower write performance becomes.
+<code bash>
+sudo zfs set dedup=on testpool/projects
+</code>
+<WRAP info>
+**NOTE:**  There are pros and cons to deduping.
+  * Generally, De-duplication is almost never worth the performance penalty.
+</WRAP>
 ----
-==== Quota ====
+===== Mount Point =====
+<code bash>
+zfs set mountpoint=/test testpool/projects
+df -h |grep /test
+</code>
+----
+===== Quota =====
 <code bash>
@@ Line 62: / Line 96: @@
 <WRAP info>
 **NOTE:**  This sets a maximum quota of 10 gigabytes.
-</WRAP>
+  * The Filesystem cannott use more than this amount.
+</WRAP>
 ----
+===== Reservations =====
+<code bash>
+sudo zfs set reservation=200m testpool/tmp
+</code>
+<WRAP info>
+**NOTE:**  This much space is reserved for the Filesystem.
+  * It will not be available to other Filesystems.
+  * When a Quota is defined first, a reservation cannot be higher than quota.
+</WRAP>