diff --git a/TuringPi/zfs.md b/TuringPi/zfs.md
index 4590e5b..efd372d 100644
--- a/TuringPi/zfs.md
+++ b/TuringPi/zfs.md
@@ -149,3 +149,107 @@ sudo systemctl enable zfs-import-cache
PS : on Debian, the installation of zfs-zed may already set up the necessary services.
You can configure /etc/zfs/zfs-list.cache (automatically generated) for faster mounting.
+
+---
+
+### Querying ZFS File System Information
+
+The zfs list command provides an extensible mechanism for viewing and querying dataset information. Both basic and complex queries are explained in this section.
+
+#### Listing Basic ZFS Information
+
+You can list basic dataset information by using the zfs list command with no options. This command displays the names of all datasets on the system and the values of their used, available, referenced, and mountpoint properties. For more information about these properties, see [Introducing ZFS Properties](https://docs.oracle.com/cd/E18752_01/html/819-5461/gazsu.htmlgazss.html).
+
+For example:
+
+```
+# zfs list
+NAME USED AVAIL REFER MOUNTPOINT
+pool 476K 16.5G 21K /pool
+pool/clone 18K 16.5G 18K /pool/clone
+pool/home 296K 16.5G 19K /pool/home
+pool/home/marks 277K 16.5G 277K /pool/home/marks
+pool/home/marks@snap 0 - 277K -
+pool/test 18K 16.5G 18K /test
+```
+
+You can also use this command to display specific datasets by providing the dataset name on the command line. Additionally, use the \-r option to recursively display all descendents of that dataset. For example:
+
+```
+# zfs list -r pool/home/marks
+NAME USED AVAIL REFER MOUNTPOINT
+pool/home/marks 277K 16.5G 277K /pool/home/marks
+pool/home/marks@snap 0 - 277K -
+```
+
+You can use the zfs list command with the mount point of a file system. For example:
+
+```
+# zfs list /pool/home/marks
+NAME USED AVAIL REFER MOUNTPOINT
+pool/home/marks 277K 16.5G 277K /pool/home/marks
+```
+
+The following example shows how to display basic information about tank/home/chua and all of its descendent datasets:
+
+```
+# zfs list -r tank/home/chua
+NAME USED AVAIL REFER MOUNTPOINT
+tank/home/chua 26.0K 4.81G 10.0K /tank/home/chua
+tank/home/chua/projects 16K 4.81G 9.0K /tank/home/chua/projects
+tank/home/chua/projects/fs1 8K 4.81G 8K /tank/home/chua/projects/fs1
+tank/home/chua/projects/fs2 8K 4.81G 8K /tank/home/chua/projects/fs2
+```
+
+For additional information about the zfs list command, see [zfs(1M)](https://docs.oracle.com/cd/E18752_01/html/819-5461/gazsu.html../816-5166/zfs-1m.html#REFMAN1Mzfs-1m).
+
+#### Creating Complex ZFS Queries
+
+The zfs list output can be customized by using the \-o, \-t, and \-H options.
+
+You can customize property value output by using the \-o option and a comma-separated list of desired properties. You can supply any dataset property as a valid argument. For a list of all supported dataset properties, see [Introducing ZFS Properties](https://docs.oracle.com/cd/E18752_01/html/819-5461/gazsu.htmlgazss.html). In addition to the properties defined, the \-o option list can also contain the literal name to indicate that the output should include the name of the dataset.
+
+The following example uses zfs list to display the dataset name, along with the sharenfs and mountpoint property values.
+
+```
+# zfs list -o name,sharenfs,mountpoint
+NAME SHARENFS MOUNTPOINT
+tank off /tank
+tank/home on /tank/home
+tank/home/ahrens on /tank/home/ahrens
+tank/home/bonwick on /tank/home/bonwick
+tank/home/chua on /tank/home/chua
+tank/home/eschrock on legacy
+tank/home/moore on /tank/home/moore
+tank/home/tabriz ro /tank/home/tabriz
+```
+
+You can use the \-t option to specify the types of datasets to display. The valid types are described in the following table.
+
+**Table 6-2 Types of ZFS Datasets**
+
+
Type
Description
filesystem
File systems and clones
volume
Volumes
snapshot
Snapshots
+
+The \-t options takes a comma-separated list of the types of datasets to be displayed. The following example uses the \-t and \-o options simultaneously to show the name and used property for all file systems:
+
+```
+# zfs list -t filesystem -o name,used
+NAME USED
+pool 476K
+pool/clone 18K
+pool/home 296K
+pool/home/marks 277K
+pool/test 18K
+```
+
+You can use the \-H option to omit the zfs list header from the generated output. With the \-H option, all white space is replaced by the Tab character. This option can be useful when you need parseable output, for example, when scripting. The following example shows the output generated from using the zfs list command with the \-H option:
+
+```
+# zfs list -H -o name
+pool
+pool/clone
+pool/home
+pool/home/marks
+pool/home/marks@snap
+pool/test
+```