Add HW4-zfs/POOLSETTINGS.md. Some small fixes

HW4-zfs/POOLSETTINGS.md

@@ -0,0 +1,167 @@
+# Determine pool settings
+
+All actions executed on clean VM
+
+## Prepare
+
+Install zfs (run on host)
+```shell
+cat install.sh | vagrant ssh -c "bash"
+```
+
+## Get disk image with zfs
+
+Fetch and extract disk image (download link is modified to download image with `wget` command)
+```shell
+cd ~
+wget -O zfsdisk.img.tar.gz "https://drive.google.com/u/0/uc?id=1KRBNW33QWqbvbVHa3hLJivOAt60yukkg&export=download"
+tar xvzf zfsdisk.img.tar.gz
+```
+```log
+zpoolexport/
+zpoolexport/filea
+zpoolexport/fileb
+```
+
+A content of the archive
+```shell
+cd ~/zpoolexport
+ls -l
+```
+```log
+total 1024000
+-rw-r--r-- 1 vagrant vagrant 524288000 May 15 05:00 filea
+-rw-r--r-- 1 vagrant vagrant 524288000 May 15 05:00 fileb
+```
+
+List available pools
+```shell
+sudo zpool import -d ~/zpoolexport
+```
+```log
+   pool: otus
+     id: 6554193320433390805
+  state: ONLINE
+ action: The pool can be imported using its name or numeric identifier.
+ config:
+
+        otus                                 ONLINE
+          mirror-0                           ONLINE
+            /home/vagrant/zpoolexport/filea  ONLINE
+            /home/vagrant/zpoolexport/fileb  ONLINE
+```
+
+## Mount zfs
+
+Import pool
+```shell
+sudo zpool import -d ~/zpoolexport otus
+sudo zpool list
+```
+```log
+NAME   SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
+otus   480M  2.18M   478M        -         -     0%     0%  1.00x    ONLINE  -
+```
+
+Check content
+```shell
+tree /otus
+```
+<details><summary>output</summary>
+<p>
+
+```log
+/otus/
+└── hometask2
+    ├── dir1
+    │   ├── dir101
+    │   ├── dir1010
+    │   ├── dir102
+    │   ├── dir103
+    │   ├── dir104
+    │   ├── dir105
+    │   ├── dir106
+...
+        ├── dir92
+        ├── dir93
+        ├── dir94
+        ├── dir95
+        ├── dir96
+        ├── dir97
+        ├── dir98
+        └── dir99
+
+17537 directories, 0 files
+```
+</p>
+</details>
+
+## Analize
+
+Pool size (`480M`)
+```shell
+zpool get size otus
+NAME  PROPERTY  VALUE  SOURCE
+otus  size      480M   -
+```
+
+ZFS Size (`350M`)
+```shell
+sudo zfs list
+```
+```log
+NAME             USED  AVAIL     REFER  MOUNTPOINT
+otus            1.99M   350M       24K  /otus
+otus/hometask2  1.80M   350M     1.80M  /otus/hometask2
+```
+
+Pool type (`mirror`)
+```shell
+zpool status
+```
+```log
+  pool: otus
+ state: ONLINE
+  scan: none requested
+config:
+
+        NAME                                 STATE     READ WRITE CKSUM
+        otus                                 ONLINE       0     0     0
+          mirror-0                           ONLINE       0     0     0
+            /home/vagrant/zpoolexport/filea  ONLINE       0     0     0
+            /home/vagrant/zpoolexport/fileb  ONLINE       0     0     0
+
+errors: No known data errors
+```
+
+Recordsize (`128K`)
+```shell
+zfs get recordsize
+```
+```log
+NAME            PROPERTY    VALUE    SOURCE
+otus            recordsize  128K     local
+otus/hometask2  recordsize  128K     inherited from otus
+```
+
+Compression type (`zle`)
+```shell
+zfs get compression
+```
+```log
+NAME            PROPERTY     VALUE     SOURCE
+otus            compression  zle       local
+otus/hometask2  compression  zle       inherited from otus
+```
+
+Checksum algorithm (`sha256`)
+```shell
+zfs get checksum
+```
+```log
+NAME            PROPERTY  VALUE      SOURCE
+otus            checksum  sha256     local
+otus/hometask2  checksum  sha256     inherited from otus
+```
+
+**Settings description** is available in `man 8 zfs` and `man 8 zpool`

HW4-zfs/README.md

@@ -3,3 +3,7 @@
 ## The best compression algorithm
 
 [COMPRESSION.md](./COMPRESSION.md)
+
+## Determine pool settings
+
+[POOLSETTINGS.md][./POOLSETTINGS.md]

HW4-zfs/create.sh

@@ -2,9 +2,6 @@
 
 set -ex
 
-echo Ensure module is mounted
-sudo /sbin/modprobe zfs
-
 echo Create zfs pool named zpool with cache
 sudo zpool create zpool sdb cache sdc
 sudo zpool status

HW4-zfs/install.sh

@@ -10,3 +10,6 @@ sudo gpg --quiet --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-zfsonlinux
 
 echo "Install (it can take a long time on weak machine)"
 sudo yum install -y zfs
+
+echo "Ensure zfs kernel module is mounted"
+sudo /sbin/modprobe zfs

HW4-zfs/pool.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+echo Fetch and extract disk image
+cd ~
+test -f zfsdisk.img.tar.gz || wget -O zfsdisk.img.tar.gz https://drive.google.com/u/0/uc?id=1KRBNW33QWqbvbVHa3hLJivOAt60yukkg&export=download
+ls -lah zfsdisk.img.tar.gz
+tar xvzf zfsdisk.img.tar.gz
+
+echo "Import zpool from files"
+sudo zpool import -d ~/zpoolexport otus
+sudo zpool list
+