此文為計算機系統與網路管理課程 lab4 的實作
gdisk
首先助教分配了 /dev/vdb 和 /dev/vdc 這兩顆磁碟，各自都有 8 GiB 的容量。首先要將它們各自切成 4 GiB 的分割，總共會產生 4 個磁區。
因為我是先做完一次了，所以 gdisk 進入時會偵測到 GPT table 已經存在。如果是完全空的磁碟， gdisk 會在記憶體中先創建一個 GPT table ，在分割完存檔之後會自動把 GPT table 寫到硬碟中。記得設定完成一定要輸入 w 儲存。
$ sudo gdisk /dev/vdc
GPT fdisk (gdisk) version 1.0.5
Partition table scan:
MBR: not present
BSD: not present
APM: not present
GPT: present
Found valid GPT with corrupt MBR; using GPT and will write new
protective MBR on save.
Command (? for help): p
Disk vdc: 16777216 sectors, 8.0 GiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): 2D642148-4BF0-4563-BB9A-9272A52AB41E
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 16777182
Partitions will be aligned on 2048-sector boundaries
Total free space is 16777149 sectors (8.0 GiB)
Number Start (sector) End (sector) Size Code Name
Command (? for help): n
Partition number (1-128, default 1):
First sector (34-16777182, default = 2048) or {+-}size{KMGTP}:
Last sector (2048-16777182, default = 16777182) or {+-}size{KMGTP}: +4096M
Current type is 8300 (Linux filesystem)
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'
Command (? for help): n
Partition number (2-128, default 2):
First sector (34-16777182, default = 8390656) or {+-}size{KMGTP}:
Last sector (8390656-16777182, default = 16777182) or {+-}size{KMGTP}:
Current type is 8300 (Linux filesystem)
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'
Command (? for help): p
Disk vdc: 16777216 sectors, 8.0 GiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): 2D642148-4BF0-4563-BB9A-9272A52AB41E
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 16777182
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number Start (sector) End (sector) Size Code Name
1 2048 8390655 4.0 GiB 8300 Linux filesystem
2 8390656 16777182 4.0 GiB 8300 Linux filesystem
Command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): Y
OK; writing new GUID partition table (GPT) to vdc.
The operation has completed successfully.
這樣便分割好 \dev\vdc ，對於 \dev\vdb 也是相同的操作
mdadm 建立 RAID1 陣列
我第一次做時沒看清楚題目，把 vdb1 和 vdb2 做成 RAID0 ，指令如下:
sudo mdadm -Cv -l 0 /dev/md0 -n 2 /dev/vdb1 /dev/vdb2
正確來說 -l 後面要打 1 才是 RAID1，所以我又輸入以下指令還原:
$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid0 vdb2[1] vdb1[0]
8376832 blocks super 1.2 512k chunks
unused devices: <none>
$ sudo mdadm --stop /dev/md0
mdadm: stopped /dev/md0
$ sudo mdadm --zero-superblock /dev/vdb1 /dev/vdb2
$ sudo cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
unused devices: <none>
現在用 vdb1 和 vdc1 重新造一個 RAID1
$ sudo mdadm -Cv -l 1 /dev/md0 -n 2 /dev/vdb1 /dev/vdc1
mdadm: /dev/vdb1 appears to contain an ext2fs file system
size=4194304K mtime=Thu Jan 1 00:00:00 1970
mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
mdadm: /dev/vdc1 appears to contain an ext2fs file system
size=4194304K mtime=Thu Jan 1 00:00:00 1970
mdadm: size set to 4189184K
Continue creating array?
會遇到上面這樣的提示，直接按 Y 就好。
之後需要等 mdadm 重新同步:
$ sudo cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 vdc1[1] vdb1[0]
4189184 blocks super 1.2 [2/2] [UU]
[=>...................] resync = 7.0% (295872/4189184) finish=12.7min speed=5069K/sec
unused devices: <none>
同步完成後，將其格式化成 ext4
$ sudo mkfs.ext4 /dev/md0
mke2fs 1.45.5 (07-Jan-2020)
Discarding device blocks: done
Creating filesystem with 1047296 4k blocks and 262144 inodes
Filesystem UUID: 2a43811b-197a-4139-893f-825dabd463d7
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
mount 到 /mnt/raid1
$ sudo mkdir /mnt/raid1
$ sudo mount /dev/md0 /mnt/raid1
ZFS
$ sudo zpool create ncku-nasa /dev/vdb2 /dev/vdc2
$ zpool status
pool: ncku-nasa
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
ncku-nasa ONLINE 0 0 0
vdb2 ONLINE 0 0 0
vdc2 ONLINE 0 0 0
errors: No known data errors
$ zfs get all ncku-nasa | grep compress
ncku-nasa compressratio 1.00x -
ncku-nasa compression off default
ncku-nasa refcompressratio 1.00x -
$ sudo zfs set compression=lz4 ncku-nasa
$ zfs get all ncku-nasa | grep compress
ncku-nasa compressratio 1.00x -
ncku-nasa compression lz4 local
ncku-nasa refcompressratio 1.00x -
