$ zpool status ztest
pool: ztest
state: ONLINE
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 0
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$ zpool list -v ztest
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
ztest 3.75G 3.62G 128M - - 72% 96% 1.00x ONLINE -
mirror-0 3.75G 3.62G 128M - - 72% 96.7% - ONLINE
gpt/tt1 - - - - - - - - ONLINE
gpt/tt2 - - - - - - - - ONLINE
$ zfs list ztest
NAME USED AVAIL REFER MOUNTPOINT
ztest 420K 3.62G 96K /ztest
$ df /ztest/
Filesystem 512-blocks Used Avail Capacity Mounted on
ztest 7601576 192 7601384 0% /ztest
写入虚拟数据
现在使用 dd 命令以零数据填充文件系统，就像上次的实验一样。
$ dd if=/dev/zero of=/ztest/dummy bs=1m
dd: /ztest/dummy: No space left on device
3711+0 records in
3710+1 records out
3891134464 bytes transferred in 151.249101 secs (25726662 bytes/sec)
$ df -h /ztest/
Filesystem Size Used Avail Capacity Mounted on
ztest 3.6G 3.6G 0B 100% /ztest
$ zfs list -o space ztest
NAME AVAIL USED USEDSNAP USEDDS USEDREFRESERV USEDCHILD
ztest 0B 3.63G 0B 3.62G 0B 672K
$ ls -l /ztest/dummy
-rw-r--r-- 1 root wheel 3891134464 Dec 22 17:43 /ztest/dummy
$ zpool export ztest
$ ls -l /boot/kernel/kernel
-r-xr-xr-x 2 root wheel 29343392 Nov 4 10:27 /boot/kernel/kernel
$ dd if=/boot/kernel/kernel of=/dev/gpt/tt1 oseek=1000000
dd: /dev/gpt/tt1: Invalid argument
57311+1 records in
57311+0 records out
29343232 bytes transferred in 21.647581 secs (1355497 bytes/sec)
$
读取损坏数据部分
为了确认是否发生错误，仅使用 da1 一侧进行导入。由于这是 USB 硬盘，因此物理上拔掉 da2 会更容易。
$ zpool import
pool: ztest
id: 6304409293823647838
state: DEGRADED
status: One or more devices are missing from the system.
action: The pool can be imported despite missing or damaged devices. The
fault tolerance of the pool may be compromised if imported.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
config:
ztest DEGRADED
mirror-0 DEGRADED
gpt/tt1 ONLINE
gpt/tt2 UNAVAIL cannot open
无法访问 da2 侧的 gpt/tt2。将继续导入 ztest。
$ zpool import ztest
$ zpool status ztest
pool: ztest
state: DEGRADED
status: One or more devices could not be opened. Sufficient replicas exist for
the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
config:
NAME STATE READ WRITE CKSUM
ztest DEGRADED 0 0 0
mirror-0 DEGRADED 0 0 0
gpt/tt1 ONLINE 0 0 0
13953643250226400519 UNAVAIL 0 0 0 was /dev/gpt/tt2
errors: No known data errors
$ df /ztest
Filesystem 512-blocks Used Avail Capacity Mounted on
ztest 7601264 7601024 240 100% /ztest
$ ls /ztest
dummy
#
只有一个驱动器，但/ztest/dummy 确实存在。那么让我们实际读取它。为了使数据内容可见，我们将使用 hd 命令进行读取。
$ zpool import
pool: ztest
id: 6304409293823647838
state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:
ztest ONLINE
mirror-0 ONLINE
gpt/tt1 ONLINE
gpt/tt2 ONLINE
GPT / TT2 端目前处于在线状态。现在将导入 ztest。
$ zpool import ztest
$ zpool status ztest
pool: ztest
state: ONLINE
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 0
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$
$ zpool status ztest
pool: ztest
state: ONLINE
scan: resilvered 432K in 00:00:01 with 0 errors on Fri Dec 23 11:14:23 2022
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 0
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$
使用 scrub 检查磁盘完整性
因为 ZFS 可能存在无法读取的部分，所以执行 scrub 以确认完整性。
$ zpool scrub ztest
$ zpool status ztest
pool: ztest
state: ONLINE
scan: scrub in progress since Fri Dec 23 11:18:02 2022
3.62G scanned at 530M/s, 378M issued at 54.0M/s, 3.62G total
0B repaired, 10.18% done, 00:01:01 to go
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 0
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$
等待 scrub 完成后，再查看状态。
$ zpool status ztest
pool: ztest
state: ONLINE
status: One or more devices has experienced an unrecoverable error. An
attempt was made to correct the error. Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
using 'zpool clear' or replace the device with 'zpool replace'.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-9P
scan: scrub repaired 15.8M in 00:01:06 with 0 errors on Fri Dec 23 11:19:08 2022
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 130
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$
$ zpool create -O atime=off ztest mirror gpt/tt1 gpt/tt2
$ dd if=/dev/zero of=/ztest/dummy bs=1m
dd: /ztest/dummy: No space left on device
3711+0 records in
3710+1 records out
3891134464 bytes transferred in 153.170356 secs (25403966 bytes/sec)
$ zpool export ztest
$ dd if=/boot/kernel/kernel of=/dev/gpt/tt1 oseek=1000000
dd: /dev/gpt/tt1: Invalid argument
57311+1 records in
57311+0 records out
29343232 bytes transferred in 21.643263 secs (1355767 bytes/sec)
$ zpool import ztest
$ zpool scrub ztest
$ zpool status ztest
pool: ztest
state: ONLINE
status: One or more devices has experienced an unrecoverable error. An
attempt was made to correct the error. Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
using 'zpool clear' or replace the device with 'zpool replace'.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-9P
scan: scrub repaired 27.9M in 00:01:06 with 0 errors on Mon Dec 26 10:55:49 2022
config:
NAME STATE READ WRITE CKSUM
ztest ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gpt/tt1 ONLINE 0 0 227
gpt/tt2 ONLINE 0 0 0
errors: No known data errors
$ zpool export ztest
由于导出成功，我将物理地移除 da2 端口，尝试导入并读取 da1 端口。
$ zpool import
pool: ztest
id: 11275383091719095959
state: DEGRADED
status: One or more devices are missing from the system.
action: The pool can be imported despite missing or damaged devices. The
fault tolerance of the pool may be compromised if imported.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
config:
ztest DEGRADED
mirror-0 DEGRADED
gpt/tt1 ONLINE
gpt/tt2 UNAVAIL cannot open
$ zpool import ztest
$ hd /ztest/dummy
00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
e7ee0000
$ zpool export ztest
