適用於:✔️ Linux VM ✔️ 彈性擴展集
本文示範如何透過 Azure 入口網站將新的及現有的磁碟連結到 Linux 虛擬機器。 您也可以在 Azure 入口網站中將資料磁碟連結到 Windows VM。
適用於:✔️ Linux VM ✔️ 彈性擴展集
本文示範如何透過 Azure 入口網站將新的及現有的磁碟連結到 Linux 虛擬機器。 您也可以在 Azure 入口網站中將資料磁碟連結到 Windows VM。
將磁碟附加至 VM 之前,請檢閱下列提示︰
虛擬機器的大小會控制您可以連接的資料磁碟數目。 如需詳細資訊,請參閱 虛擬機器的大小。
執行下列步驟:
移至 Azure 入口網站尋找 VM。 搜尋並選取 [虛擬機器]。
從清單中選取您想要將磁碟連結至的 VM。
在 [虛擬機] 頁面的 [設定] 下,選取 [磁盘]。
執行下列步驟:
執行下列步驟:
在 [資料磁碟] 下的 [磁碟] 窗格,選取 [連結現有的磁碟]。
選取 [磁碟名稱] 的下拉式功能表,然後從可用的受控磁碟清單中選取磁碟。
選取 [儲存] 以附加現有的受控磁碟並更新 VM 組態︰
若要分割、格式化和掛接新磁碟以供 Linux VM 使用,請使用 SSH 登入您的 VM。 如需詳細資訊,請參閱如何在 Azure 上搭配使用 SSH 與 Linux。 下列的範例連線至了一個公用 IP 位址為 10.123.123.25,使用者名稱為 azureuser 的 VM:
ssh azureuser@10.123.123.25
連線到 VM 之後,您需要尋找磁碟。 在此範例中,我們會使用 lsblk
來列出磁碟。
lsblk -o NAME,HCTL,SIZE,MOUNTPOINT | grep -i "sd"
The output is similar to the following example:
sda 0:0:0:0 30G
├─sda1 29.9G /
├─sda14 4M
└─sda15 106M /boot/efi
sdb 1:0:1:0 14G
└─sdb1 14G /mnt
sdc 3:0:0:0 4G
In this example, the disk that was added was sdc
. It's a LUN 0 and is 4GB.
For a more complex example, here's what multiple data disks look like in the portal:
In the image, you can see that there are 3 data disks: 4 GB on LUN 0, 16GB at LUN 1, and 32G at LUN 2.
Here's what that might look like using lsblk
:
sda 0:0:0:0 30G
├─sda1 29.9G /
├─sda14 4M
└─sda15 106M /boot/efi
sdb 1:0:1:0 14G
└─sdb1 14G /mnt
sdc 3:0:0:0 4G
sdd 3:0:0:1 16G
sde 3:0:0:2 32G
From the output of lsblk
you can see that the 4GB disk at LUN 0 is sdc
, the 16GB disk at LUN 1 is sdd
, and the 32G disk at LUN 2 is sde
.
Important
If you are using an existing disk that contains data, skip to mounting the disk. The following instructions will delete data on the disk.
If you're attaching a new disk, you need to partition the disk.
The parted
utility can be used to partition and to format a data disk.
parted
that is available for your distro.The following example uses parted
on /dev/sdc
, which is where the first data disk will typically be on most VMs. Replace sdc
with the correct option for your disk. We're also formatting it using the XFS filesystem.
sudo parted /dev/sdc --script mklabel gpt mkpart xfspart xfs 0% 100%
sudo mkfs.xfs /dev/sdc1
sudo partprobe /dev/sdc1
Use the partprobe
utility to make sure the kernel is aware of the new partition and filesystem. Failure to use partprobe
can cause the blkid or lslbk commands to not return the UUID for the new filesystem immediately.
Create a directory to mount the file system using mkdir
. The following example creates a directory at /datadrive
:
sudo mkdir /datadrive
Use mount
to then mount the filesystem. The following example mounts the /dev/sdc1 partition to the /datadrive
mount point:
sudo mount /dev/sdc1 /datadrive
To ensure that the drive is remounted automatically after a reboot, it must be added to the /etc/fstab file. It's also highly recommended that the UUID (Universally Unique Identifier) is used in /etc/fstab to refer to the drive rather than just the device name (such as, /dev/sdc1). If the OS detects a disk error during boot, using the UUID avoids the incorrect disk being mounted to a given location. Remaining data disks would then be assigned those same device IDs. To find the UUID of the new drive, use the blkid
utility:
sudo blkid
The output looks similar to the following example:
/dev/sda1: LABEL="cloudimg-rootfs" UUID="11111111-1b1b-1c1c-1d1d-1e1e1e1e1e1e" TYPE="ext4" PARTUUID="1a1b1c1d-11aa-1234-1a1a1a1a1a1a"
/dev/sda15: LABEL="UEFI" UUID="BCD7-96A6" TYPE="vfat" PARTUUID="1e1g1cg1h-11aa-1234-1u1u1a1a1u1u"
/dev/sdb1: UUID="22222222-2b2b-2c2c-2d2d-2e2e2e2e2e2e" TYPE="ext4" TYPE="ext4" PARTUUID="1a2b3c4d-01"
/dev/sda14: PARTUUID="2e2g2cg2h-11aa-1234-1u1u1a1a1u1u"
/dev/sdc1: UUID="33333333-3b3b-3c3c-3d3d-3e3e3e3e3e3e" TYPE="xfs" PARTLABEL="xfspart" PARTUUID="c1c2c3c4-1234-cdef-asdf3456ghjk"
Note
Improperly editing the /etc/fstab file could result in an unbootable system. If unsure, refer to the distribution's documentation for information on how to properly edit this file. You should create a backup of the /etc/fstab file is created before editing.
Next, open the /etc/fstab file in a text editor. Add a line to the end of the file, using the UUID value for the /dev/sdc1
device that was created in the previous steps, and the mountpoint of /datadrive
. Using the example from this article, the new line would look like the following:
UUID=33333333-3b3b-3c3c-3d3d-3e3e3e3e3e3e /datadrive xfs defaults,nofail 1 2
When you're done editing the file, save and close the editor.
Note
Later removing a data disk without editing fstab could cause the VM to fail to boot. Most distributions provide either the nofail and/or nobootwait fstab options. These options allow a system to boot even if the disk fails to mount at boot time. Consult your distribution's documentation for more information on these parameters.
The nofail option ensures that the VM starts even if the filesystem is corrupt or the disk does not exist at boot time. Without this option, you may encounter behavior as described in Cannot SSH to Linux VM due to FSTAB errors
您現在可以再次使用 lsblk
來查看磁碟和掛接點。
lsblk -o NAME,HCTL,SIZE,MOUNTPOINT | grep -i "sd"
輸出會如下所示:
sda 0:0:0:0 30G
├─sda1 29.9G /
├─sda14 4M
└─sda15 106M /boot/efi
sdb 1:0:1:0 14G
└─sdb1 14G /mnt
sdc 3:0:0:0 4G
└─sdc1 4G /datadrive
您可以看到 sdc
現在已掛接在 /datadrive
上。
有些 Linux 核心會支援 TRIM/UNMAP 作業以捨棄磁碟上未使用的區塊。 此功能主要用於通知 Azure 已刪除的頁面已不再有效且可予以捨棄。 此功能可節省根據已取用儲存體數目計費的磁碟費用,例如非受控標準磁碟和磁碟快照集。
有兩種方式可在 Linux VM 中啟用 TRIM 支援。 像往常一樣,請參閱您的散發套件以了解建議的方法︰
在 /etc/fstab 中使用 discard
掛接選項,例如:
```config
UUID=33333333-3b3b-3c3c-3d3d-3e3e3e3e3e3e /datadrive xfs defaults,discard 1 2
```
在某些情況下,discard
選項可能會影響效能。 或者,您也可以從命令列手動執行 fstrim
命令,或將它新增到 crontab 來定期執行︰
Ubuntu \(英文\)
sudo apt-get install util-linux
sudo fstrim /datadrive
RHEL
sudo yum install util-linux
sudo fstrim /datadrive
SUSE
sudo zypper install util-linux
sudo fstrim /datadrive