EC2 驱动器不是 EBS 卷大小

Question

我有一个 EC2 实例，我为其创建了一个 500GB 的 EBS 卷。不幸的是，EC2 实例显示只有 8GB 可用。

我只有一个驱动器，这是正确的。

[root@ip-10-244-134-250 ~]# ls -la /dev/x*
brw-rw---- 1 root disk 202, 1 Aug  7 08:54 /dev/xvda1

但是，那个驱动器只有 8GB

[root@ip-10-244-134-250 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/xvda1            8.0G  1.3G  6.7G  16% /
tmpfs                 3.7G     0  3.7G   0% /dev/shm

但是， fdisk 和 /proc/partitions 都显示正确的大小

[root@ip-10-244-134-250 ~]# fdisk -l

Disk /dev/xvda1: 536.9 GB, 536870912000 bytes
255 heads, 63 sectors/track, 65270 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/xvda1 doesn't contain a valid partition table

[root@ip-10-244-134-250 ~]# cat /proc/partitions 
major minor  #blocks  name

 202        1  524288000 xvda1

任何帮助将不胜感激，谢谢。

Answer 1

如果根文件系统是 ext3 或 ext4，则运行：

sudo resize2fs /dev/xvda1

如果根文件系统是 xfs（不太常见），则运行：

sudo xfs_growfs /

如果您以 root 身份登录，则可以省略“sudo”。

这些命令应该在系统运行和文件系统挂载时运行。

EBS 卷不包含分区表是标准的。EBS 卷通常被格式化为一个没有分区的完整文件系统。

Answer 2

在专门为更改 EBS 卷大小的人重新调整大小之前，这里的答案似乎缺少几个步骤。如果您使用快照创建 EBS 或使用某些 AMI，您将需要扩展磁盘 (xvda)、扩展分区 (xvda1)，然后扩展文件系统 (/)。

如果我没看错，你的磁盘看起来像这样：

/dev/xvda
|__/dev/xvda1__|______________ Free space______________|

它需要看起来像这样：

/dev/xvda
|______________________/dev/xvda1______________________|

之后，运行resize2fs将增长到 内的新空间xvda1，使用fdisk我们可以通过删除和再次创建它来增加块大小并使分区可引导。它所需要的只是重新启动。在大多数情况下，如果您使用相同的启动柱面，它应该不会影响您的数据，但请注意，重新创建分区时的任何错误都将导致丢失所有数据和/或服务器不会重新启动。 我建议将此作为新创建实例的第一步。否则拍摄您的 EC2 EBS 存储/等的快照。

我在下面的块中用 <<#>> 标记了步骤，所以它们不是命令的一部分。您需要 root 权限，因此如果您不是 root，请执行“sudo sh”。

<<1>> Look at the filesystem, it is 6G
<<2>> Look at the disk and the partition, the disk is 21.5 GB but the partition is 6 GB (6291456 blocks)
<<3>> Start fdisk for that disk (xvda, so not the partition xvda1)
<<4>> Switch to sector display.
<<5>> Print the partition(s), and remember the start sector (2048 in the example).
<<6>> Delete the partition.
<<7>> Create a new partition.
<<8>> Make it primary.
<<9>> First partition.
<<10>> Enter the old start sector, do NOT make any typo here!!! (2048 in the example) 
<<11>> Hit enter to accept the default (this is the remainder of the disk)
<<12>> Print the changes and make sure the start sector is ok, if not restart at <<6>>
<<13>> Make the partition bootable. do NOT forget this!!!
<<14>> Enter your partition number (1 in the example)
<<15>> Write the partition info back, this will end the fdisk session.
<<16>> Reboot the server, and wait for it to come up (this may take longer than usual).
<<17>> Verify the filesystem size.
<<18>> If the filesystem is not around 20Gb as expected, you can use this command.


# df -h  <<1>>

Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1      6.0G  2.0G  3.7G  35% / 
tmpfs            15G     0   15G   0% /dev/shm

# fdisk -l  <<2>>

Disk /dev/xvda: 21.5 GB, 21474836480 bytes
97 heads, 17 sectors/track, 25435 cylinders
Units = cylinders of 1649 * 512 = 844288 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003b587

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *           2        7632     6291456   83  Linux

# fdisk /dev/xvda  <<3>>

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): u  <<4>>
Changing display/entry units to sectors

Command (m for help): p  <<5>>

Disk /dev/xvda: 21.5 GB, 21474836480 bytes
97 heads, 17 sectors/track, 25435 cylinders, total 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003b587

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *        2048    12584959     6291456   83  Linux

Command (m for help): d  <<6>>
Selected partition 1

Command (m for help): n  <<7>>
Command action
   e   extended
   p   primary partition (1-4)
p  <<8>>
Partition number (1-4): 1  <<9>>
First sector (17-41943039, default 17): 2048  <<10>>
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): <<11>>
Using default value 41943039

Command (m for help): p <<12>>

Disk /dev/xvda: 21.5 GB, 21474836480 bytes
97 heads, 17 sectors/track, 25435 cylinders, total 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003b587

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1            2048    41943039    20970496   83  Linux

Command (m for help): a  <<13>>
Partition number (1-4): 1  <<14>>


Command (m for help): w  <<15>>
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: ...
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

# reboot  <<16>>

<wait>

# df -h  <<17>>
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1       20G  2.0G   17G  11% / 
tmpfs            15G     0   15G   0% /dev/shm

# resize2fs /dev/xvda1  <<18>>
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/xvda1 is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/xvda1 to 5242624 (4k) blocks.
The filesystem on /dev/xvda1 is now 5242624 blocks long.

root@vs120 [~]#  df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1       20G  7.8G   11G  42% /
tmpfs           498M     0  498M   0% /dev/shm
/usr/tmpDSK     399M   11M  368M   3% /tmp
root@vs120 [~]#