我刚刚创建了一个运行的 Amazon AWS EC2 实例RHEL7：
[root@ip-10-184-161-46 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.0 (Maipo)
[root@ip-10-184-161-46 ~]#
尽管我选择了10GB存储容量，但出于某种原因，我只看到6GB可以立即使用的内容：
[root@ip-10-184-161-46 ~]# mount | grep xfs | grep -v selinux
/dev/xvda1 on / type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
[root@ip-10-184-161-46 ~]# df -h | grep xvda
/dev/xvda1 6.0G 2.2G 3.9G 37% /
[root@ip-10-184-161-46 ~]# fdisk -l /dev/xvda
Disk /dev/xvda: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
Disk identifier: 0x0000b85c
Device Boot Start End Blocks Id System
/dev/xvda1 * 2048 12584959 6291456 83 Linux
[root@ip-10-184-161-46 ~]#
这是我做的：
[root@ip-10-164-175-246 ~]# fdisk -l /dev/xvda
Disk /dev/xvda: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
Disk identifier: 0x0000b85c
Device Boot Start End Blocks Id System
/dev/xvda1 * 2048 12584959 6291456 83 Linux
/dev/xvda2 12584960 20971519 4193280 83 Linux
[root@ip-10-164-175-246 ~]# xfs_growfs /
meta-data=/dev/xvda1 isize=256 agcount=4, agsize=393216 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=1572864, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@ip-10-164-175-246 ~]# df -h | grep xvda
/dev/xvda1 6.0G 2.3G 3.8G 38% /
[root@ip-10-164-175-246 ~]#
我的其他文件在哪里4GB？我以为运行xfs_growfs /会增加我的分区的大小xfs。
我究竟做错了什么？
答案1
有趣的是，前几天我发现 EC2 上的 RHEL 实例只分配了 10GB 空间中的 6GB 左右后，就做了同样的事情……
[root@ip-172-31-20-177 ~]# xfs_info /
meta-data=/dev/xvda1 isize=256 agcount=4, agsize=393216 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=1572864, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
这里的问题是你创建了一个第二分割。
相反，您应该调整第一个分区的大小。
因此，你将使用fdisk删除第二个分区，然后删除并重新创建第一个分区同时。fdisk默认值将导致它填满磁盘（并正确对齐）。
启动fdisk并删除分区：
[root@ip-172-31-20-177 ~]# fdisk /dev/xvda
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/xvda: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
Disk identifier: 0x0000b85c
Device Boot Start End Blocks Id System
/dev/xvda1 * 2048 12584959 6291456 83 Linux
Command (m for help): d
Selected partition 1
Partition 1 is deleted
现在使用所有默认值重新创建分区，这将最大化其大小：
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519):
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): p
Disk /dev/xvda: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
Disk identifier: 0x0000b85c
Device Boot Start End Blocks Id System
/dev/xvda1 2048 20971519 10484736 83 Linux
保存新的分区表：
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
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.
重新启动时，文件系统应会自动调整大小cloud-init。如果没有，您可以使用xfs_growfs /手动扩大文件系统。
[root@ip-172-31-20-177 ~]# xfs_info /
meta-data=/dev/xvda1 isize=256 agcount=7, agsize=393216 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=2621184, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@ip-172-31-20-177 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/xvda1 10474496 818560 9655936 8% /
答案2
您已将 10GB 磁盘 xvda 划分为两个分区：xvda1 为 6GB，xvda2 为 4GB。因此，其他 4GB 位于 xvda2 中，如果您想使用它，可以将其挂载到某个位置。