linux 4G内存，只认到2G

发布于 2022-10-15 08:57:27 字数 6909 浏览 24 评论 0

装了二条2G的内存，系统上只认到2G。
版本 18246。
[root@apache17 WebRoot4]# cat /proc/meminfo
MemTotal: 2073948 kB
MemFree: 1944128 kB
Buffers: 6268 kB
Cached: 51996 kB
SwapCached: 0 kB
Active: 54032 kB
Inactive: 32124 kB
HighTotal: 1178496 kB
HighFree: 1090908 kB
LowTotal: 895452 kB
LowFree: 853220 kB
SwapTotal: 2096440 kB
SwapFree: 2096440 kB
Dirty: 4 kB
Writeback: 0 kB
AnonPages: 28008 kB
Mapped: 11852 kB
Slab: 32136 kB
PageTables: 2376 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 3133412 kB
Committed_AS: 161360 kB
VmallocTotal: 116728 kB
VmallocUsed: 5144 kB
VmallocChunk: 111240 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
在硬件里是可以看到二条2G的内存的：
[root@apache17 WebRoot4]# dmidecode -t memory
# dmidecode 2.10
SMBIOS 2.4 present.

Handle 0x0005, DMI type 5, 24 bytes
Memory Controller Information
  Error Detecting Method: 8-bit Parity
  Error Correcting Capabilities:
  None
  Supported Interleave: One-way Interleave
  Current Interleave: One-way Interleave
  Maximum Memory Module Size: 1024 MB
  Maximum Total Memory Size: 4096 MB
  Supported Speeds:
  Other
  Supported Memory Types:
  Other
  Memory Module Voltage: 5.0 V
  Associated Memory Slots: 4
  0x0006
  0x0007
  0x0008
  0x0009
  Enabled Error Correcting Capabilities:
  None

Handle 0x0006, DMI type 6, 12 bytes
Memory Module Information
  Socket Designation: A0
  Bank Connections: 1
  Current Speed: Unknown
  Type: Other
  Installed Size: 2048 MB (Single-bank Connection)
  Enabled Size: 2048 MB (Single-bank Connection)
  Error Status: OK

Handle 0x0007, DMI type 6, 12 bytes
Memory Module Information
  Socket Designation: A1
  Bank Connections: 2
  Current Speed: Unknown
  Type: Other
  Installed Size: 2048 MB (Single-bank Connection)
  Enabled Size: 2048 MB (Single-bank Connection)
  Error Status: OK

Handle 0x0008, DMI type 6, 12 bytes
Memory Module Information
  Socket Designation: A2
  Bank Connections: 3
  Current Speed: Unknown
  Type: Unknown
  Installed Size: Not Installed
  Enabled Size: Not Installed
  Error Status: OK

Handle 0x0009, DMI type 6, 12 bytes
Memory Module Information
  Socket Designation: A3
  Bank Connections: 4
  Current Speed: Unknown
  Type: Unknown
  Installed Size: Not Installed
  Enabled Size: Not Installed
  Error Status: OK

Handle 0x001A, DMI type 16, 15 bytes
Physical Memory Array
  Location: System Board Or Motherboard
  Use: System Memory
  Error Correction Type: None
  Maximum Capacity: 4 GB
  Error Information Handle: Not Provided
  Number Of Devices: 4

Handle 0x001B, DMI type 17, 27 bytes
Memory Device
  Array Handle: 0x001A
  Error Information Handle: Not Provided
  Total Width: 64 bits
  Data Width: 64 bits
  Size: 2048 MB
  Form Factor: DIMM
  Set: None
  Locator: A0
  Bank Locator: Bank0/1
  Type: Unknown
  Type Detail: None
  Speed: 800 MHz
  Manufacturer:
  Serial Number:
  Asset Tag:
  Part Number:

Handle 0x001C, DMI type 17, 27 bytes
Memory Device
  Array Handle: 0x001A
  Error Information Handle: Not Provided
  Total Width: 64 bits
  Data Width: 64 bits
  Size: 2048 MB
  Form Factor: DIMM
  Set: None
  Locator: A1
  Bank Locator: Bank2/3
  Type: Unknown
  Type Detail: None
  Speed: 800 MHz
  Manufacturer:
  Serial Number:
  Asset Tag:
  Part Number:

Handle 0x001D, DMI type 17, 27 bytes
Memory Device
  Array Handle: 0x001A
  Error Information Handle: Not Provided
  Total Width: Unknown
  Data Width: Unknown
  Size: No Module Installed
  Form Factor: DIMM
  Set: None
  Locator: A2
  Bank Locator: Bank4/5
  Type: Unknown
  Type Detail: None
  Speed: Unknown
  Manufacturer:
  Serial Number:
  Asset Tag:
  Part Number:

Handle 0x001E, DMI type 17, 27 bytes
Memory Device
  Array Handle: 0x001A
  Error Information Handle: Not Provided
  Total Width: Unknown
  Data Width: Unknown
  Size: No Module Installed
  Form Factor: DIMM
  Set: None
  Locator: A3
  Bank Locator: Bank6/7
  Type: Unknown
  Type Detail: None
  Speed: Unknown
  Manufacturer:
  Serial Number:
  Asset Tag:
  Part Number:
网上有人说用：
1 给 uname -r
2 yum install kernel-PAE
我也更新内核了，
[root@apache17 WebRoot4]# uname -r
2.6.18-238.9.1.el5.centos.plusPAE
[root@apache17 WebRoot4]# uname -a
Linux apache17 2.6.18-238.9.1.el5.centos.plusPAE #1 SMP Tue Apr 12 21:38:49 EDT 2011 i686 i686 i386 GNU/Linux
内核也编译过，选择了支持16G了。
那位高人指教一下。