记忆缺失了？Centos 6 x64

Question

在将服务器从centos 4升级到centos 6之后，12 Gb中只有8 Gb可供系统使用；我认为有些是错误的，但情况并非如此(我试图用另一台服务器处理内存)，我有6x2GB的DDR DIMM；

free
             total       used       free     shared    buffers     cached
Mem:       8195024     560508    7634516          0      37388     169116
-/+ buffers/cache:     354004    7841020
Swap:      4200956          0    4200956

和/proc/meminfo

cat /proc/meminfo
MemTotal:        8195024 kB
MemFree:         7702732 kB
Buffers:           29232 kB
Cached:           106368 kB
SwapCached:            0 kB
Active:            93684 kB
Inactive:         107164 kB
Active(anon):      65476 kB
Inactive(anon):     1032 kB
Active(file):      28208 kB
Inactive(file):   106132 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       4200956 kB
SwapFree:        4200956 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:         65244 kB
Mapped:            33532 kB
Shmem:              1264 kB
Slab:             211304 kB
SReclaimable:      24852 kB
SUnreclaim:       186452 kB
KernelStack:        1960 kB
PageTables:        11336 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     8298468 kB
Committed_AS:     346860 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      321300 kB
VmallocChunk:   34359408376 kB
HardwareCorrupted:     0 kB
AnonHugePages:      8192 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       10176 kB
DirectMap2M:     8378368 kB

以下是一些产出：

dmidecode -t 17
#dmidecode 2.10
SMBIOS 2.3 present.

Handle 0x003A, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 2048 MB
Form Factor: DIMM
Set: None
Locator: A0
Bank Locator: Bank0/1
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

Handle 0x003B, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 2048 MB
Form Factor: DIMM
Set: None
Locator: A1
Bank Locator: Bank2/3
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

Handle 0x003C, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 2048 MB
Form Factor: DIMM
Set: None
Locator: A2
Bank Locator: Bank4/5
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

Handle 0x003D, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 2048 MB
Form Factor: DIMM
Set: None
Locator: A3
Bank Locator: Bank6/7
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

Handle 0x003E, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 16384 MB
Form Factor: DIMM
Set: None
Locator: A4
Bank Locator: Bank8/9
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

Handle 0x003F, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0039
Error Information Handle: Not Provided
Total Width: 144 bits
Data Width: 128 bits
Size: 16384 MB
Form Factor: DIMM
Set: None
Locator: A5
Bank Locator: Bank10/11
Type: DDR
Type Detail: Synchronous
Speed: 400 MHz
Manufacturer: None
Serial Number: None
Asset Tag: None
Part Number: None

最后两个显示为16384 as，应该是2048 as。

我还设置了lm_sensors + i2c-tools：

decode-dimms
# decode-dimms version 5929 (2011-02-16 14:58:38 +0100)

Memory Serial Presence Detect Decoder
By Philip Edelbrock, Christian Zuckschwerdt, Burkart Lingner,
Jean Delvare, Trent Piepho and others


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0050
Guessing DIMM is in                             bank 1

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xE2)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T, 2T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
                                                7.5 ns at CAS 2
Maximum Access Time                             0.5 ns at CAS 3
                                                0.5 ns at CAS 2.5
                                                0.5 ns at CAS 2
Module Height                                   1.125" to 1.25"

---=== Manufacturing Information ===---
Manufacturer                                    Infineon (former Siemens)
Manufacturing Location Code                     V
Part Number                                     72D256220GBR5B    
Revision Code                                   0x030C
Manufacturing Date                              2006-W01
Assembly Serial Number                          0x0600C212


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0051
Guessing DIMM is in                             bank 2

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xB5)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
Maximum Access Time                             0.65 ns at CAS 3
                                                0.7 ns at CAS 2.5

---=== Manufacturing Information ===---
Manufacturer                                    Kingston
Manufacturing Location Code                     0x04
Part Number                                     Undefined
Manufacturing Date                              2006-W14
Assembly Serial Number                          0x08108AB0


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0052
Guessing DIMM is in                             bank 3

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xE2)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T, 2T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
                                                7.5 ns at CAS 2
Maximum Access Time                             0.5 ns at CAS 3
                                                0.5 ns at CAS 2.5
                                                0.5 ns at CAS 2
Module Height                                   1.125" to 1.25"

---=== Manufacturing Information ===---
Manufacturer                                    Infineon (former Siemens)
Manufacturing Location Code                     V
Part Number                                     72D256220GBR5B    
Revision Code                                   0x030C
Manufacturing Date                              2006-W01
Assembly Serial Number                          0x0600AE27


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0053
Guessing DIMM is in                             bank 4

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xB5)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
Maximum Access Time                             0.65 ns at CAS 3
                                                0.7 ns at CAS 2.5

---=== Manufacturing Information ===---
Manufacturer                                    Kingston
Manufacturing Location Code                     0x04
Part Number                                     Undefined
Manufacturing Date                              2006-W14
Assembly Serial Number                          0x011046B4


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0054
Guessing DIMM is in                             bank 5

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xE2)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T, 2T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
                                                7.5 ns at CAS 2
Maximum Access Time                             0.5 ns at CAS 3
                                                0.5 ns at CAS 2.5
                                                0.5 ns at CAS 2
Module Height                                   1.125" to 1.25"

---=== Manufacturing Information ===---
Manufacturer                                    Infineon (former Siemens)
Manufacturing Location Code                     V
Part Number                                     72D256220GBR5B    
Revision Code                                   0x030C
Manufacturing Date                              2006-W01
Assembly Serial Number                          0x04048112


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/2-0055
Guessing DIMM is in                             bank 6

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0xE2)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR SDRAM
SPD Revision                                    1.0

---=== Memory Characteristics ===---
Maximum module speed                            400MHz (PC3200)
Size                                            2048 MB
Voltage Interface Level                         SSTL 2.5V
Module Configuration Type                       ECC
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
tCL-tRCD-tRP-tRAS                               3-3-3-8
Supported CAS Latencies                         3T, 2.5T, 2T
Supported CS Latencies                          0
Supported WE Latencies                          1
Minimum Cycle Time                              5 ns at CAS 3
                                                6 ns at CAS 2.5
                                                7.5 ns at CAS 2
Maximum Access Time                             0.5 ns at CAS 3
                                                0.5 ns at CAS 2.5
                                                0.5 ns at CAS 2
Module Height                                   1.125" to 1.25"

---=== Manufacturing Information ===---
Manufacturer                                    Infineon (former Siemens)
Manufacturing Location Code                     V
Part Number                                     72D256220GBR5B    
Revision Code                                   0x030C
Manufacturing Date                              2006-W01
Assembly Serial Number                          0x0600BA20


Number of SDRAM DIMMs detected and decoded: 6

这里所有的字节都有2048 OK并且被检测到(字节的EEprom校验和0-62都是正常的)

今晚我要启动一个记忆测试

谢谢你的暗示

编辑:我当然是64位元：

uname -r
2.6.32-71.el6.x86-64

Answer 1

如果它仅在POST上显示为8GB，那么它就不是一个CentOS问题。很可能是在升级过程中发生了一些与硬件相关的事情，或者是不久前发生了一些事情，而你并没有注意到。

您应该检查以确保您正在为您的硬件运行最新的BIOS修订版。如果这还不够，你应该联系他们寻求支持。