一台LINUX机器，是PAE内核，突然只能ping通，但无法telnet .
重新启动后，可以登录，但内存变为2G，如下：
[root@SCMMSC3_02 log]# more /proc/meminfo
MemTotal: 2070060 kB
MemFree: 51696 kB
Buffers: 8440 kB
Cached: 1659756 kB
SwapCached: 0 kB
Active: 957968 kB
Inactive: 960476 kB
HighTotal: 1173944 kB
HighFree: 1732 kB
LowTotal: 896116 kB
LowFree: 49964 kB
SwapTotal: 8385760 kB
SwapFree: 8385668 kB
Dirty: 205752 kB
Writeback: 48 kB
AnonPages: 250348 kB
Mapped: 83932 kB
Slab: 46452 kB
PageTables: 4608 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 9420788 kB
Committed_AS: 1585968 kB
VmallocTotal: 116728 kB
VmallocUsed: 7496 kB
VmallocChunk: 109112 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
[root@SCMMSC3_02 log]# vmstat 2 10
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 92 53080 8228 1659048 0 0 679 194 967 969 2 5 89 4 0
1 0 92 51716 8244 1661008 0 0 0 64 4618 5567 2 2 95 0 0
2 0 92 61664 8048 1649820 0 0 0 16 4329 8487 10 18 71 1 0
1 0 92 60424 8064 1651540 0 0 0 2332 4587 6457 10 7 81 2 0
1 1 92 51392 8120 1661144 0 0 4892 58 5055 5496 3 5 85 8 0
0 0 92 54728 8240 1658044 0 0 558 3128 4712 5342 4 7 82 8 0
1 0 92 53116 8248 1659660 0 0 0 164 4264 6560 2 4 93 0 0
0 0 92 54196 8268 1658240 0 0 0 40 4265 6532 5 13 81 0 0
1 0 92 53080 8276 1659896 0 0 0 2110 4438 4794 2 2 95 2 0
0 0 92 54080 8296 1658712 0 0 0 98 4439 5657 1 2 97 1 0
系统日志：Mar 15 15:38:23 SCMMSC3_02 kernel: Memory: 2067480k/2093056k available (2040k kernel code, 22732k reserved, 842k data, 232k init, 1173944k highmem)
同时系统日志没有报错，只是报如下：
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8900000-b89fffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: b8d00000-b8dfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:03:00.2
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:25 SCMMSC3_02 hpiod: 1.6.7 accepting connections at 2208...
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:02:00.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8900000-b89fffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: b8d00000-b8dfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:02:01.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:02:02.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: 3000-3fff
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8000000-b88fffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:01:00.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: 3000-3fff
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8000000-b89fffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: b8d00000-b8dfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:01:00.3
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: 2000-2fff
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8a00000-b8bfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: b8c00000-b8cfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:02.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: 2000-3fff
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: b8000000-b8cfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: b8d00000-b8dfffff
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:03.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:04.0
Mar 15 15:38:25 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:25 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:05.0
Mar 15 15:38:26 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:06.0
Mar 15 15:38:26 SCMMSC3_02 kernel: IO window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: MEM window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PREFETCH window: disabled.
Mar 15 15:38:26 SCMMSC3_02 kernel: PCI: Bridge: 0000:00:07.0
Mar 15 15:38:26 SCMMSC3_02 kernel: IO window: disabled.
是什么原因，导致内存减少了呢，同时最后的日志是什么意思呢？非常感谢！
liachun 于 2011-03-17 12:32:37发表:
去试一下，谢谢！
pl_014 于 2011-03-16 20:21:49发表:
这个日志不会看，楼主的情况比我的还要糟糕，我的4G内存只认3.2G（无论普通32位内核、32位PAE内核，还是纯64位内核），可能要看看内核bug，也有可能是内存或插槽本身的问题。
xiongda1016 于 2011-03-16 15:24:55发表:
Linux在启动进程后会有一些进程碎片，执行下面命令试下看看
echo 1 > /proc/sys/vm/drop_caches
echo 2 > /proc/sys/vm/drop_caches
echo 3 > /proc/sys/vm/drop_caches
echo 0 > /proc/sys/vm/swappiness