1、運行/usr/contrib/bin/crashinfo（根據(jù)第二步實際情況） | more，信息中注意類似如下內(nèi)容：
==================
= Memory Globals =
==================

Note: "freemem" was resynced with freemem caches: was 169536, now 168628

Physical Memory = 2096640 pages (8.00 GB) //物理內(nèi)存總量
Free Memory = 168628 pages (658.70 MB)//空閑內(nèi)存
Average Free Memory = 169403 pages (661.73 MB)//平均空閑內(nèi)存
gpgslim = 7168 pages (28.00 MB)
lotsfree = 32768 pages (128.00 MB)
desfree = 7168 pages (28.00 MB)
minfree = 3328 pages (13.00 MB)
**************物理內(nèi)存使用率=（物理內(nèi)存總量-空閑內(nèi)存）/物理內(nèi)存總量***************
========================
= Buffer Cache Globals =
========================

dbc_max_pct = 50 %
dbc_min_pct = 5 %
dbc current pct = 50.0 %
bufpages = 1048320 pages (4.00 GB)
Number of buf headers = 557940

fixed_size_cache = 0
dbc_parolemem = 0
dbc_stealavg = 0
dbc_ceiling = 1048320 pages (4.00 GB)
dbc_nbuf = 52416
dbc_bufpages = 104832 pages (409.50 MB)
dbc_vhandcredit = 11403
orignbuf = 0
origbufpages = 0 pages

====================
= Swap Information =
====================

swapinfo -mt emulation
======================

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 16384 0 16098 0% 0 - 1 LVM vg00/lv2
reserve - 2141 -2141
memory 6460 4928 1532 76%
total 22844 7069 15489 31% - 0 -
*****************SWAP內(nèi)存使用率就是total的PCT值：31%*************************
2、CPU的使用率可以從top參數(shù)得出：
System: JXCNMD1 Fri Aug 17 10:25:02 2007
Load averages: 0.35, 0.41, 0.44
311 processes: 257 sleeping, 53 running, 1 zombie
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 0.74 8.8% 3.8% 2.0% 85.5% 0.0% 0.0% 0.0% 0.0%
1 0.17 4.4% 6.2% 10.2% 79.3% 0.0% 0.0% 0.0% 0.0%
2 0.12 3.8% 1.0% 1.0% 94.2% 0.0% 0.0% 0.0% 0.0%
3 0.36 0.0% 70.9% 28.1% 1.0% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 0.35 4.2% 20.6% 10.2% 65.1% 0.0% 0.0% 0.0% 0.0%
*****************系統(tǒng)一共4個CPU，每個CPU的使用率=100%-IDLE值*******************
3、top命令的一些解釋
問：
top中的幾個參數(shù)的意義能幫忙解釋一下嗎？
主要是對 free的計算方法不太理解，機器的物理內(nèi)存有256M，free中的33M是怎么計算出來
的呢？

Memory: 92764K (15880K) real, 65796K (13316K) virtual, 33684K free Page# 1/5

另外，SAM中有如下有關(guān)信息

xx x Processor xx Memory xx Operating System xx Network xx Dynamic x x
xx lqqqqqqqqqqqq/ qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqk x
xx xlqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqkx x
xx xxPhysical Memory: 256.2 MB xx x
xx xxReal Memory: xx x
xx xx Active: 21113.5 KB xx x
xx xx Total: 97083.5 KB xx x
xx xxVirtual Memory: xx x
xx xx Active: 16247.3 KB xx x
xx xx Total: 68390.7 KB xx x
xx xxFree Memory Pages: 6738 at 4 KB/page xx x
xx xxSwap Space: xx x
xx xx Avail: 1024 MB xx x
xx xx Used: 231 MB xxvx
xmqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqjx

其中的Virtual Memory和 Swap Space是什么關(guān)系呢？我想計算虛擬內(nèi)存的利用率該如何計算呢？


答：
top 只能看到進程所使用的內(nèi)存量，所以你看到的 92764K (15880K) real 就是所有進程所使用的內(nèi)存總和，這個內(nèi)存是指物理內(nèi)存，括號前那個值是Total Real Memory,括號內(nèi)是Active Real Memory, 這兩者的區(qū)別就在于Active Real Memory的值只是分配給那些已經(jīng)在run queue或者正在運行的進程的Real Memory,而Total Real Memory 包括所有的進程。
對于后一項值 65796K (13316K) virtual 的解釋也是同樣的，不過這個值代表了Virtual Memory（一般為建在Disk上的Swap空間，當(dāng)然你要問了，我的Swap空間可不止這么些啊 by executing ‘swapinfo‘， 沒錯，Swap空間是大于這里的Total Vitual Memory的，但我前面說了，這里的值只是計算的分配給進程的），最后一項33684K free 到確確實實是Free 的Memory，它等于Physical Mem - kernel used - user used - buffer cache。


下面是對SAM->;Performance Monitor ->; System Property ->; Memory的顯示結(jié)果的解釋

Physical Memory 256.2 MB 實際物理內(nèi)存大小
Real Memory
Active: 21113.5 KB 同 top （當(dāng)然這里舉的例子由于有時間差，所以看上去不大一致）
Total: 97083.5 KB 同 top
Virtual Memory:
Active: 16247.3 KB 同 top
Total: 68390.7 KB 同 top
Free Memory Pages: 6738 at 4 KB/page 6738 * 4 就是 top 顯示出來的結(jié)果
Swap Space:
Avail: 1024 MB 同Swapinfo中 dev filesystem 總和（一般不會用到Pseudo Memory)，為實際Swap Space 的大小。
Used: 231 MB 同Swapinfo中的Reserve, 為系統(tǒng)在創(chuàng)建進程時為該進程預(yù)留的Swap 空間總和）