1、配置各種內核轉儲 dump撰寫者信息:Alin Fang (Fang YunlinMSN:G Talk:Blog:修改日期:22 Sep, 2008第一次修改版權:GNU聲明:本人實驗筆記,非權威文檔。如有錯誤請告知作者。十分感謝!實驗筆記:netdumpnetdump 需要兩臺機器配合。如果 client 端死機,則會把內存里面的信息 dump 到 server 。client:OS:Red Hat Enterprise Linux 4 update 7server:OS: Red Hat Enterprise Linux 4 update 7client 網絡環境 :rootstation

2、1 # ifconfigeth0 Link encap:Ethernet HWaddr 00:0C:29:22:61:B5inet addr:192.168.0.1 Bcast:192.168.255.255 Mask:255.255.0.0 inet6 addr: fe80:20c:29ff:fe22:61b5/64 Scope:LinkUP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:4 errors:0 dropped:0 overruns:0 frame:0TX packets:9 errors:0 dropped:0

3、 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:240 (240.0 b TX bytes:546 (546.0 bInterrupt:185 Base address:0x2000eth1 Link encap:Ethernet HWaddr 00:0C:29:22:61:BFinet6 addr: fe80:20c:29ff:fe22:61bf/64 Scope:LinkUP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:68 errors:0 droppe

4、d:0 overruns:0 frame:0TX packets:57 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:9962 (9.7 KiB TX bytes:7759 (7.5 KiBInterrupt:177 Base address:0x2080lo Link encap:Local Loopbackinet6 addr: :1/128 Scope:HostUP LOOPBACK RUNNING MTU:16436 Metric:1RX packets:8 errors:0 dr

5、opped:0 overruns:0 frame:0TX packets:8 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:560 (560.0 b TX bytes:560 (560.0 brootstation1 # routeKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface 10.66.0.0 * 255.255.254.0 U 0 0 0 eth1 169.254.0.0 * 255

6、.255.0.0 U 0 0 0 eth1 192.168.0.0 * 255.255.0.0 U 0 0 0 eth0 default 10.66.1.254 0.0.0.0 UG 0 0 0 eth1 rootstation1 #server 網絡環境:rootstation2 # ifconfigeth0 Link encap:Ethernet HWaddr 00:0C:29:32:64:A0inet6 addr: fe80:20c:29ff:fe32:64a0/64 Scope:LinkUP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX

7、 packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:9 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:0 (0.0 b TX bytes:546 (546.0 bInterrupt:185 Base address:0x2000eth1 Link encap:Ethernet HWaddr 00:0C:29:32:64:AAinet6 addr: fe80:20c:29ff:fe32:64aa/64 Scope:LinkUP

8、 BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:126 errors:0 dropped:0 overruns:0 frame:0TX packets:55 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:16122 (15.7 KiB TX bytes:7651 (7.4 KiBInterrupt:177 Base address:0x2080lo Link encap:Local Loopbackinet6 addr: :

9、1/128 Scope:HostUP LOOPBACK RUNNING MTU:16436 Metric:1RX packets:8 errors:0 dropped:0 overruns:0 frame:0TX packets:8 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:560 (560.0 b TX bytes:560 (560.0 brootstation2 # routeKernel IP routing tableDestination Gateway Genmask Flags

10、 Metric Ref Use Iface 10.66.0.0 * 255.255.254.0 U 0 0 0 eth1 169.254.0.0 * 255.255.0.0 U 0 0 0 eth1 192.168.0.0 * 255.255.0.0 U 0 0 0 eth0 default 10.66.1.254 0.0.0.0 UG 0 0 0 eth1 rootstation2 #配置 serverrootstation2 # rpm -q netdump-serverpackage netdump-server is not installedrootstation2 # mount

11、/dev/cdrom /media/mount: block device /dev/cdrom is write-protected, mounting read-onlyrootstation2 # cd /media/RedHat/RPMS/warning: netdump-server-0.7.16-14.i386.rpm: V3 DSA signature: NOKEY, key ID db42a60ePreparing. # 100% 1:netdump-server # 100% rootstation2 RPMS# service netdump-serverUsage: ne

12、tdump-server start|stop|status|restart|condrestartrootstation2 RPMS# service netdump-server startStarting netdump server: OK rootstation2 RPMS# chkconfig -level 35 netdump-server onrootstation2 RPMS# passwd netdumpChanging password for user netdump.New UNIX password:BAD PASSWORD: it is based on a di

13、ctionary wordRetype new UNIX password:passwd: all authentication tokens updated successfully.rootstation2 RPMS#安裝 netdump-server 會在系統里面添加 netdump 這個用戶。作為 netdump 時候傳輸數據之用。 但是并不會給這個用戶創建密碼。所以這個用戶默認是給鎖住的。因此記得給 netdump 這個 用戶分配密碼!配置 clientrootstation1 # rpm -q netdumprootstation1 # vi /etc/sysconfig/netd

14、ump指定 netdump-server 的 IP 地址rootstation1 # service netdump startnetdump10.66.0.114's password:initializing netdump OK initializing netconsole OK Message from syslogdstation1 at Mon Sep 22 17:47:38 2008 .station1 kernel: work console startup.rootstation1 #然后在 client 上模擬 crashrootstation1 # echo 1

15、 > /proc/sys/kernel/sysrqrootstation1 # echo c > /proc/sysrq-trigger然后 netdump 就給激活了。當 dump 完數據,機器自動重啟。在 server 上檢驗數據rootstation2 # cd /var/crash/rootstation2 crash# lltotal 16drwx- 2 netdump netdump 4096 Sep 22 18:05 192.168.0.1-2008-09-22-18:04 drwx- 2 netdump netdump 4096 Sep 22 17:48 magic

16、drwxr-xr-x 2 netdump netdump 4096 Aug 4 2007 scriptsrootstation2 crash# cd 192.168.0.1-2008-09-22-18:04/rootstation2 192.168.0.1-2008-09-22-18:04# lltotal 81656-rw- 1 netdump netdump 30592 Sep 22 18:05 log-rw- 1 netdump netdump 268439552 Sep 22 18:05 vmcorerootstation2 192.168.0.1-2008-09-22-18:04#

17、ll -htotal 80M-rw- 1 netdump netdump 30K Sep 22 18:05 log-rw- 1 netdump netdump 257M Sep 22 18:05 vmcorerootstation2 192.168.0.1-2008-09-22-18:04#vmcore 就是發生 crash 的時候內存里的數據。diskdumpdiskdump 在 Red Hat Enterprise Linux 4 update 4之前需要一塊單獨的硬盤。在 Red Hat Enterprise Linux 4 update 4以及之后,只需要一塊單獨的磁盤分區。試驗環境:

18、Red Hat Enterprise Linux 4 update 7原本采用 Red Hat Enterprise Linux 5 update 2,但是發現 diskdump 在 RHEL5以及更高版本上 被 kdump 所替代。試驗步驟先劃分一塊分區給 diskdump 。rootdhcp-0-084 # fdisk /dev/sdbDevice contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding a new DOS disklabel. Changes will rema

19、in in memory only,until you decide to write them. After that, of course, the previouscontent won't be recoverable.Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite Command (m for help: pDisk /dev/sdb: 4294 MB, 4294967296 bytes255 heads, 63 sectors/track, 522 cylinders

20、Units = cylinders of 16065 * 512 = 8225280 bytesDevice Boot Start End Blocks Id SystemCommand (m for help: nCommand actione extendedp primary partition (1-4pPartition number (1-4: 1First cylinder (1-522, default 1:Using default value 1Last cylinder or +size or +sizeM or +sizeK (1-522, default 522:Us

21、ing default value 522Command (m for help: wThe partition table has been altered!Calling ioctl( to re-read partition table.Syncing disks.partproberootdhcp-0-084 # partprobeWarning: Unable to open /dev/hdc read-write (Read-only file system. /dev/hdc has been opened read-only.No changes made to disk, e

22、xiting partprobe.rootdhcp-0-084 #我們用 /dev/sdb1作為 diskdump 的數據臨時存放點。編輯 diskdump 配置文件。rootdhcp-0-084 RPMS# rpm -qa | grep diskdump diskdumputils-1.4.1-5 rootdhcp-0-084 RPMS# vi /etc/sysconfig/diskdump DEVICE=/dev/sdb1 初始化并啟動 diskdump 服務. rootdhcp-0-084 # service diskdump initialformat Formatting dump

23、device: Do you want to format /dev/sdb1 (yes/NO? yes /dev/sdb1: 100.0% rootdhcp-0-084 # service diskdump restart Starting diskdump: OK rootdhcp-0-084 # chkconfig -level 35 diskdump on rootdhcp-0-084 # 然后模擬死機. rootdhcp-0-084 RPMS# echo 1 > /proc/sys/kernel/sysrq rootdhcp-0-084 RPMS# echo c > /p

24、roc/sysrq-trigger 此時 diskdump 開始工作.把內存中的數據 dump 到/dev/sdb1 中. diskdump 之后必須手動重啟機器. 重啟機器后,diskdump 會把/dev/sdb1 里面的數據拷到/var/crash 文件夾下. 檢查 diskdump 數據. rootdhcp-0-084 # cd /var/crash/ rootdhcp-0-084 crash# ll total 12 drwx- 2 root root 4096 Sep 22 19:52 127.0.0.1-2008-09-22-19:49 drwxr-xr-x 2 netdump

25、netdump 4096 Mar 25 23:33 scripts rootdhcp-0-084 crash# cd 127.0.0.1-2008-09-22-19:49/ rootdhcp-0-084 127.0.0.1-2008-09-22-19:49# ll -h total 86M -rw- 1 root root 513M Sep 22 19:52 vmcore rootdhcp-0-084 127.0.0.1-2008-09-22-19:49# kdump 實驗環境: client OS: Red Hat Enterprise Linux 5 update 2 client IP:

26、 10.66.0.157 server OS: Red Hat Enterprise Linux 4 update 7 server IP: 10.66.0.84 kdump 屬于 kexec-tools-1.102pre-21.el5 這個包.一般裝系統都有裝上. kdump 支持 N 種方式存儲內存數據,包括裸設備,文件系統,nfs,ssh.并且能設定 dump 前和 dump 后運行腳本以及執行其他動作.正所謂很好很強大. kdump 的 dump 機制是:預先生成一個 crashkernel,在內核 crash 的時候,激活這個 crashkernel,用這個 crashkernel

27、載入的小型系統 dump 處于 crash 狀態的內核. 實驗步驟: 這次我會配置 kdump 把內存數據 scp 到備份服務器上. 在 client 上: 安裝 kdump rootdhcp-0-157 # cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.2 (Tikanga rootdhcp-0-157 # cd /misc/cd/Server rootdhcp-0-157 Server# rpm -ivh busybox-1.2.0-4.el5.i386.rpm warning: busybox-1.2.

28、0-4.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186 Preparing. # 100% 1:busybox # 100% rootdhcp-0-157 Server# rpm -ivh kexec-tools-1.102pre-21.el5.i386.rpm warning: kexec-tools-1.102pre-21.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186 Preparing. # 100% 1:kexec-tools roo

29、tdhcp-0-157 Server# # 100% 配置 kdump rootdhcp-0-157 # vim /etc/kdump.conf net root10.66.0.84 對 kernel 開啟 kdump 支持 rootdhcp-0-157 # vim /boot/grub/grub.conf 在 kernel 選項上添加 crashkernel 參數. 參數格式是: crashkernel=nnKMGssKMG nn 表示要為 crashkernel 預留多少內存 ss 表示為 crashkernel 預留內存的起始位置 default=0 timeout=5 splashimage=(hd0,0/grub/splash.xpm.gz hiddenmenu title Red Hat Enterprise Linux Server (2.6.18-92.el5 root (hd0,0 kernel /vmlinuz-2.6.18-92.el5 ro root=LABEL=/ crashkernel=256M16M initrd /initrd-2.6.18-92.el5.img 重啟電腦使新參數生效. 然后啟用 kdu