How to Extend LVM Swap Partition

How to Extend LVM Swap 

1. Turn off swap 
   1.  swapoff /dev/mapper/vg_spacewalk-lv_swap  
2. Resize Swap LVM Partition 
   1. [root@spacewalk /]# lvresize -L 5G /dev/mapper/vg_spacewalk-lv_swap   Extending logical volume lv_swap to 5.00 GiB   Logical volume lv_swap successfully resized  
3. Make swap again 
   1. [root@spacewalk /]# mkswap /dev/mapper/vg_spacewalk-lv_swap mkswap: /dev/mapper/vg_spacewalk-lv_swap: warning: don't erase bootbits sectors         on whole disk. Use -f to force. Setting up swapspace version 1, size = 5242876 KiB no label, UUID=b5b26e00-dfb5-4767-bfac-985d125c8331  
4. Turn swap back on 
   1. [root@spacewalk /]# swapon -v /dev/vg_spacewalk/lv_swap swapon on /dev/vg_spacewalk/lv_swap swapon: /dev/mapper/vg_spacewalk-lv_swap: found swap signature: version 1, page-size 4, same byte order swapon: /dev/mapper/vg_spacewalk-lv_swap: pagesize=4096, swapsize=5368709120, devsize=5368709120  
5. Check swap size 
   1. [root@spacewalk /]# swapon -s Filename                                Type            Size    Used    Priority /dev/dm-1                               partition       5242872 0       -1  
   2. [root@spacewalk /]# free -m              total       used       free     shared    buffers     cached Mem:          1877       1775        101          0         25        285 -/+ buffers/cache:       1464        413 Swap:         5119          0       5119

How to Create iSCSI Server and Target

Reference Guide 

• http://gurkulindia.com/main/2013/04/rhel-6-iscsi-administration-series-configuring-iscsi-server-and-client/  
• http://www.packetgeek.net/2012/10/rhce-series-http/ 

Create ISCI Server 

1. yum install scsi-target-utils.x86_64' 
2. Turn on tgtd 
   1. # chkconfig tgtd on 
   2. # service tgtd start Starting SCSI target daemon:                               [  OK  ]  
3. Use tgtadm  to configure target 
   1. tgtadm -help  

4. Check if any existing targets exist 
   1. tgtadm --lld iscsi --mode target --op show 
   
   
5. Configure the first target ID as 101 
   1. # tgtadm --lld iscsi --mode target --op new --tid 101 --targetname iqn.server1.example.com:target1  
6. Verify the target  
   1. # tgtadm --lld iscsi --mode target --op show   
7. Create 1G logical volume for testing (of course in the real world you'd use a storage volume or lun) 
   1. ]# lvcreate -L 1G -n lv_iscsi vg_server1  
8. Attach LUN to the ISCSI Target (decide which disk to use - example in step above) 
   1. ]# tgtadm --lld iscsi --mode logicalunit --op new --tid 101 --lun 1 --backing-store /dev/mapper/vg_server1-lv_iscsi  
   2.  repeat of you want two 'luns'  
9. Verify new lun 
   1. # tgtadm --lld iscsi --mode target --op show 
   
   
10. Share to specific Network or Client 
    1. # tgtadm --lld iscsi --mode target --op bind --tid 101 --initiator-address 192.168.0.0/24 
    
    
11. Configure authentication to the target 
    1. # tgtadm --lld iscsi --mode account --op new --user iclient --password password  
12. Attach user to the 101 target 
    1. # tgtadm --lld iscsi --mode account --op bind --tid 101 --user iclient 
    
    
13. Verify User was attached to target 101 
    1. # tgtadm --lld iscsi --mode account --op show Account list:     iclient 
    2. # tgtadm --lld iscsi --mode target --op show 
    
    
14. Backup the original configuration 
    1. # cp /etc/tgt/targets.conf /etc/tgt/targets.orig  
15. Create configuration file from the dump command 
    1. # tgt-admin --dump default-driver iscsi  <target iqn.server1.com.example.target1>         backing-store /dev/mapper/vg_server1-lv_iscsi         incominguser iclient PLEASE_CORRECT_THE_PASSWORD         initiator-address 192.168.0.0/24 </target>   
16. Copy or 'echo' the output of above dump command into targets.conf file to allow for persitance  
    1. tgt-admin --dump >> /etc/tgt/targets.conf 
    2. remove or comment out the duplicate 'default-driver iscsi'  
17. Verify configuration after restart 
    1. # service tgtd restart  
18. Check what ports are in use 
    1. # netstat -pantl | grep tgt  
19. Add firewall rules (if using iptables) 

Client Configuration 

1. Install client tools if not installed 
   1. # yum install iscsi-initiator-utils 

2. Configure for restart  
   1. # service iscsid restart Stopping iscsid: Starting iscsid:                                           [  OK  ] [root@tester1 ~]# service iscsid force-start Starting iscsid: [root@tester1 ~]# chkconfig --list iscsid iscsid          0:off   1:off   2:off   3:on    4:on    5:on    6:off 
   
   
3. # iscsiadm -m discovery -t st -p 192.168.56.102 
   1. # dmesg | tail  
4. # iscsiadm -m node T iqn.2013-10.com.example.server1:target1 -p 192.168.56.102:3260,1 -l 

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Firs not down question points correctly 

 Exam use FQDN  DON’T FORGET TO LOGOUT AT  END ITS VERY IMP  

  

yum install iscsi* -y 

man iscsiadm , go to end of page it will be given 

iscsiadm --mode discoverydb --type sendtargets --portal 192.168.0.254 --discover [ change to server ip ] 

192.168.0.254:3260,1 iqn.2010-09.com.example:rdisks.server24 

now copy IQN  "iqn.2010-09.com.example:rdisks.server24" IP 192.168.0.254 , leave port as it is. 

Copy Login line , replace iqn and ip of server 

iscsiadm --mode node --targetname iqn.2010-09.com.example:rdisks.server24 --portal 192.168.0.254:3260 --login 

now fdisk -l 

check the mounted /dev/sda 

create partition of given size 

now mkfs.xt4 /dev/sda1 

blkid /dev/sda1 and copy uuid [ UUID="f48afc51-d621-4046-932e-b6084d2286be" ] 

vim /etc/fstab 

   [ Device Name]                                                              [Where to store] file-type   defaults 

UUID="f48afc51-d621-4046-932e-b6084d2286be"     /mnt/storage       ext4      _netdev 0 0 

umount -a 

mount  -a 

go to mount /mnt/storage 

download file and chmod 644 to file