Here’s how you can connect and communicate with external storage on RHEL
We will be using multipath daemon
To list all the LUNs attached to host
multipath -ll
To reload multipath
service multipathd reload
To list and check status of the FC cards
systool -c fc_host -v
To rescan for new LUNs
/usr/bin/rescan-scsi-bus.sh
OR
echo “1” > /sys/class/fc_host/host#/issue_lip
echo “1” > /sys/class/fc_host/host#/issue_lip
Here’s guide on how to work with logical volume management on RHEL
To see & rescan physical volumes
pvs
pvscan
To see & rescan volume group
vgs
vgscan
To see & rescan logical volumes
lvs
lvscan
Here’s guide on how to increase the logical volume
lvresize -r -L + ##G /dev/myvg/mylv (extend by gigabyte)
lvresize -r -l +#### /dev/myvg/mylv (extend by bytes)
lvresize -r -l +100%FREE /dev/myvg/mylv (extend by percentage)
or
lvextend -L #G /dev/myvg/mylv (set to specific size by gigabyte)
lvextend -L +#G /dev/myvg/mylv (extend by bytes)
lvextend -l +100%FREE /dev/myvg/mylv (extend by percentage)
*lvextend will not show any free space after the execution.
*try to run the command “resize2fs /dev/mapper/logicalVolumePath/” and check df -Ph to verify that they have free space afterwards
Here’s guide on how to reduce the logical volume
1. Shutdown all applications/databases which are hosted in the logical volume management
2. Complete the backup
3. Unmount the file system
4. Hashout the file system entry in /etc/fstab
5. It’s only applicable for ext2/ext3/ext4
6. Check for any errors (e2fsck -f “logical_volume_path”)
ex: e2fsck -f /dev/mapper/rhel_vg-lv0
7. Reduce the file system (resize2fs “logical_volume_path” “want_to_become_size”)
ex: resize2fs /dev/mapper/rhel_vg-lv0 1G
8. Reduce the logical volume size (lvreduce -L “want_to_become_size” “logical_volume_path”)
ex: lvreduce -L 1G /dev/mapper/rhel_vg-lv0
9. Uncomment on /etc/fstab
10. Mount the file system
Create new LUN on Unity by Dell-EMC
Login to GUI
Go to navigation menu on left Storage > Block
Click the “+” sign to create
-name it with hostname, date and purpose for easy identification
-provide description to identify
-put tiering policy: “Start High Then Auto-Tier” default is recommended
-uncheck the thin provisioning option
-size as requested
-thin option (checked means increase in disk usage as data is written, uncheck means immediate increase)
-no limit on I/O
Provide access to hosts
-set up the hosts connection by clicking “+” sign
Setup snapshot schedule as needed
Setup replication as needed
Create new LUN on Pure Storage
Login to the GUI
Create a new voume by going to Storage > Volumes
Click + to create new LUN
-name it with hostname, date and purpose for easy of identification
-give the size on “Provisioned Size”
-click “Create”
Connect the new LUN to host on Storage > Hosts
-search the hosts and click into it
-if you are not sure, you can look into the hostname on Health > Connections
-if you are not sure, you can look into the host and double check WWN of host’s FC card ports
-click into the 3 dots on to right upper corner
-click “Connect”
-search the LUN by LUN name given and check
-click “Connect”
-click the new LUN created and share the Serial number for sysadmin to identify
Tips & Tricks for Data Domain by Dell-EMC
You can utilize by GUI on web, or ssh into the data domain
Here’s example of data domain commands
To shows current alerts
alerts show current
To unfail the new replaced disk after replacing faulty disk (does not come back online automatically)
disk unfail disk_position (ex: 1.1)
Show the state for disks
disk show state
Shows the properties of disk hardware
disk show hardware
Clean up filesystem
filesys clean start
Check filesystem status
filesys status
Tips & Tricks on VNX storage by Dell-EMC
default ID and PW
ID: nasadmin
PW: nasadmin
ID: root
PW: nasadmin
To check domain list
/nas/sbin/navicli -h spa domain -list
To check failover/failback status
/nasmcd/sbin/getreason
To utilize navisseccli
/nas/sbin/naviseccli -h SPA -user sysadmin -password <password> -scope 0 domain -messner -add -system <CS_IP>
To generate CA certificate for GUI
/nas/sbin/nas_ca_certificate -generate
To extend NFS on VNX
Storage > Storage > Storage Configuration > File Systems
click on appropriate file system
click “Extend” and provide the extend size
click “OK” or “Apply”
Cleaning the Control Station on VNX
ssh into control station (IP noted on storage manual)
Check to see if there’s any stale tasks
cd /nas/tasks (only primary control station has this filesystem)
ls | wc -l
*should be normal to see single to double digits…
Remove any stale tasks
rm -rf *_status
rm -rf *_pipe
check back the stale task status by another command of
ls | wc -l
to see the failover/failback status
/nasmcd/sbin/getreason
10 – slot_0 primary control station (slot_0 should be always primary, if else, login to slot_1 primary and reboot)
0 – slot_1 reset
5 – slot_2 contacted
5 – slot_3 contacted
bring back to the primary node (as recommended)
login to slot_1 primary by command
su – nasadmin
reboot
Do not reboot from both primary and secondary control station at once! it will cause serious damage!
*wait for full boot up on each side and check status by getreason commands
How to disable or enable write cache on Unity
SSH into Primary SP
-use OS account “service” with password the same as admin account
-use commands like below to enable or disable
*you only need to run it once and it’ll be applied to both nodes!
svc_cache –get
shows status
3 means enabled
7 means transitioning
8 means disabled
svc_cache –force-enableCacheOperations
force enable cache
Here’s the procedure for maintenance
1) disable write cache option (only need to do once on SP A or B)
2) put Unity SP A or B on service mode
3) on-site engineer will replace parts
4) put Unity SP A or B out of service mode
5) enable write cache option
How to work on Brocade SAN Switch
To see what’s connected on the switch
switchshow
You can do and press forward slash (/) to search the specific WWN of your newly connected server
switchshow | more
To see what alias are set up on the switch
alishow
To see what zones are set up on the switch
zoneshow
Now we will create alias between WWN to Hostname
alicreate “hostName”,”WWN”
Once we’ve added the alias, we can set up the zone between new server alias to storage
zonecreate “zoneName”,”hostName;storageName”
zonecreate “hostName_fabricConfigName_storageName”,”hostName;storageName“
Once the zone is configured, we need to add and enable the new configuration as below
cfgadd “configName”,”zoneName”
cfgsave
cfgenable “configName“
Tips & Tricks on how to use IBM TS4300 Tape Library
Here’s the specification and details on IBM
Cleaning the tapes inside the tape library
– login to TS4300 GUI
– input the credentials
– click on tab “Drives” on left menu
– click on dropdown menu “Actions”
– select “Clean Drive”
– select the cleaning tape on left, and destination drive on right
– click “Move” and allow it to clean the drive