Using the blkid Command getting UUID information disks

When failure of "scsi_id" command during ASM installation with udev rules, you can use "blkid" command to get UUID information of disks.

~]# blkid
/dev/vda1: UUID="7fa9c421-0054-4555-b0ca-b470a97a3d84" TYPE="ext4"
/dev/vda2: UUID="7IvYzk-TnnK-oPjf-ipdD-cofz-DXaJ-gPdgBW" TYPE="LVM2_member"
/dev/mapper/vg_kvm-lv_root: UUID="a07b967c-71a0-4925-ab02-aebcad2ae824" TYPE="ext4"
/dev/mapper/vg_kvm-lv_swap: UUID="d7ef54ca-9c41-4de4-ac1b-4193b0c1ddb6" TYPE="swap"

For instance, to display information about /dev/vda1, type:

~]# blkid /dev/vda1
/dev/vda1: UUID="7fa9c421-0054-4555-b0ca-b470a97a3d84" TYPE="ext4"

You can also use the above command with the -p and -o udev command line options to obtain more detailed information. Note that root privileges are required to run this command:

blkid -po udev device_name

For example:

~]# blkid -po udev /dev/vda1
ID_FS_UUID=7fa9c421-0054-4555-b0ca-b470a97a3d84
ID_FS_UUID_ENC=7fa9c421-0054-4555-b0ca-b470a97a3d84
ID_FS_VERSION=1.0
ID_FS_TYPE=ext4
ID_FS_USAGE=filesystem

Can SCAN IP be used for ftp of files ?

SCAN IP's can be used for ftp ,sftp and also ssh connection during rac cluster service already running . Because when cluster services are running scan ip's nic bonding to public network interface for example ;

In RAC Node1

oracle@testdbrac1:/oracle:>ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:50:56:B8:40:B0 

          inet addr:PUBLIC IP  Bcast:xxx.x.x.xxx  Mask:255.255.255.0

          inet6 addr: fe80::250:56ff:feb8:40b0/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:1006522 errors:0 dropped:0 overruns:0 frame:0

          TX packets:92530 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:99913091 (95.2 MiB)  TX bytes:32001574 (30.5 MiB)

eth0:2    Link encap:Ethernet  HWaddr 00:50:56:B8:40:B0 

          inet addr:SCAN IP_1  Bcast:xxx.x.x.xxx  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

In RAC Node 2

oracle@testdbrac2:/oracle:>ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:50:56:B8:40:B1 

          inet addr:PUBLIC IP  Bcast:xxx.x.x.xxx  Mask:255.255.255.0

          inet6 addr: fe80::250:56ff:feb8:40b1/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:1004162 errors:0 dropped:0 overruns:0 frame:0

          TX packets:69260 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:100817580 (96.1 MiB)  TX bytes:15328431 (14.6 MiB)

eth0:2    Link encap:Ethernet  HWaddr 00:50:56:B8:40:B1 

          inet addr:SCAN IP_2  Bcast:xxx.x.x.xxx  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

eth0:3    Link encap:Ethernet  HWaddr 00:50:56:B8:40:B1 

          inet addr:SCAN IP_3  Bcast: xxx.x.x.xxx  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

You can also check output command "ifconfig -a"  when rac services are not running. If you are planning for failover scenarios , it is reasonably.

Calculating optimal ulimit with RDA - Health Check

That's params from installation docs :

Open file descriptors	nofile	at least 1024	at least 65536
Number of processes available to a single user	nproc	at least 2047	at least 16384
Size of the stack segment of the process	stack	at least 10240 KB	at least 10240 KB, and at most 32768 KB

 We can confirm these parameters with RDA - Health Check utility. RDA - Health Check / Validation Engine Guide (Doc ID 250262.1)