Category Archives: Uncategorized

gmail encryption and limitations

Default Gmail encryption protects emails as much as possible. Google encrypts emails both when they’re stored (data at rest) and when they’re being sent (data in motion). Like most security-conscious providers, Google uses Transport Layer Security (TLS) to encrypt emails in transit. But TLS depends on both the sender’s and recipient’s email provider, so it won’t work in some situations.

 

Ampercent Encryption for Gmail

ORA 257 error


SELECT * FROM V$RECOVERY_FILE_DEST;

NAME            SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
--------------  ----------- ---------- ----------------- ---------------
/mydisk/rcva     5368709120 109240320             256000              28

SQL> show parameter db_recovery


NAME                                 TYPE        VALUE
-------------------------------- ----------- ------------------------------
db_recovery_file_dest                string      /opt/oracle/test01/flash_recovery_area
db_recovery_file_dest_size           big integer 10G

Command for changing db_recovery_file_dest

SQL> alter system set db_recovery_file_dest='/opt/oracle/test01/dbs/arch' scope=both;
System altered.

Making a Digitized Signature

Digitized Signature

CREATING A SIGNATURE PNG FILE

  1. Sign your name on a blank sheet of printer paper. Paper quality and type of pen doesn’t really matter, just make sure your signature is straight and not on an angle.
  2. Scan the paper to PDF. With Acrobat Pro DC select File > Create > From Scanner > Color Document.
  3. Press the “Print Screen” button on your keyboard.
  4. Open Microsoft Paint.
  5. Press Ctrl + v on your keyboard to paste the screen shot from step 3.
  6. Click the select tool in Paint.
  7. Drag a rectangle around the signature staying as close as possible to the outer edges of the signature.
  8. Select “Crop”, and the image should be resized to the size of the rectangle in the previous step.
  9. Select “Save As > Png Picture”, name the file “My Signature”, and save it to your desktop.

MAKING THE BACKGROUND TRANSPARENT

  1. Find a free online image converter by Googling “Convert Image To Transparent Background Online” and use the image converter to make the background transparent. When I Googled that, number one was Lunapic (http://www125.lunapic.com/editor/?action=transparent).  The next steps use this particular tool to convert the image to one with a transparent background.
  2. Click “Choose File” and upload the .png file from step 9.
  3. From the Lunapic toolbar, select Edit > Make Transparent.
  4. Click a white part of the image.
  5. Click “Save” and save the new transparent signature to your desktop.

     

    CREATING THE STAMP

    1. Select the stamp menu on the Acrobat Pro comments toolbar menu and select Stamps > Custom Stamps > Create.
    2. Click the “Browse” button in the dialog window, change the file type dropdown to “.png”, browse for and select the transparent signature file from step 14.
    3. Click “Open”.
    4. Click “OK”.
    5. Name the stamp category (something like “My Signatures” or you can select the pre-existing “Sign Here” from the dropdown menu).
    6. Name the stamp.
    7. Click “OK”. You will most likely have to create this stamp twice due to sizing issues.
    8. Open a blank PDF. You can create one by opening the javascript console (ctrl + j) and running the following script:  app.newDoc();  You run the script by placing the cursor anywhere on the line containing the script and pressing ctrl + Enter on your keyboard.
    9. Go back to the stamp menu and select the stamp you just created and stamp the document. You’ll notice that the signature is probably much too large.  Resize it by dragging one of the corners inward.
    10. When you have the signature stamp to the correct size, save the PDF to your desktop.
    11. Repeat steps 15 through 21 EXCEPT, use the PDF file created in the previous step as the file from which you will create the stamp. This will create the stamp the correct size so you don’t have to resize it every time you apply it.

Lunapic Editor

dbca troubleshooting fun

Looking at Oracle 18c
After getting the database code trees installed I went on to the dbca creation

I saw there was a log directory for dbca creations

/u01/app/oracle/cfgtoollogs/dbca

The logs are listed in groups of (2)
starting with trace and silent

many failed attempts, but this is a good place to start to get the problems solved.
Currently we have a situation that the create failed due to ASM checks

Not sure why this is occurring as the ASM disks are up and available

GRID Troubleshooting

(Doc ID 1050908.1) Troubleshoot Grid Infrastructure Startup Issues
(Doc ID 2291661.1) SRDC – Grid Infrastructure / Clusterware Administration and Management
(Doc ID 1513912.1) TFA Collector – TFA with Database Support Tools Bundle
(Doc ID 1053147.1) For detailed Grid Infrastructure clusterware startup sequence, please refer to note
[ Doc ID 1929376.1 ] “My Oracle Support – Automated Troubleshooting”

crsctl commands

1. STOP & START CRS: ( run from root user)


$GRID_HOME/bin/crsctl stop crs
 
$GRID_HOME/bin/crsctl start crs


$GRID_HOME/bin/cemutlo -n



$GRID_HOME/bin/crsctl stat res -t
 
$GRID_HOME/bin/crsctl check crs
 
$GRID_HOME/bin/crsctl check cssd
 
$GRID_HOME/bin/crsctl check crsd
 
$GRID_HOME/bin/crsctl check evmd
 

RAC Networking Considerations

Networking Considerations

For the private network 10 Gigabit Ethernet is highly recommended, the minimum requirement is 1 Gigabit Ethernet.

Underscores are not be used in a host or domain name according to RFC952 – DoD Internet host table specification. The same applies for Net, Host, Gateway, or Domain name.

The VIPs and SCAN VIPs must be on the same subnet as the public interface. For additional information see the Understanding SCAN VIP white paper.

The default gateway must be on the same subnet as the VIPs (including SCAN VIPs) to prevent VIP start/stop/failover issues. With 11gR2 this is detected and reported by the OUI, if the check is ignored this will result in the failure to start the VIPs resulting in failure of the installation itself.

It is recommended that the SCAN name (11gR2 and above) resolve via DNS to a minimum of 3 IP addresses round-robin regardless of the size of the cluster. For additional information see the Understanding SCAN VIP white paper.

To avoid name resolution issues, ensure that the HOSTS files and DNS are furnished with both VIP and Public host names. SCAN must NOT be in the HOSTS file due to the fact that the HOSTS file
is only able to represent a 1:1 host to IP mapping.

The network interfaces must have the same name on all nodes (e.g eth1 -> eth1 in support of the VIP and eth2 -> eth2 in support of the private interconnect).
Network Interface Card (NIC) names must not contain ” . ”

Jumbo Frames for the private interconnect is a recommended best practice for enhanced performance of cache fusion operations. Reference: Document 341788.1

Use non-routable network addresses for private interconnect; Class A: 10.0.0.0 to 10.255.255.255, Class B: 172.16.0.0 to 172.31.255.255, Class C: 192.168.0.0 to 192.168.255.255. Refer to RFC1918 and Document 338924.1 for additional information.
Make sure network interfaces are configured correctly in terms of speed, duplex, etc. Various tools exist to monitor and test network: ethtool, iperf, netperf, spray and tcp. See Document 563566.1.

To avoid the public network or the private interconnect network from being a single point of failure, Oracle highly recommends configuring a redundant set of public network interface cards (NIC’s) and private interconnect NIC’s on each cluster node.. Document 787420.1. Starting with 11.2.0.2 Oracle Grid Infrastructure can provide redundancy and load balancing for the private interconnect (NOT the public network), this is the preferred method of NIC redundancy for full 11.2.0.2 stacks (11.2.0.2 Database must be used). More information can be found in Document 1210883.1.

NOTE: If using the 11.2.0.2 Redundant Interconnect/HAIP feature – At present it is REQUIRED that all interconnect interfaces be placed on separate subnets. If the interfaces are all on the same subnet and the cable is pulled from the first NIC in the routing table a rebootless-restart or node reboot will occur. See Document 1481481.1 for a technical description of this requirement.

For more predictable hardware discovery, place hba and nic cards in the same corresponding slot on each server in the Grid.

The use of a switch (or redundant switches) is required for the private network (crossover cables are NOT supported).

Dedicated redundant switches are highly recommended for the private interconnect due to the fact that deploying the private interconnect on a switch (even when using a VLAN) may expose the interconnect links to congestion and instability in the larger IP network topology. If deploying the interconnect on a VLAN, there should be a 1:1 mapping of VLAN to non-routable subnet and the VLAN should not span multiple VLANs (tagged) or multiple switches. Deployment concerns in this environment include Spanning Tree loops when the larger IP network topology changes, Asymmetric routing that may cause packet flooding, and lack of fine grained monitoring of the VLAN/port. Reference Bug 9761210.

If deploying the cluster interconnect on a VLAN, review the considerations in the Oracle RAC and Clusterware Interconnect Virtual Local Area Networks (VLANs) white paper.

Consider using Infiniband on the interconnect for workloads that have high volume requirements. Infiniband can also improve performance by lowering latency. When Infiniband is in place the RDS protocol can be used to further reduce latency. See Document 751343.1 for additional details.

In 12.1.0.1 IPv6 is supported for the Public Network, IPv4 must be used for the Private Network. Starting with 12.2.0.1 IPv6 is fully supported for both the public and private interfaces. Please see the Oracle Database IPv6 State of Direction white paper for details.
For version Grid Infrastructure 11.2.0.2 multicast traffic must be allowed on the private network for the 230.0.1.0 subnet. Patch: 9974223 (Included in GI PSU 11.2.0.2.1 and above) for Oracle Grid Infrastructure 11.2.0.2 enables multicasting on the 224.0.0.251 multicast address on the private network. Multicast must be allowed on the private network for one of these 2 addresses (assuming the patch has been applied). Additional information as well as a program to test multicast functionality is provided in Document 1212703.1.