Using ROBOCOPY to move a large amount of files from one network destination to other

robocopy source destination /e /zb /dcopy:t /copyall /r:1 /w:1 /v /tee /efsraw /j /log:c:\temp\robocopy.log

Source :: \\Network location.
Destination :: \\Network location.
/e :: copy sub-directories including empty ones.
/zb :: Copies files in restartable mode. If file access is denied, switches to backup mode.
dcopy:t :: Copy time stamps.
/copyall :: Specifies which file properties to copy.
The valid values for this option are:
    D - Data
    A - Attributes
    T - Time stamps
    S - NTFS access control list (ACL)
    O - Owner information
    U - Auditing information
/r:1 :: Specifies the number of retries on failed copies.
/w:1 :: Specifies the wait time between retries, in seconds.
/v :: Produces verbose output, and shows all skipped files.
/tee :: Writes the status output to the console window, and to the log file.
/efsraw :: Copies all encrypted files in EFS RAW mode.
/j :: Copies using unbuffered I/O (recommended for large files).


Copy only the changed files after the initial copy has been completed for live share.

robocopy source destination  /XO

Burn ISO file to USB under Mac OS command line

Use following command to find the connected USB device.

system_profiler SPUSBDataType | grep -iC 1 "BSD"

i :: ignore case
C 1 :: print 1 lines before and after the matching string
BSD :: Search string. In this example, BSD is the search string.

Unmount the USB drive using following command. If the USB has multiple partition, need to unmount all the listed disks from previous command.

diskutil unmountdisk /dev/disk2

Use following command to write ISO file on USB 

sudo dd if=ubuntu-18.04.3-live-server-amd64.iso of=/dev/disk2 bs=1M status=progress

dd:: Start dd command to write DVD/CD iso image.
if=/*iso:: Path to input file.
of=/dev/disk2:: Path to destination USB disk/stick.
bs=1M:: read and write up to BYTES at a time. In this example, 1M at a time.
status=progress:: Display progress.

Faulty HBA, SFP in ESXI 6.0 host

I was facing a huge issue with one of ESXI host. During backup, I was losing network connections to VMs (avg 5 - 10 mins) and sometimes VMs ended with disk consolidation issue. vMotion failed intermittently too. Initially, I thought it was a network card issue, eventually I ruled out network card failure. Then I started to check storage connectivity and HBA performance; looking for error and fail messages in vmkernel log file.

Login to ESXI host using SSH. Run following command to find active HBA.

esxcli storage san fc list  

Adapter: vmhba2
Port ID: 011100
Node Name: 20:00:00:05:1e:fa:f4:82
Port Name: 10:00:00:05:1e:fa:f4:82
Speed: 8 Gbps
Port Type: NPort
Port State: ONLINE

Adapter: vmhba4
Port ID: 011100
Node Name: 20:00:00:05:1e:fa:f8:2b
Port Name: 10:00:00:05:1e:fa:f8:2b
Speed: 8 Gbps
Port Type: NPort
Port State: ONLINE


Now check vmkernel log using following command:

grep -i 'failed' /var/log/vmkernel.log | less

If you see errors like following, then consult following KB to understand what the error means. You will be able to find details using the code highlighted as red.


https://kb.vmware.com/s/article/1029039

2020-10-05T06:23:15.484Z cpu1:1587135)NMP: nmp_ThrottleLogForDevice:3302: Cmd 0x2a (0x43b5c1643380, 1782124) to dev "naa.60060e801054bf60056fd48600000009"

on path "vmhba2:C0:T3:L29" Failed: H:0x7 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0. Act:EVAL

In my case, it means outdated HBA firmware. Usually, it is hardware failure not a firmware issue. I would suggest to replace the SFP before replacing the HBA card. If the issue is not resolved, you need to replace the HBA card.

If you replace the HBA card, you need to reconfigure fiber switch and SAN to connect with existing LUN.

Installing Ubuntu Server on a Raspberry Pi 2, 3 or 4

It is very easy now to install Ubuntu Server on Raspberry Pi. THE following URL has detailed instructions.

https://ubuntu.com/tutorials/how-to-install-ubuntu-on-your-raspberry-pi#1-overview

In step 3, you will have issue if you use Windows 10 machine instead of Linux machine. You cannot read the file system to edit "network-config" file. To resolve the issue - boot your Raspberry Pi, log in using default user ID and password (ubuntu/ubuntu). Change the default password after changing the the config.

Edit the following file using 'nano'.

sudo nano /etc/netplan/50-cloud-init.yaml

Add WiFi details in the yaml file, save and restart. Make sure to remove '()'.


network:
    ethernets:
        eth0:
            dhcp4: true
            optional: true
    version: 2
    wifis:
      wlan0:
           dhcp4: true
           optional: true
           access-points:
              (name of the home SSID):
               password: (WPA2 password)

You are ready for step 4.