To check read speed you can use the following command
hdparm -Tt /dev/sda1
Timing cached reads: 25292 MB in 2.00 seconds = 12664.26 MB/sec
Timing buffered disk reads: 432 MB in 3.01 seconds = 143.56 MB/sec
Here 12664.26 MB/sec & 143.56 MB/sec are the read speeds.
DD command will give the write speed of hard drives
dd if=/dev/zero of=/tmp/output bs=1024 count=4096k conv=fdatasync; rm -f /tmp/output
4194304+0 records in
4194304+0 records out
4294967296 bytes (4.3 GB) copied, 165.193 s, 26.0 MB/s
Here 26.0 MB/s is the write speed.
Hope this helps!
1. Need to generate a local public key file from client machine
# ssh-keygen -t dsa
( from client machine)
2. Copy the file to the server
# scp ~/.ssh/id_dsa.pub firstname.lastname@example.org:/home/user
3. Login to the server and add the key to authorized_keys file
# cat id_dsa.pub >> .ssh/authorized_keys
4. Delete the original file you copied
# rm -r id_dsa.pub
All done, now just ssh to the server. It will login without the password.
Note : Passwordless authentication is a big security risk.
Running multiple websites on a single server can be done with Apache Virtualhosting.
1. Change the directory to sites-available
2. Create a new file called example.conf
3. Copy and paste this entire code in example.conf Continue reading “Apache Virtualhost on Ubuntu”
1. Create a swap file.
dd if=/dev/zero of=/mnt/swapfile bs=1024 count=4096k
This will create a 4GB of swap file which can be used for 8GB server.
2. Change the file to swap partition.
3. Enable swap
4. Verify swap partition.
NOTE: All the above operations need to be done with a sudo user or by root.
All the operations need to be done as a Zimbra user.
1. Point a domain to an SMTP server
zmprov ms mail.example.com zimbraMtaRelayHost smtp.sendgrid.net
2. Add SMTP authentication for smtp relay server
echo smtp.sendgrid.net username:password > /opt/zimbra/conf/relay_password
3. Export it to postfix
4. Check the credentials are saved properly
postmap -q smtp.sendgrid.net /opt/zimbra/conf/relay_password
5. Setup SASL to use smtp relay authentication Continue reading “Zimbra & Sendgrid SMTP Setup”