Release Notes

Connectivity considerations
15 Dell EMC PowerVault ME4 Series and Linux | 3924-BP-L
4. Verify the host has established the iSCSI sessions to all the ME4 Series iSCSI ports. The following
command should display a session for each ME4 Series iSCSI port. In this example, 10.10.61.12
corresponds to A2, 10.20.61.12 corresponds to B2, 10.10.61.13 corresponds to A3, and 10.20.61.13
corresponds to B3.
# iscsiadm -m node
10.10.61.12:3260,5 iqn.1988-11.com.dell:01.array.bc305bf03b17
10.20.61.12:3260,6 iqn.1988-11.com.dell:01.array.bc305bf03b17
10.20.61.13:3260,7 iqn.1988-11.com.dell:01.array.bc305bf03b17
10.10.61.13:3260,8 iqn.1988-11.com.dell:01.array.bc305bf03b17
5. Identify the host iSCSI initiator IQN. The IQN information is required to create the host object in ME
Storage Manager.
# cat /etc/iscsi/initiatorname.iscsi
2.2.2.3 Host TCP settings and other tuning considerations
Kernel parameters that can be tuned for performance are found in the /proc/sys/net/core and
/proc/sys/net/ipv4 kernel parameters. Once optimal values are determined, permanently set these in the
/etc/sysctl.conf file. Like most other modern operating system platforms, Linux can efficiently auto-tune TCP
buffers. However, by default, some settings such as buffer size are conservatively low. Experimenting with the
following kernel parameters can lead to improved network performance, and subsequently improve iSCSI
performance.
To set these parameters permanently, enter them in the /etc/sysctl.conf file and reboot the servers.
An example of TCP settings for 10 GB network
Parameter
Value
Description
net.core.rmem_max
134217728
Maximum receive buffer size used by
each TCP socket
net.core.wmem_max
134217728
Maximum send buffer size used by
each TCP socket
net.ipv4.tcp_rmem
4096 87380 134217728
Auto-tune TCP buffer limits: min,
default, and max size of the receive
buffer used by each TCP socket
net.ipv4.tcp_wmem
4096 65536 134217728
Auto-tune TCP buffer limits: min,
default, and max size of the send buffer
used by each TCP socket
net.core.netdev_max_backlog
300000
Maximum number of incoming
connections backlog queue
net.ipv4.tcp_moderate_rcvbuf
1
Auto-tune the receiver buffer size
net.bridge.bridge-nf-call-iptables
0
netfilter
net.bridge.bridge-nf-call-arptables
0
netfilter
net.bridge.bridge-nf-call-ip6tables
0
netfilter