The server has been running iSCSI service for the diskless client, and I have noticed that the connection of server's gateway(internet connection or a fake gateway) made iSCSI performance worse.
Is there anybody who has experienced this OR who could give any suggestion for debugging?
FYI: the results of 'fio' test are OK even if the default gateway is connected. So I think that the issues are in iSCSI.
Environment:
CentOS 7.7.1908 / Kernel 3.10.0-1062.18.1.el7.x86_64
ZFS version zfs-0.8.3-1 / zfs-kmod-0.8.3-1
targetcli version 2.1.fb46
Server NIC: Intel 4 ports 1Gbps, 4 ports trunk
Switch: 1Gbps 48 ports, 4 ports trunk
zpool iostat when server's default gateway is connected. (attached cable)
capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
zp1 177G 751G 470 85 56.8M 8.82M
zp1 177G 751G 684 34 83.4M 3.12M
zp1 177G 751G 414 979 49.6M 90.7M
zpool iostat when server's default gateway is not connected. (detached cable)
capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
zp1 176G 752G 2.19K 445 276M 3.45M
zp1 176G 752G 2.50K 428 314M 4.21M
zp1 176G 752G 1.92K 3 243M 60.0K