Thank you for your reply, Mike. Now my iscsi disk performance can be around 300MB/s in 4M sequence write(TCMU+LIO) It increase from 20MB/s to 300MB/s, after I can change max_data_area_mb from 8 to 256 && hw_max_sectors from 128 to 8192. To my cluster, after a lot of tests I found that I should keep "max_data_area_mb>128 && hw_max_sectors>=4096" in order to get a good performance. Does my setting can cause some side effects? Are there any other parameters can improve the performance quite obvious? Why the default value of max_data_area_mb and hw_max_sectors is so small, and bad performance? Could you talk something about this? At least, max_data_area_mb>128 && hw_max_sectors>=4096, I can get a better performance seems to be acceptable. If my settings can give other users some help, I will be happy.
在 2018年9月12日星期三 UTC+8上午12:39:16，Mike Christie写道： > > On 09/11/2018 11:30 AM, Mike Christie wrote: > > Hey, > > > > Cc [email protected] <javascript:>, or I will not see these messages > until I check > > the list maybe once a week. > > > > On 09/05/2018 10:36 PM, [email protected] <javascript:> wrote: > >> What lio fabric driver are you using? iSCSI? What kernel > version > >> and > >> what version of tcmu-runner? > >> > >> io fabric driver : iscsi > >> > >> iscsid version: 2.0-873 > >> > >> OS version: CentOS Linux release 7.5.1804 (Core) > >> > >> kernel version: 3.10.0-862.el7.x86_64 > >> > >> tcmu-runner version: 1.4.0-rc1 > >> > >> > > There is also a perf bug in that initiator if the node.session.cmds_max > is greater than the LIO default_cmdsn_depth and your IO test tries to > send cmds > node.session.cmds_max. > I have known the bug before, because I had google a lot. It increase from 320MB/s to 340MB/s (4M seq write), seems like a stable promotion. Settings Before: 320MB/s node.session.cmds_max = 2048 default_cmdsn_depth = 64 Settings After: 340MB/s node.session.cmds_max = 64 default_cmdsn_depth = 64 So set the node.session.cmds_max and default_cmdsn_depth to the same > value. You can set the default_cmdsn_depth in saveconfig.json, and set > cmds_max in the iscsiadm node db (after you set it make sure you logout > and login the session again). > Now I set set the node.session.cmds_max and default_cmdsn_depth both to be 64. Thank you very much! -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
