On 09/03/2018 02:31 AM, [email protected] wrote: > Hello Mike, > > I am very appreciate for your instruction. > Now I can set hw_max_sectors through targcli when i create the device. > I set it to 8192 same as raw rbd device. > The performance improve a little, 4M seq write increase from 24MB/s to > 40MB/s.(hw_max_sectors 64->8192, it is a /backstore/user:rbd/disk_xxx > device) > But it is far away from block device, if I usr /backstore/block 4M seq > write it will be 500MB/s, performance is still a big problem.(first I > should map a rbd device , then export it by targetcli) > > The performance difference between /backstore/user:rbd/ and > /backstore/block is so big, is it normal?
backstore/user will be lower than block, but I do not think it would a difference like you are seeing. What lio fabric driver are you using? iSCSI? What kernel version and what version of tcmu-runner? > Could you give me some suggestions about improving the performance of > /backstore/user:rbd/ device. > > Thanks very much! > > 在 2018年9月3日星期一 UTC+8上午10:31:48，[email protected]写道： > > Hello Mike, > > Thank you for your informative response. > > > 在 2018年8月28日星期二 UTC+8上午8:49:46，Mike Christie写道： > > On 08/21/2018 08:52 PM, [email protected] wrote: > > Hi folks, > > > > I am newbie to open-iscsi. > > My case is I export ceph rbd by open-iscsi. > > > > I found the max_sectors_kb is 64, the value is so small, and > 4M sequence > > write is only about 10MB/s. > > I can not increase max_sectors_kb, if I do it will return > "bash: echo: > > write error: Invalid argument"(But I can change the value to a > small one > > < 64, max_hw_sectors_kb is 32767) > > > > In new version of the linux kernel the initiator will use the > optimal > value reported by the target and then uses the max reported as > the limit > that the user can set. It sounds like you are using rbd/ceph with > tcmu-runner which has a default limits of 64K. > > Yes, I am using tcmu-runner and gwcli. > > > If you are using targetcli/lio directly then you can set > hw_max_sectors > through targcli when you create the device or in the > saveconfig.json file. > > If you are using the ceph-iscsi tools then I am actually working > on a > gwcli command to configure this right now. > > Yes, I am using ceph-iscsi tools.How can I change the limit by > ceph-iscsi tools? > > Thanks. > > -- > 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] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/open-iscsi. > For more options, visit https://groups.google.com/d/optout. -- 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.
