Note that librados can access data from all nodes in the cluster while iSCSI will funnel the data through whatever node or proxy is hosting the iSCSI target. What does your overall network and storage layout look like? Number of systems, number and type of disks, how are Ceph journals set up, etc?
From: open-iscsi@googlegroups.com [mailto:open-iscsi@googlegroups.com] On Behalf Of Wyllys Ingersoll Sent: Tuesday, August 26, 2014 2:05 PM To: open-iscsi@googlegroups.com Subject: Re: iscsi over RBD performance tips? iscsi performance to a RAM disk iscsi target using the same fio parameters, yields a 1GB/second throughput for both read and write operations, compared to about 400(r)/400(w) MB/second using an RBD based backend over a 10GB link. My fio job file looks like this (change 'randread' to 'randwrite' for the write test and modify the filename device to switch between the ramdisk and rbd). [default] rw=randread size=10g bs=1m ioengine=libaio direct=1 numjobs=1 filename=/dev/sdb runtime=600 write_bw_log=iscsiread iodepth=256 iodepth_batch=256 -- 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 open-iscsi+unsubscr...@googlegroups.com<mailto:open-iscsi+unsubscr...@googlegroups.com>. To post to this group, send email to open-iscsi@googlegroups.com<mailto:open-iscsi@googlegroups.com>. Visit this group at http://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 open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
