<div dir="ltr"><div><div>Hi, </div>i have a problem, i used many ISCSI zvol (for each vm), network traffic is 2MB/s between kvm host and filer but i write on disks many more than that. I used a pool with separated mirror zil (intel s3710) and 8 ssd samsung 850 evo 1To zpool status pool: filervm2 state: ONLINE scan: resilvered 406G in 0h22m with 0 errors on Wed Sep 20 15:45:48 2017 config: NAME STATE READ WRITE CKSUM filervm2 ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c7t5002538D41657AAFd0 ONLINE 0 0 0 c7t5002538D41F85C0Dd0 ONLINE 0 0 0 mirror-2 ONLINE 0 0 0 c7t5002538D41CC7105d0 ONLINE 0 0 0 c7t5002538D41CC7127d0 ONLINE 0 0 0 mirror-3 ONLINE 0 0 0 c7t5002538D41CD7F7Ed0 ONLINE 0 0 0 c7t5002538D41CD83FDd0 ONLINE 0 0 0 mirror-4 ONLINE 0 0 0 c7t5002538D41CD7F7Ad0 ONLINE 0 0 0 c7t5002538D41CD7F7Dd0 ONLINE 0 0 0 logs mirror-1 ONLINE 0 0 0 c4t2d0 ONLINE 0 0 0 c4t4d0 ONLINE 0 0 0 i used correct ashift of 13 for samsung 850 evo zdb|grep ashift : ashift: 13 ashift: 13 ashift: 13 ashift: 13 ashift: 13 </div>But i write a lot on ssd every 5 seconds (many more than the network traffic of 2 MB/s) iostat -xn -d 1 : <div> r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 11.0 3067.5 288.3 153457.4 6.8 0.5 2.2 0.2 5 14 filervm2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 rpool 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c4t0d0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c4t1d0 0.0 552.6 0.0 17284.0 0.0 0.1 0.0 0.2 0 8 c4t2d0 0.0 552.6 0.0 17284.0 0.0 0.1 0.0 0.2 0 8 c4t4d0 1.0 233.3 48.1 10051.6 0.0 0.0 0.0 0.1 0 3 c7t5002538D41657AAFd0 5.0 250.3 144.2 13207.3 0.0 0.0 0.0 0.1 0 3 c7t5002538D41CC7127d0 2.0 254.3 24.0 13207.3 0.0 0.0 0.0 0.1 0 4 c7t5002538D41CC7105d0 3.0 235.3 72.1 10051.6 0.0 0.0 0.0 0.1 0 3 c7t5002538D41F85C0Dd0 0.0 228.3 0.0 16178.7 0.0 0.0 0.0 0.2 0 4 c7t5002538D41CD83FDd0 0.0 225.3 0.0 16210.7 0.0 0.0 0.0 0.2 0 4 c7t5002538D41CD7F7Ed0 0.0 282.3 0.0 19991.1 0.0 0.0 0.0 0.2 0 5 c7t5002538D41CD7F7Dd0 0.0 280.3 0.0 19871.0 0.0 0.0 0.0 0.2 0 5 c7t5002538D41CD7F7Ad0 </div><div>I used zvol of 64k, i try with 8k and problem is the same. zfs get all filervm2/hdd-110022a : NAME PROPERTY VALUE SOURCE filervm2/hdd-110022a type volume - filervm2/hdd-110022a creation Tue May 16 10:24 2017 - filervm2/hdd-110022a used 5.26G - filervm2/hdd-110022a available 2.90T - filervm2/hdd-110022a referenced 5.24G - filervm2/hdd-110022a compressratio 3.99x - filervm2/hdd-110022a reservation none default filervm2/hdd-110022a volsize 25G local filervm2/hdd-110022a volblocksize 64K - filervm2/hdd-110022a checksum on default filervm2/hdd-110022a compression lz4 local filervm2/hdd-110022a readonly off default filervm2/hdd-110022a copies 1 default filervm2/hdd-110022a refreservation none default filervm2/hdd-110022a primarycache all default filervm2/hdd-110022a secondarycache all default filervm2/hdd-110022a usedbysnapshots 15.4M - filervm2/hdd-110022a usedbydataset 5.24G - filervm2/hdd-110022a usedbychildren 0 - filervm2/hdd-110022a usedbyrefreservation 0 - filervm2/hdd-110022a logbias latency default filervm2/hdd-110022a dedup off default filervm2/hdd-110022a mlslabel none default filervm2/hdd-110022a sync standard local filervm2/hdd-110022a refcompressratio 3.99x - filervm2/hdd-110022a written 216K - filervm2/hdd-110022a logicalused 20.9G - filervm2/hdd-110022a logicalreferenced 20.9G - filervm2/hdd-110022a snapshot_limit none default filervm2/hdd-110022a snapshot_count none default filervm2/hdd-110022a redundant_metadata all default </div><div>Sorry for my bad english. </div><div>What can be the problem ? thanks </div><div>Best regards, </div><div>Anthony </div><div> </div></div>