Disk reads about 18 mb OVH VPS SSD 1 ubuntu16.4


#1

As i see it trough netdata disk reads are about 18mb. I ve tried https://easyengine.io/tutorials/kvm/enable-virtio-existing-vms/. Any ideas what to do next?


#2

What do you mean by “disk reads are about 18mb” ? If you want to check your disk performance, use sysbench :

apt install sysbench
sysbench --test=fileio --file-total-size=5G prepare
sysbench --test=fileio --file-total-size=5G --file-test-mode=rndrw --init-rng=on --max-time=300 --max-requests=0 run
sysbench --test=fileio --file-total-size=5G cleanup

#3

Results on sysbench

Extra file open flags: 0 128 files, 8Mb each 1Gb total file size Block size 16Kb Number of random requests for random IO: 0 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 100 requests. Calling fsync() at the end of test, Enabled. Using synchronous I/O mode Doing random r/w test Threads started! Time limit exceeded, exiting… Done.

Operations performed: 192660 Read, 128440 Write, 410881 Other = 731981 Total Read 2.9398Gb Written 1.9598Gb Total transferred 4.8996Gb (16.724Mb/sec) 1070.33 Requests/sec executed

Test execution summary: total time: 300.0022s total number of events: 321100 total time taken by event execution: 9.4803 per-request statistics: min: 0.00ms avg: 0.03ms max: 12.25ms approx. 95 percentile: 0.05ms

Threads fairness: events (avg/stddev): 321100.0000/0.00 execution time (avg/stddev): 9.4803/0.00


#4

What is the VPS used ? A custom one or from a provider like OVH, Linode or DO ?


#5

OVH VPS SSD 1, small one. Was i right?


#6

16.724Mb/sec is correct with a VPS SSD from OVH, on my last benchmark it was around 17Mb/sec. Public cloud instance are better with around 45Mb/sec, and with a dedicated server you can get up to 100Mb/sec. Anyway, the guide about virtio drivers will not help you because you can’t make any change on your VPS configuration, it require to create your own VPS on a dedicated server with Proxmox VE or another virtualization solution.


#7

Ok, got it! this speed is an issue for you?


#8

It’s enough for almost all usage, sysbench benchmark the disk with random read/write access and it’s only used to check disk performance. But your MySQL server will probably never write more than 1Mb/sec on your disk, even with high-traffic. That’s why caching solution make wordpress faster, because RAM is always faster than disk.


#9

yeah, make sense as you say it. Thanks a lot!


#10