Questions tagged [fio]
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18
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understanding fio test results - 90th percentiles benchmark - Latency --> avg/stdev?
What are the relationships in storage benchmarking with fio between the average(avg) and standard deviation (stdev) at latency?
Avg / stdev at latency is important for sequential or random test?
Most ...
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60
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How to best control variability in fio for a reliable filesystem benchmark?
for a work project, I am tasked to create a benchmarking tool to measure the read/write performance of a physical device, which acts much like a database server. Currently I am focused on the ...
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1
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45
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How does the --bsize option in fio work?
Since fio is a benchmarking tool that for each run, should simulate a real I/O workload, how does the --bsize option fit with that? My understanding is that the filesystem has a set block size for ...
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1
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102
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Why Disk stats show many read operations when I measure NVME squance write with fio and mmap as ioengine
Here is my fio configure and report:
# cat fio-write.fio
[global]
name=fio-seq-writes
filename=test
rw=write
bs=1M
direct=0
numjobs=1
[file1]
size=1G
ioengine=mmap
iodepth=1
# fio --version
fio-3.30
...
- 337
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56
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Doing fio testing and hotplug remove the SSD
When disk is in use, ex: doing fio testing ( random write ), remove the PCIe SSD at the same time.
Should I expect there is no any I/O error since the system support hotplug?
- 697
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1
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80
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RAMDisk disappears after random read tests
I have created 60GB RAMDisk using the command modprobe brd rd_size=62914560. It creates 16 RAMDisks and I use /dev/ram1. The linux is CentOS 7.5 with kernel version 3.10. I don't make any filesystems ...
1
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84
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FIO processes go from aiospn to 100% CPU
I'm using FreeBSD 12.2 and FIO 3.24. The ioengine parameter is posixaio. Testing NVMe drives. During the initial part of our testing, we hit the unit under test with a QD of 32 and numjobs of 4 for 3 ...
- 31
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730
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Extremely poor performance for ZFS 4k randwrite on NVMe compared to XFS?
I've been a fan of ZFS for a long time and I use it on my home NAS, but in testing its viability for production workloads I've found that its performance is inconceivably bad compared with XFS on the ...
- 61
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200
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Multiple Threads Cannot Access the Same RAMdisk Created by modprobe
I have created RAMdisks of 60GB using modprove brd rd_size=62914560 on CentOS 7.5. Checking the results, fdisk -l /dev/ram* shows 16 ram block devices of 60GB size (/dev/ram0, /dev/ram1, ..., /dev/...
2
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1
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400
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Does it make sense to use queue-depth when doing synchronous IO benchmark?
Does it make sense to have a queue depth > 1 when doing a synchronous IO benchmark?
I was expecting the same result a of QD1, but QD32 does give better result?
I thought it would just be ignored. ...
- 649
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696
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Understanding "Laying out IO file" in fio
I am trying to understand what really happens when in the "Laying out IO file". I have btrfs installed on a raw block device and whenever I run fio with the following configuration, I see ...
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1
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201
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What makes completion latency various in Fio benchmark with NVMe SSD?
I'm trying to figure out the completion latency of fio benchmark with NVMe SSD.
I made following fio script to test benchmark in fio.
I used following options.
rw=read, ioengine=sync, direct=1
So, I ...
- 3
1
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1
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45
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Quickly assemble raid5 for perf test
I'd like to run a series of fio-based performance tests on a few drives in various RAID and non-RAID configurations. When assembling drives in RAID5, the rebuild process takes an incredibly long time (...
- 945
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2k
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fio: how to test for bs less than 1 filesystem-block size?
I am testing my SSDs and have two questions.
SNIA has published specification PTS (SNIA) to test SSD . In many cases, it requires device to be tested for bs=0.5Ki !! What is the rational behind this? ...
- 173
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117
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How does a utility 'fio' perform VFS like operations on raw unformatted devices with no filesystem on them?
I understand that one cannot do VFS operations on a medium with no filesystem.
Given that, how does a utility like fio perform VFS-like read/write/seek operations on raw devices?
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194
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fio: how to write 2X user capacity?
My system has SSDs and I wanted to run some benchmark tests on it based on SSS PTS (SNIA). For example, for IOPS test, the spec suggested to use QD=32, TC=4 and for doing IO, the spec says following.
...
- 173
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543
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fio: how to reduce verbosity?
When I run fio command, I get huge file with following lines which fills up the entire space. I am interested in only the final fio output summary. How can I reduce this fio verbosity?
::::
Jobs: 4 (f=...
- 173
1
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2
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708
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Why is overwiting a file slower than writing to a new file?
I noticed that sequentially overwriting an existing file may be much slower than writing a new file. Example:
mkdir del
cd del
fio --name=seqwrite --rw=write --ioengine=sync --bs=128KiB --size=10GiB ...
- 55.6k