On Tue 25 Aug 2020 06:54:15 PM CEST, Brian Foster wrote:
> If I compare this 5m fio test between XFS and ext4 on a couple of my
> systems (with either no prealloc or full file prealloc), I end up seeing
> ext4 run slightly faster on my vm and XFS slightly faster on bare metal.
> Either way, I don't see that huge disparity where ext4 is 5-6 times
> faster than XFS. Can you describe the test, filesystem and storage in
> detail where you observe such a discrepancy?
Here's the test:
fio --filename=/path/to/file.raw --direct=1 --randrepeat=1 \
--eta=always --ioengine=libaio --iodepth=32 --numjobs=1 \
--name=test --size=25G --io_limit=25G --ramp_time=0 \
--rw=randwrite --bs=4k --runtime=300 --time_based=1
The size of the XFS filesystem is 126 GB and it's almost empty, here's
the xfs_info output:
meta-data=/dev/vg/test isize=512 agcount=4, agsize=8248576
blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1,
rmapbt=0
= reflink=0
data = bsize=4096 blocks=32994304, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=16110, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
The size of the ext4 filesystem is 99GB, of which 49GB are free (that
is, without the file used in this test). The filesystem uses 4KB
blocks, a 128M journal and these features:
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index
filetype needs_recovery extent flex_bg
sparse_super large_file huge_file uninit_bg
dir_nlink extra_isize
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
In both cases I'm using LVM on top of LUKS and the hard drive is a
Samsung SSD 850 PRO 1TB.
The Linux version is 4.19.132-1 from Debian.
Berto
