[SOLVED] Writes in XFS filesystem very very slow.

Hello

I just installed CentOS 7.7. I have got a / partition with XFS filesystem and /data partition with ext4 filesystem. It's a brand new install. But the write speed are an ocean apart between them.

Code:$ df -hT /bak /
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda5 ext4 394G 11G 363G 3% /bak
/dev/mapper/vgh-root xfs 200G 31G 170G 16% /

Ext4 Partition:
$ time dd if=/dev/zero of=test-ext4.dd bs=4096 count=262144 conv=fdatasync
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 9.74537 s, 110 MB/s

real 0m9.747s
user 0m0.169s
sys 0m0.731s

XFS Partition:
$ time dd if=/dev/zero of=test-xfs.dd bs=4096 count=262144 conv=fdatasync
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 87.0983 s, 12.3 MB/s

real 1m27.100s
user 0m0.172s
sys 0m0.809sWhy XFS so slow?

Thanks