[SOLVED] Writes in XFS filesystem very very slow.

ddenial · 12-06-2019, 08:54 AM

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	0m0.809s

Why XFS so slow?

Thanks

ddenial · 12-06-2019, 09:12 AM

Nevermind. I had taken a snapshot of / filesystem and forgot to remove that. I removed the snapshot and now it 98 Mb/s.

Sorry about this, thanks.