Almalinux and integritysetup speed problem

10 Apr 2024

      Hi list,
I'm trying on a spare machine dm-integrity with mdadm raid1.
This is an old machine (i7-2600k). I'm using 2x500GB wd caviar black SATA3.

I'm trying to run some test and see how much performance changes using 
dm-integrity.

First I created a raid1 with mdadm and checked the performances and 
writing 50G I got 100 MB/s

Then I destroied the md device and on every disk I run:

	# integritysetup format --integrity xxhash64 /dev/sdb1
	# integritysetup format --integrity xxhash64 /dev/sdc1

During this process the performances was good ~95MB/s.
After this I opened the devices with:

	# integritysetup open integrity xxhash64 /dev/sdb1 sdb1
	# integritysetup open integrity xxhash64 /dev/sdc1 sdc1

and created the mdadm array with:

	# mdadm --create /dev/md10 --level=raid1 --raid-devices=2 
/dev/mapper/sdb1 /dev/mapper/sdc1

and reading on /proc/mdstat I got this:

[>....................]  resync =  1.1% (4929792/443175424) 
finish=677.3min speed=10782K/sec

Why there is so big drop on speed during the sync?

I'm missing something?

I'll need 11 hours to sync 2x500GB hdd? Why so slow?

Before this I tried the same on a newer machine with i7 8700k and 2x2TB 
WD gold and I get a drop sync speed at ~35MB/s.

There is something that I can do to improve this?

Thank you in advance.

Alessandro.

Alessandro Baggi

Jonathan Wright

Alessandro Baggi

Jonathan Wright

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