Re: measuring swap partition speed

On Thu, 21 Dec 2023, at 18:56, Ronald Klop wrote:
> A bit weird that a simple dd is so slow.
>
> Just a quick thought.
> Are your partitions aligned properly?

no idea. How would I check? The system when installed, 
the auto-zfs option was selected, block size set to 4k. The swap 
was changed from the default 2gb to 12gb. geli encryption is
active for the zfs filesystem but not for swap. It's only the swap
that shows performance issues.

> Is other IO going on on the same time?

not really, the tests were done with cron jobs deactivated, almost completely idle,
swap was not being used at all.

> What does gstat say about %util, queue length and all the other stats 
> while running the dd? Or "iostat -x -d 1".

I'll try that next, thanks

> Could you try if another disk has the same issues?

no spare or equivalent disk for this arch.

> How is your disk connected? USB-to-SATA-adapter? Any output of dmesg?

Regular usb3 connection. 

da0: 400.000MB/s transfers
da0: 953869MB (1953525168 512 byte sectors)
da0: quirks=0x2<NO_6_BYTE>
da0: Delete methods: <NONE(*),ZERO>
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