Re: port-amd64/57266: Poor disk performance on VirtualBox vioscsi0 and NetBSD 10.0_BETA

[Bartek Krawczyk <bbartlomiej.mail%gmail.com@localhost>]

The following reply was made to PR port-amd64/57266; it has been noted by GNATS.

From: Bartek Krawczyk <bbartlomiej.mail%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost, port-amd64-maintainer%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-amd64/57266: Poor disk performance on VirtualBox vioscsi0
 and NetBSD 10.0_BETA
Date: Sun, 12 Mar 2023 12:47:12 +0100

 On 12/03/2023 12:05, Michael van Elst wrote:
 > The following reply was made to PR port-amd64/57266; it has been noted by GNATS.
 > 
 > From: mlelstv%serpens.de@localhost (Michael van Elst)
 > To: gnats-bugs%netbsd.org@localhost
 > Cc:
 > Subject: Re: port-amd64/57266: Poor disk performance on VirtualBox vioscsi0 and NetBSD 10.0_BETA
 > Date: Sun, 12 Mar 2023 11:02:08 -0000 (UTC)
 > 
 >   bbartlomiej.mail%gmail.com@localhost (Bartek Krawczyk) writes:
 >   
 >   >It shows:
 >   >messages:Mar 12 11:06:11 netbsd /netbsd: [   1.0546101] vioscsi0:
 >   >cmd_per_lun 128 qsize 1024 seg_max 126 max_target 2 max_lun 1
 >   
 >   If the possible 128 commands get queued, each should take at most 8
 >   queue entries (but with 64k blocks and 4k pages it can take 18 (or 17?)).
 >   
 >   >logs didn't show any errors but unpacking pkgsrc also took ~30min. The
 >   >VM has 12 vCPUs (Ryzen 9 3900x) and ~16GB of RAM assigned.
 >   
 >   Unpacking pkgsrc can vary in time, I get natively:
 >   
 >   - 42s to a journaled ffs on NVME.
 >   - 10m to a not-journaled ffs on SATA HDD.
 >   
 >   So 30m is slower, but on a virtualized disk maybe not that much.
 >   A slow disk also makes the queue larger (and the risk to overflow it)
 >   which makes it even slower.
 >   
 >   I tried on qemu with vioscsi, but the queue was never large and unpacking
 >   pgksrc never overflowed it.
 >   
 >   [   1.0000070] vioscsi0: cmd_per_lun 128 qsize 256 seg_max 254 max_target 255 max_lun 16383
 >   
 >   
 >   To get some information on how fast your emulated disk is, you could
 >   compare the unpacking (lots of transactions) with reading the raw
 >   disk sequentially (bandwidth matters) using e.g.:
 >   
 >   dd if=/dev/rdk0 of=/dev/null bs=1024k count=10240
 >   
 
 The host (Windows) has a NVME disk WDC WDS100T2B0C-00PXH0 which in 
 general performs very well.
 
 netbsd# dd if=/dev/rdk0 of=/dev/null bs=1024k count=10240
 10240+0 records in
 10240+0 records out
 10737418240 bytes transferred in 58.141 secs (184678939 bytes/sec)
 
 -- 
 Regards
 Bartek Krawczyk