Date: Wed, 5 Oct 2016 20:22:39 +0200 From: Michael Osipov <1983-01-06@gmx.net> To: freebsd-geom@freebsd.org Subject: Abysmally slow gvinum RAID5 on three drives Message-ID: <e3726f09-60e5-a030-bc8b-c0e479e681a3@gmx.net>
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Hi folks,
I have created a RAID5 wie gvinum on three 200 GB IDE disks while the
formatted disks do sequentially 20 to 50 MB/s, in RAID5 mode they to no
more than 100 kB/s -- yet that is kilobytes!
I am on:
# uname -a
FreeBSD bsd1home 10.3-RELEASE-p7 FreeBSD 10.3-RELEASE-p7 #0: Thu Aug 11
18:37:29 UTC 2016
root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
The following CPU is used:
# grep -i cpu /var/run/dmesg.boot
CPU: Intel(R) Pentium(R) 4 CPU 2.40GHz (2405.51-MHz 686-class CPU)
cpu0: <ACPI CPU> on acpi0
RAM: 2 GiB, swap: 2,5 GiB
Chipset and controller:
hostb0@pci0:0:0:0: class=0x060000 card=0x80b21043 chip=0x25608086
rev=0x03 hdr=0x00
vendor = 'Intel Corporation'
device = '82845G/GL[Brookdale-G]/GE/PE DRAM Controller/Host-Hub
Interface'
class = bridge
subclass = HOST-PCI
atapci0@pci0:2:13:0: class=0x018000 card=0x00051103 chip=0x00041103
rev=0x03 hdr=0x00
vendor = 'HighPoint Technologies, Inc.'
device = 'HPT366/368/370/370A/372/372N'
class = mass storage
My hard disks (system is on a separate disk and controller):
# camcontrol devlist | grep WDC
<WDC WD2000JB-00GVA0 08.02D08> at scbus0 target 0 lun 0 (ada0,pass0)
<WDC WD2000JB-00FUA0 15.05R15> at scbus0 target 1 lun 0 (ada1,pass1)
<WDC WD2000JB-00EVA0 15.05R15> at scbus1 target 0 lun 0 (ada2,pass2)
I have tested on the raw vinum device and on one with UFS:
# gvinum raid5 -n data ada0 ada1 ada2
# gvinum start data
# dd if=/dev/zero bs=1M count=10240 | pv -s 10G -treab --progress >
/dev/gvinum/data
2260+0 records out
2369781760 bytes transferred in 252.553715 secs (9383278 bytes/sec)
# newfs -j /dev/gvinum/data
/dev/gvinum/data: 381564.0MB (781443072 sectors) block size 32768,
fragment size 4096
using 610 cylinder groups of 626.22MB, 20039 blks, 80256 inodes.
with soft updates
...
Using inode 4 in cg 0 for 33554432 byte journal
newfs: soft updates journaling set
# mount /dev/gvinum/data /mnt
# dd if=/dev/zero bs=1M count=10240 | pv -s 10G -treab --progress >
/mnt/file.bin
4+0 records out
4194304 bytes transferred in 75.191040 secs (55782 bytes/sec)
4.75MiB 0:01:20 [48.7KiB/s] [60.2KiB/s] [> ] 0%
ETA 1:23:53:0
Any idea what the problem is? How can I investigate on the penality in
performance?
Other geom classes like concat, stripe, raid3 perform very well.
Thanks,
Michael
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