Hi there
I'm having exactly the same problem on the same hardware. I used iozone
to compare disk performance figures, and found that native (i.e. Fedora
Core 3 kernel 2.6.10-1.770_FC3smp) throughput of the SATA drive
outperforms xen throughput by a factor of roughly 3.
Logs and config info follow below, I'll gladly attach anything else that
may be of use.
Help will be greatly appreciated, thanks a bunch.
Andres
lsmod (recompiled dom0 kernel with closely as possible non-xen kernel
config options):
Module Size Used by
iptable_filter 2304 0
ip_tables 19968 1 iptable_filter
intel_mch_agp 8208 0
agpgart 28072 1 intel_mch_agp
ata_piix 6916 3
libata 40452 1 ata_piix
aic7xxx 212056 0
sd_mod 12688 5
scsi_mod 76616 3 libata,aic7xxx,sd_mod
hdparm /dev/sdb:
/dev/sdb:
IO_support = 0 (default 16-bit)
readonly = 0 (off)
readahead = 256 (on)
geometry = 19452/255/63, sectors = 160000000000, start = 0
Same response under non-xen kernel.
hdparm -d 1 /dev/sdb:
/dev/sdb:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Inappropriate ioctl for device
However, I get the same response under non-xen kernel.
My lspci and dmesg output are very similar to those of Martti,
lspci | grep SATA:
00:1f.2 IDE interface: Intel Corp. 6300ESB SATA Storage Controller (rev 02)
dmesg:
ata1: SATA max UDMA/133 cmd 0x170 ctl 0x376 bmdma 0xFEA8 irq 15
ata1: dev 0 cfg 49:2f00 82:346b 83:7f01 84:4003 85:3469 86:3e01 87:4003
88:207f
ata1: dev 0 ATA, max UDMA/133, 78125000 sectors: lba48
ata1: dev 1 cfg 49:2f00 82:3469 83:7f61 84:4003 85:3469 86:3e41 87:4003
88:207f
ata1: dev 1 ATA, max UDMA/133, 312500000 sectors: lba48
ata1: dev 0 configured for UDMA/133
ata1: dev 1 configured for UDMA/133
scsi2 : ata_piix
Vendor: ATA Model: ST340014AS Rev: 8.05
Type: Direct-Access ANSI SCSI revision: 05
SCSI device sda: 78125000 512-byte hdwr sectors (40000 MB)
SCSI device sda: drive cache: write back
SCSI device sda: 78125000 512-byte hdwr sectors (40000 MB)
SCSI device sda: drive cache: write back
sda: sda1 sda2
Attached scsi disk sda at scsi2, channel 0, id 0, lun 0
Vendor: ATA Model: WDC WD1600JD-75H Rev: 08.0
Type: Direct-Access ANSI SCSI revision: 05
SCSI device sdb: 312500000 512-byte hdwr sectors (160000 MB)
SCSI device sdb: drive cache: write back
SCSI device sdb: 312500000 512-byte hdwr sectors (160000 MB)
SCSI device sdb: drive cache: write back
sdb: sdb1
Attached scsi disk sdb at scsi2, channel 0, id 1, lun 0
Hi!
I have few Dell PowerEdge 750 servers (each with 4 GB RAM and 250 GB SATA disk)
in our lab. The disk controllers and the disks are identified like this:
# lspci | grep SATA
0000:00:1f.2 IDE interface: Intel Corp. 6300ESB SATA Storage Controller (rev 02)
ata1: SATA max UDMA/133 cmd 0x170 ctl 0x376 bmdma 0xFEA8 irq 15
ata1: dev 0 cfg 49:2f00 82:3469 83:7f61 84:4003 85:3469 86:3e41 87:4003 88:207f
ata1: dev 0 ATA, max UDMA/133, 488281250 sectors: lba48
ata1: dev 0 configured for UDMA/133
scsi0 : ata_piix
Vendor: ATA Model: WDC WD2500JD-75H Rev: 08.0
Type: Direct-Access ANSI SCSI revision: 05
SCSI device sda: 488281250 512-byte hdwr sectors (250000 MB)
SCSI device sda: drive cache: write back
SCSI device sda: 488281250 512-byte hdwr sectors (250000 MB)
SCSI device sda: drive cache: write back
sda: sda1 sda2 sda3
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
When running bonnie with the normal Linux 2.6.11 kernel I get numbers like
these:
Version 1.03 ------Sequential Output------ --Sequential Input-
--Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
xen2 8G 29093 98 56445 6 20761 3 25706 88 53444 3 176.3 0
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 4081 99 +++++ +++ +++++ +++ 4125 99 +++++ +++ 12994 99
So far so good.
If I now I reboot to the Xen domain-0 (Xen 2.0.6 and Linux 2.6.11) and run
bonnie again (without any active domain-U) I get these numbers:
Version 1.03 ------Sequential Output------ --Sequential Input-
--Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
xen2 2G 5798 95 50965 53 23156 15 6450 98 55912 16 128.1 1
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 664 99 +++++ +++ +++++ +++ 676 99 +++++ +++ 2699 99
Now, the block output and input seem to be almost same. However, "Per Chr"
and
sequential and random file creation are very slow compared to the normal Linux
kernel. The disk should still be in UDMA/133 mode with domain-0:
ata1: SATA max UDMA/133 cmd 0x170 ctl 0x376 bmdma 0xFEA8 irq 15
ata1: dev 0 cfg 49:2f00 82:3469 83:7f61 84:4003 85:3469 86:3e41 87:4003 88:207f
ata1: dev 0 ATA, max UDMA/133, 488281250 sectors: lba48
ata1: dev 0 configured for UDMA/133
scsi0 : ata_piix
Vendor: ATA Model: WDC WD2500JD-75H Rev: 08.0
Type: Direct-Access ANSI SCSI revision: 05
Any ideas why this difference is so huge with domain-0?
Martti
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