Why isn't the speed of raid-0 twice of the non-raid devices?
I wonder the rate of data should be twice the non-raid, if data transfering from or to on raid device but it is not happening. Even raid device seems to be slower than non-raid.
I got four ultra ATA 100 seagate drives 120 GB each.
hda, hdb the non-raid regular HDD (see !!!kernel log2)
sda is a raid-0 device comprise of to ultra ATA 100 on promise fast track controller(see !!!kernel log3)
Here is a math of transfering 1 GB file in different route
1- hda to hdb 50 secs (20.5 MB/s)
2- hda to hda 81 secs (13 MB/s)
3- sda to hda 50 secs (20.5 MB/s)
4- sda to sda 81 secs (13 MB/s)
5- hda to sda 77 secs (13 MB/s)
*These test has been taken so many times and the result are very close.
Following are more details
I am using the RH8 on Intel S845WDE-1 having Promise 20267 on board controller and 512 DDR266 RAM. The bios is configured with array of 2 disk on raid 0.
I had intall RH8 as per given instruction in readme on promise driver that is booting linux with
Boot: linux ide0=ox... expert (see !!!kernel log1)
and install the driver downloaded from the intel downloads page.
I had formated the raid device by using the mke2fs command
# mke2fs -j -R stride=16 /dev/sda
The device is activated to save anything.
The both Raid harddrives (/dev/sda) are conneted with different channel as Master Drive
I had check HDD, when I used them as regular drives its fine.
No Hardware fault any more!
I dont have option to switch on the Linux software raid. I must use the Hardware/Firmware Raid on my board.
Here are details:
################### Kernel Setup Log ################
Linux version 2.4.18-14 (bhcompile@stripples.devel.redhat.com) (gcc version 3.2 20020903 (Red Hat Linux 8.0 3.2-7)) #1 Wed Sep 4 13:35:50 EDT 2002
BIOS-provided physical RAM map:
...
!!! Kernel log1
Kernel command line: ro root=LABEL=/ ide0=0x1f0,0x3f6 ide1=0x170,0x376 ide2=0 ide3=0 ide4=0 ide5=0 ide6=0 ide7=0 ide8=0 ide9=0
ide_setup: ide0=0x1f0,0x3f6
ide_setup: ide1=0x170,0x376
ide_setup: ide2=0
ide_setup: ide3=0
ide_setup: ide4=0
ide_setup: ide5=0
ide_setup: ide6=0
ide_setup: ide7=0
ide_setup: ide8=0
ide_setup: ide9=0
...
...
Real Time Clock Driver v1.10e
oprofile: can't get RTC I/O Ports
block: 992 slots per queue, batch=248
Uniform Multi-Platform E-IDE driver Revision: 6.31
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
PIIX4: IDE controller on PCI bus 00 dev f9
PIIX4: chipset revision 5
PIIX4: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xffa0-0xffa7, BIOS settings: hdaMA, hdbMA
PDC20267: IDE controller on PCI bus 02 dev 70
PCI: Found IRQ 9 for device 02:0e.0
PDC20267: chipset revision 2
PDC20267: not 100% native mode: will probe irqs later
PDC20267: (U)DMA Burst Bit ENABLED Primary MASTER Mode Secondary MASTER Mode.
PDC20267: too many IDE interfaces, no room in table
PDC20267: too many IDE interfaces, no room in table
PDC20267: neither IDE port enabled (BIOS)
!!!kernel log2
hda: ST3120022A, ATA DISK drive
hdb: ST3120022A, ATA DISK drive
ide2: ports already in use, skipping probe
ide3: ports already in use, skipping probe
ide4: ports already in use, skipping probe
ide5: ports already in use, skipping probe
ide6: ports already in use, skipping probe
ide7: ports already in use, skipping probe
ide8: ports already in use, skipping probe
ide9: ports already in use, skipping probe
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
blk: queue c03c0004, I/O limit 4095Mb (mask 0xffffffff)
blk: queue c03c0004, I/O limit 4095Mb (mask 0xffffffff)
hda: 234441648 sectors (120034 MB) w/2048KiB Cache, CHS=14593/255/63, UDMA(100)
blk: queue c03c0140, I/O limit 4095Mb (mask 0xffffffff)
blk: queue c03c0140, I/O limit 4095Mb (mask 0xffffffff)
hdb: 234441648 sectors (120034 MB) w/2048KiB Cache, CHS=14593/255/63, UDMA(100)
ide-floppy driver 0.99.newide
Partition check:
hda: hda1 hda2 hda3
hdb: unknown partition table
FDC 0 is a post-1991 82077
NET4: Frame Diverter 0.46
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
ide-floppy driver 0.99.newide
md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 4096 buckets, 32Kbytes
TCP: Hash tables configured (established 32768 bind 65536)
Linux IP multicast router 0.06 plus PIM-SM
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
RAMDISK: Compressed image found at block 0
Freeing initrd memory: 241k freed
VFS: Mounted root (ext2 filesystem).
SCSI subsystem driver Revision: 1.00
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
!!!kernel log3
Promise FastTrak Series Linux Driver Version 1.2.0.15
scsi0 : FASTTRAK
Vendor: Promise Model: 2+0 Stripe/RAID0 Rev: 1.10
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
SCSI device sda: 468882944 512-byte hdwr sectors (240068 MB)
sda: unknown partition table
Journalled Block Device driver loaded
kjournald starting. Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
Freeing unused kernel memory: 212k freed
usb.c: registered new driver usbdevfs
usb.c: registered new driver hub
usb-uhci.c: $Revision: 1.275 $ time 13:44:31 Sep 4 2002
usb-uhci.c: High bandwidth mode enabled
...
################### Other Maths ###################
----------------------------------------------------------------------------------
# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: Promise Model: 2+0 Stripe/RAID0 Rev: 1.10
Type: Direct-Access ANSI SCSI revision: 02
----------------------------------------------------------------------------------
# cat /proc/pci
...
Bus 2, device 14, function 0:
RAID bus controller: Promise Technology, Inc. 20267 (rev 2).
IRQ 9.
Master Capable. Latency=32.
I/O at 0xdff0 [0xdff7].
I/O at 0xdfe4 [0xdfe7].
I/O at 0xdfa8 [0xdfaf].
I/O at 0xdfe0 [0xdfe3].
I/O at 0xdf00 [0xdf3f].
Non-prefetchable 32 bit memory at 0xfeaa0000 [0xfeabffff].
...
----------------------------------------------------------------------------------
# cat /proc/ide/pdc202xx
PDC20267 Chipset.
------------------------------- General Status ---------------------------------
Burst Mode : enabled
Host Mode : Normal
Bus Clocking : 66 External
IO pad select : 10 mA
Status Polling Period : 0
Interrupt Check Status Polling Delay : 0
--------------- Primary Channel ---------------- Secondary Channel -------------
enabled enabled
66 Clocking disabled disabled
Mode MASTER Mode MASTER
FIFO Empty FIFO Empty
--------------- drive0 --------- drive1 -------- drive0 ---------- drive1 ------
DMA enabled: no no no no
DMA Mode: UDMA 4 NOTSET UDMA 4 NOTSET
PIO Mode: PIO 4 NOTSET PIO 4 NOTSET
----------------------------------------------------------------------------------
# cat /proc/partitions
major minor #blocks name rio rmerge rsect ruse wio wmerge wsect wuse running use aveq
8 0 234441472 sda 102931 2266114 18952320 1941126 169412 4789483 39672208 2521385 0 1679126 4815910
3 0 117220824 hda 158268 1985197 17147260 4264425 47901 566852 4919776 5416146 -3 3892083 6373799
3 1 4192933 hda1 13028 18793 254546 83560 12124 72068 675120 3027902 0 263269 3113320
3 2 111973050 hda2 145229 1966373 16892594 4180806 35777 494784 4244656 2388244 0 590626 6584490
3 3 1052257 hda3 9 25 104 41 0 0 0 0 0 41 41
3 64 117220824 hdb 102094 1473798 12607106 2129949 85597 1230469 10528808 3382836 -3 3901315 2224366
------------------------------------------------------------------------------------------
# hdparm -Tt /dev/hda
/dev/hda:
Timing buffer-cache reads: 128 MB in 0.36 seconds =358.14 MB/sec
Timing buffered disk reads: 64 MB in 1.40 seconds = 45.70 MB/sec
------------------------------------------------------------------------------------------
# hdparm -Tt /dev/hdb
/dev/hdb:
Timing buffer-cache reads: 128 MB in 0.34 seconds =374.52 MB/sec
Timing buffered disk reads: 64 MB in 1.21 seconds = 52.68 MB/sec
------------------------------------------------------------------------------------------
# hdparm -Tt /dev/sda
/dev/sda:
Timing buffer-cache reads: 128 MB in 0.35 seconds =368.20 MB/sec
Timing buffered disk reads: 64 MB in 0.96 seconds = 66.47 MB/sec
Thats all
I would appreciate any help.
Sorry for the long message
