On Thu, 28 Jun 2007, Justin Piszcz wrote:
On Thu, 28 Jun 2007, Peter Rabbitson wrote:
Justin Piszcz wrote:
On Thu, 28 Jun 2007, Peter Rabbitson wrote:
Interesting, I came up with the same results (1M chunk being superior)
with a completely different raid set with XFS on top:
...
Could it be attributed to XFS itself?
Peter
Good question, by the way how much cache do the drives have that you are
testing with?
I believe 8MB, but I am not sure I am looking at the right number:
[EMAIL PROTECTED]:~# hdparm -i /dev/sda
/dev/sda:
Model=aMtxro7 2Y050M , FwRev=AY5RH10W,
SerialNo=6YB6Z7E4
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=DualPortCache, BuffSize=7936kB, MaxMultSect=16, MultSect=?0?
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-7 T13 1532D revision 0: ATA/ATAPI-1
ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7
* signifies the current active mode
[EMAIL PROTECTED]:~#
1M chunk consistently delivered best performance with:
o A plain dumb dd run
o bonnie
o two bonnie threads
o iozone with 4 threads
My RA is set at 256 for the drives and 16384 for the array (128k and 8M
respectively)
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Have you also tried tuning:
1. nr_requests per each disk? I noticed 10-20 seconds faster speed (overall)
with bonnie tests when I set all disks in the array to 512k.
echo 512 > /sys/block/"$i"/queue/nr_requests
2. Also disable NCQ.
echo 1 > /sys/block/"$i"/device/queue_depth
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Also per XFS:
noatime,logbufs=8
I am testing various options, so far the logbufs=8 option is detrimental,
making the entire bonnie++ run a little slower. I believe the default is
2 and it uses 32k(?) buffers (shown below) if the blocksize is less than
16K I am trying with: noatime,logbufs=8,logbsize=262144 currently.
logbufs=value
Set the number of in-memory log buffers. Valid numbers range
from 2-8 inclusive. The default value is 8 buffers for filesys-
tems with a blocksize of 64K, 4 buffers for filesystems with a
blocksize of 32K, 3 buffers for filesystems with a blocksize of
16K, and 2 buffers for all other configurations. Increasing the
number of buffers may increase performance on some workloads at
the cost of the memory used for the additional log buffers and
their associated control structures.
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
