Re: Dell Perc 5/i Performance issues

I've tried almost everything now.
The battery is probably fine:
mfiutil show battery
mfi0: Battery State:
  Manufacture Date: 7/25/2009
     Serial Number: 3716
      Manufacturer: SMP-PA1.9
             Model: DLFR463
         Chemistry: LION
   Design Capacity: 1800 mAh
    Design Voltage: 3700 mV
    Current Charge: 99%

My results:
Settings:
Raid5:
Stripe: 64k
mfiutil cache 0
mfi0 volume mfid0 cache settings:
       I/O caching: writes
     write caching: write-back
        read ahead: none
drive write cache: default
Raid0:
Stripe: 64k
mfiutil cache 0
mfi0 volume mfid0 cache settings:
       I/O caching: writes
     write caching: write-back
        read ahead: none
drive write cache: default

Tried to play around with this as well, with almost no difference.

Raid5
read:
dd if=/dev/mfid0 of=/dev/null bs=10M
1143+0 records in
1143+0 records out
11985223680 bytes transferred in 139.104134 secs (86160083 bytes/sec)
write:
dd if=/dev/random of=/dev/mfid0 bs=64K
22747+0 records in
22747+0 records out
1490747392 bytes transferred in 23.921103 secs (62319342 bytes/sec)

Raid0
read:
dd if=/dev/mfid0 of=/dev/null bs=64K
92470+0 records in
92470+0 records out
6060113920 bytes transferred in 47.926007 secs (126447294 bytes/sec)
write:
dd if=/dev/random of=/dev/mfid0 bs=64K
16441+0 records in
16441+0 records out
1077477376 bytes transferred in 17.232486 secs (62525939 bytes/sec)

I'm writing directly to the device so im not sure any slice issues could 
cause the problems.

-zsozso
On 2010.06.20. 4:53, Scott Long wrote:
> Two big things  can affect RAID-5 performance:
>
> 1. Battery backup.  If you don't have a working battery attached to the card, it will turn off the write-back cache, no matter what you do.  Check this.  If you're unsure, use the mfiutil tool that I added to FreeBSD a few months ago and send me the output.
>
> 2. Partition alignment.  If you're using classic MBR slices, everything gets misaligned by 63 sectors, making it impossible for the controller to optimize both reads and writes.  If the array is used for secondary storage, simply don't use an MBR scheme.  If it's used for primary storage, try using GPT instead and setting up your partitions so that they are aligned to large power-of-2 boundaries.
>
> Scott
>
> On Jun 18, 2010, at 6:27 PM, oizs wrote
>