# hardware raid extremely slow (4mb/s)

## feystorm

Ok, so I've googled around and have found other people with similar hardware have the exact same problem. The problem is extremely slow disk access.

# dd if=/dev/zero of=/tmp/zero bs=1M count=200

200+0 records in

200+0 records out

209715200 bytes (210 MB) copied, 36.8388 s, 5.7 MB/s

This is a 4 disk hardware raid-5 array. This should not be going that slow, and I'm at a loss to why (google results of others with the same problem had no solutions). No errors in dmesg.

machine: dl380 g2

kernel: 2.6.32-gentoo-r7

# lspci -k -s 01.0

00:01.0 RAID bus controller: LSI Logic / Symbios Logic 53C1510 (rev 02)

        Kernel driver in use: cpqarray

# dmesg|grep -E '(ida|cpq)'

[    0.000000] Kernel command line: root=/dev/ida/c0d0p2 console=ttyS0,115200 panic=10

[    0.775788] cpqarray: Device 0x10 has been found at bus 0 dev 1 func 0

[    0.775832] cpqarray 0000:00:01.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19

[    0.783004] IRQ 19/ida0: IRQF_DISABLED is not guaranteed on shared IRQs

[    0.789828] cpqarray: Finding drives on ida0 (Integrated Array)

[    0.796891] cpqarray ida/c0d0: blksz=512 nr_blks=426759840

[    0.802753] cpqarray: Starting firmware's background processing

[    0.803148]  ida/c0d0: p1 p2 p4

[    0.985165] EXT4-fs (ida!c0d0p2): mounted filesystem with ordered data mode

[    6.922235] JBD: barrier-based sync failed on ida!c0d0p2-8 - disabling barriers

[    7.253469] Adding 1048552k swap on /dev/ida/c0d0p4.  Priority:-1 extents:1 across:1048552k

# cat /proc/driver/cpqarray

ida0:  Compaq Integrated Array Controller

       Board ID: 0x40400e11

       Firmware Revision: 1.50

       Controller Sig: 0xa012f710

       Memory Address: 0xf87ae000

       I/O Port: 0x2000

       IRQ: 19

       Logical drives: 1

       Physical drives: 4

       Current Q depth: 0

       Max Q depth since init: 4

Logical Drive Info:

ida/c0d0: blksz=512 nr_blks=426759840

nr_allocs = 17874

nr_frees = 17874

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## krinn

no idea but i would have check my irq to see if the card doesn't share it with another device that don't really like to share it.

cat /proc/interrputs and check irq19 only got that card running on it.

might not be that, but well, won't kill you to let the card work alone on it.

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## feystorm

Nope card is alone on that IRQ. Even tried disabling APIC as well, as APIC always seems to give me trouble. But alas, still no go. Even tried dropping back to kernel 2.6.28 (only had this box since 2.6.31). 2.6.28 got rid of the "IRQF_DISABLED is not guaranteed on shared IRQs" message, but still going slow. I'm thinking of trying the SYM53C8XX driver which will let me use the drives individually and just do a software raid-5 instead.

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## krinn

the IRQF disable wasn't there before on older kernel, but just the message, the feature was the same, just that older kernel didn't warn the user.

and my raid card have trigger the message too and performance are ok.

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## frostschutz

 *feystorm wrote:*   

> I'm thinking of trying the SYM53C8XX driver which will let me use the drives individually and just do a software raid-5 instead.

 

You do that... also you could benchmark the drives individually, if one of them is semi broke or has a bad cable or sth, and is slow because of it, all other disks have to wait for this drive to finish, so the drives will spend more time waiting than actually working...

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