Megaraid2: Dell PERC 4/DC connected to Dell Powervault 220S, poor performance.

Paul Bright Paul.Bright at gossinteractive.com
Tue Aug 7 07:18:38 CDT 2007


Hi Patrick,

Yes, I have tried the deadline scheduler.

Paul.
 

-----Original Message-----
From: linux-poweredge-bounces at dell.com
[mailto:linux-poweredge-bounces at dell.com] On Behalf Of Patrick Schreurs
Sent: 07 August 2007 11:06
To: Paul Bright
Cc: linux-poweredge at dell.com
Subject: Re: Megaraid2: Dell PERC 4/DC connected to Dell Powervault
220S,poor performance.

Hi Paul,

Did you try with
elevator=deadline ?

Patrick Schreurs

On Mon, 6 Aug 2007, Paul Bright wrote:

> Hi,
>
> Im wondering if anyone can help me out with the megaraid2 driver.  Ive

> got a Dell PERC 4/DC connected to a Dell powervault 220S, cluster mode

> is enabled (write cache OFF) because eventually there will be two 
> machines connected to the powervault for shared scsi.  Ive tried the 
> Dell PERC 4 card in 2 different servers; a Dell 1850 and currently its

> all set up on a Dual P3 1Ghz and I get the same results with each 
> server.
>
> Ive tried a few recent 2.6 kernels but currently Im running kernel 
> 2.6.21.5.  The problem is that the performance of this set up is 
> incredibly poor.  Ive done some experimenting with the megaraid2 
> module params (Ive set cmd_per_lun=126 and max_sectors=1024 after 
> reading various forum posts) and managed to get the transfer rate up a

> bit but it still performs very badly.  I see some "reservation 
> conflict" and "unit not ready" messages when the megaraid2 module 
> loads which I am unsure of.
>
> After doing some googling I found someone saying that the megaraid2 
> driver in kernel 2.4.31 is the only version that they got any decent 
> performance out of the Dell PERC 4.  I tried kernel 2.4.31 and indeed 
> the performance is much more like what you would expect (only thing I
> have to go by is a windows box with a PERC 4 in it).   Ive tested both
> kernel 2.4.31 and 2.6.21.5 with our application, dd, bonnie and iozone

> on RAID 5 and RAID 1 arrays - kernel 2.4.31 performs better in each
> case.   The partitions are formatted as ext3 but Ive tried a few other
> filesystems such as XFS with various options and Im getting similar 
> differences between the results for each kernel.
>
> Heres an example comparison of bonnie benchmark results when using 
> kernel 2.4.31 and kernel 2.6.21.5, I used the following command; 
> bonnie -d ./ -s 512 -r 256 -x 5 -u 0 -g 0
>
>
> Kernel 2.4.31 / RAID 5
> ----------------------
> 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
> saasfs1        512M 11324  99 27539  27  6236   6  9113  67 42385  15
> 1392.7   4
>                     ------Sequential Create------ --------Random
> Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read---
> -Delete--
> files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> /sec %CP
> saasfs1          16   686  97 +++++ +++ +++++ +++   635  96 +++++ +++
> 2097  88
>
>
> Kernel 2.6.21.5 / RAID 5
> ------------------------
> 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
> saasfs1        512M 10357  64 10649  12  4957   5 11079  59 72623  39
> 1761.0   4
>                     ------Sequential Create------ --------Random
> Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read---
> -Delete--
> files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> /sec %CP
> saasfs1          16 19748  96 +++++ +++ 27202 100 20052  97 +++++ +++
> 26070  99
>
>
>
> Kernel 2.4.31 / RAID 1
> ----------------------
> 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
> saasfs1        512M 11303  99 44858  45 12319  10  8862  65 51459  17
> 2201.2   7
>                     ------Sequential Create------ --------Random
> Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read---
> -Delete--
> files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> /sec %CP
> saasfs1          16   631  96 +++++ +++ +++++ +++   621  94 +++++ +++
> 2349  97
>
>
> Kernel 2.6.21.5 / RAID 1
> ------------------------
> 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
> saasfs1        512M 15803  98 29338  34 10693  10 14016  75 95105  49
> 2172.1   5
>                     ------Sequential Create------ --------Random
> Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read---
> -Delete--
> files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> /sec %CP
> saasfs1          16   651  98 +++++ +++ +++++ +++   631  97 +++++ +++
> 2137  96
>
>
>
> I dont really want to have to stick with kernel 2.4.31 so if anyone 
> could shed some light on this issue it would be much appreciated.  
> Maybe Ive got the values Im passing into the module parameters 
> completely wrong or theres something else I need to tweak to get the 
> Dell PERC 4 to work better with the kernel 2.6 megaraid2 driver.
>
> Just below Ive put together the details of the scsi raid card and both

> kernels 2.4.31 and 2.6.21.5 (including kernel options, megaraid 
> version, modprobe command, relevent dmesg and lspci output).  Im 
> willing to do any testing if necessary.
>
> Thanks,
> Paul Bright.
>
>
>
> SCSI RAID
> ---------
> Card: Dell PERC4/DC
> Card firmware: 352B
> Card BIOS Ver: 1.10
> Card DRAM: 128MB
> Card Config:
>  - Cluster Mode: enabled (write cache off - there will be two machines

> connected to the JBOD)
>  - Emulation: mass storage
>  - SCSI transfer rate: 320M
>
> JBOD: Dell PowerVault 220S
> JBOD Firmware:  E19
>
> RAID Config for testing:
> /dev/sdb: RAID 5 - 3 Drives
> /dev/sdc: RAID 1 - 2 Drives
>
>
> --------------
> Kernel: 2.4.31
> --------------
> Kernel options: pci=noacpi
> Megaraid: v2.10.8.2 (Release Date: Mon Jul 26 12:15:51 EDT 2004) 
> modprobe command:  modprobe megaraid2 max_cmd_per_lun=126
> max_sectors_per_io=1024
>
>
> dmesg output
> ------------
> megaraid: v2.10.8.2 (Release Date: Mon Jul 26 12:15:51 EDT 2004)
> megaraid: found 0x1000:0x1960:bus 0:slot 11:func 0 scsi2:Found 
> MegaRAID controller at 0xe09d6000, IRQ:7
> megaraid: [352B:1.10] detected 2 logical drives.
> megaraid: supports extended CDBs.
> megaraid: channel[0] is raid.
> megaraid: channel[1] is raid.
> megaraid: Cluster driver, initiator id:7
> megaraid: no BIOS enabled.
> scsi2 : LSI Logic MegaRAID 352B 254 commands 16 targs 5 chans 7 luns
> scsi2: scanning scsi channel 0 for logical drives.
>   Vendor: MegaRAID  Model: LD 0 RAID5  139G  Rev: 352B
>   Type:   Direct-Access                      ANSI SCSI revision: 02
>   Vendor: MegaRAID  Model: LD 1 RAID1   69G  Rev: 352B
>   Type:   Direct-Access                      ANSI SCSI revision: 02
> scsi2: scanning scsi channel 1 for logical drives.
> scsi2: scanning scsi channel 2 for logical drives.
> scsi2: scanning scsi channel 3 for logical drives.
> scsi2: scanning scsi channel 4 [P0] for physical devices.
> scsi2: scanning scsi channel 5 [P1] for physical devices.
> Attached scsi disk sdb at scsi2, channel 0, id 0, lun 0 Attached scsi 
> disk sdc at scsi2, channel 0, id 1, lun 0
> scsi2 (0,0,0) : RESERVATION CONFLICT
> scsi2 (0,0,0) : RESERVATION CONFLICT
> scsi2 (0,0,0) : RESERVATION CONFLICT
> sdb: Unit Not Ready, error = 0x70018
> SCSI device sdb: 286228480 512-byte hdwr sectors (146549 MB)
>  /dev/scsi/host2/bus0/target0/lun0: p1
> scsi2 (0,1,0) : RESERVATION CONFLICT
> scsi2 (0,1,0) : RESERVATION CONFLICT
> scsi2 (0,1,0) : RESERVATION CONFLICT
> sdc: Unit Not Ready, error = 0x70018
> SCSI device sdc: 143114240 512-byte hdwr sectors (73274 MB)
>  /dev/scsi/host2/bus0/target1/lun0: p1
>
>
> lspci output
> ------------
> 0000:00:0b.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID 
> (rev 01)
>         Subsystem: Dell MegaRAID 518 DELL PERC 4/DC RAID Controller
>         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop-
> ParErr- Stepping- SERR+
>
> FastB2B-
>         Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=slow >TAbort-
> <TAbort- <MAbort-
>
> >SERR- <PERR-
>         Latency: 64, Cache Line Size: 0x08 (32 bytes)
>         Interrupt: pin A routed to IRQ 7
>         Region 0: Memory at f4110000 (32-bit, prefetchable) [size=64K]
>         Expansion ROM at <unassigned> [disabled] [size=64K]
>         Capabilities: [80] Power Management version 2
>                 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> PME(D0-,D1-,D2-,D3hot-,D3cold-)
>                 Status: D0 PME-Enable- DSel=0 DScale=0 PME-
>
>
>
> ----------------
> kernel: 2.6.21.5
> ----------------
> kernel options: acpi=off elevator=cfq
> megaraid cmm: 2.20.2.7 (Release Date: Sun Jul 16 00:01:03 EST 2006)
> megaraid: 2.20.5.1 (Release Date: Thu Nov 16 15:32:35 EST 2006) 
> modprobe command:  modprobe megaraid_mbox cmd_per_lun=126
> max_sectors=1024
>
>
> dmesg output
> ------------
> megaraid cmm: 2.20.2.7 (Release Date: Sun Jul 16 00:01:03 EST 2006)
> megaraid: 2.20.5.1 (Release Date: Thu Nov 16 15:32:35 EST 2006)
> megaraid: probe new device 0x1000:0x1960:0x1028:0x0518: bus 0:slot 
> 11:func 0
> megaraid: fw version:[352B] bios version:[1.10]
> megaraid: cluster firmware, initiator ID: 7
> scsi3 : LSI Logic MegaRAID driver
> scsi[3]: scanning scsi channel 0 [Phy 0] for non-raid devices
> scsi[3]: scanning scsi channel 1 [Phy 1] for non-raid devices
> scsi[3]: scanning scsi channel 2 [virtual] for logical drives
> scsi 3:2:0:0: Direct-Access     MegaRAID LD 0 RAID5  139G 352B PQ: 0
> ANSI: 2
> sd 3:2:0:0: reservation conflict
> sd 3:2:0:0: reservation conflict
> sd 3:2:0:0: reservation conflict
> sdb: Unit Not Ready, error = 0x70018
> SCSI device sdb: 286228480 512-byte hdwr sectors (146549 MB)
> sdb: Write Protect is off
> sdb: Mode Sense: 00 00 00 00
> sdb: asking for cache data failed
> sdb: assuming drive cache: write through sd 3:2:0:0: reservation 
> conflict sd 3:2:0:0: reservation conflict sd 3:2:0:0: reservation 
> conflict
> sdb: Unit Not Ready, error = 0x70018
> SCSI device sdb: 286228480 512-byte hdwr sectors (146549 MB)
> sdb: Write Protect is off
> sdb: Mode Sense: 00 00 00 00
> sdb: asking for cache data failed
> sdb: assuming drive cache: write through
>  sdb: sdb1
> sd 3:2:0:0: Attached scsi disk sdb
> sd 3:2:0:0: Attached scsi generic sg2 type 0
> scsi 3:2:1:0: Direct-Access     MegaRAID LD 1 RAID1   69G 352B PQ: 0
> ANSI: 2
> sd 3:2:1:0: reservation conflict
> sd 3:2:1:0: reservation conflict
> sd 3:2:1:0: reservation conflict
> sdc: Unit Not Ready, error = 0x70018
> SCSI device sdc: 143114240 512-byte hdwr sectors (73274 MB)
> sdc: Write Protect is off
> sdc: Mode Sense: 00 00 00 00
> sdc: asking for cache data failed
> sdc: assuming drive cache: write through sd 3:2:1:0: reservation 
> conflict sd 3:2:1:0: reservation conflict sd 3:2:1:0: reservation 
> conflict
> sdc: Unit Not Ready, error = 0x70018
> SCSI device sdc: 143114240 512-byte hdwr sectors (73274 MB)
> sdc: Write Protect is off
> sdc: Mode Sense: 00 00 00 00
> sdc: asking for cache data failed
> sdc: assuming drive cache: write through
>  sdc: sdc1
> sd 3:2:1:0: Attached scsi disk sdc
> sd 3:2:1:0: Attached scsi generic sg3 type 0
>
>
> lspci output
> ------------
> 00:0b.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID (rev
01)
>         Subsystem: Dell MegaRAID 518 DELL PERC 4/DC RAID Controller
>         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop-
> ParErr- Stepping- SERR+
>
> FastB2B-
>         Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=slow >TAbort-
> <TAbort- <MAbort-
>
> >SERR- <PERR-
>         Latency: 64, Cache Line Size: 32 bytes
>         Interrupt: pin A routed to IRQ 7
>         Region 0: Memory at f4110000 (32-bit, prefetchable) [size=64K]
>         [virtual] Expansion ROM at 30120000 [disabled] [size=64K]
>         Capabilities: [80] Power Management version 2
>                 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> PME(D0-,D1-,D2-,D3hot-,D3cold-)
>                 Status: D0 PME-Enable- DSel=0 DScale=0 PME-
>
>
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