What are the disks? With ATA disks, you can't perform reads and writes at
the same time. You should always try and stage at a different time of the
day than backups.
Hope that helps
Siobhan
On 12/3/07 6:15 PM, "Yaron Zabary" <yaron AT ARISTO.TAU.AC DOT IL> wrote:
> Hello all,
>
> Recently, we purchased a Dell/EMC AX150SC storage for the disk backup
> option. We have some performance problems with it which are described in
> the letter below (which I sent to my Dell/EMC support). Does anyone have
> a similar setup and can tell if they see similar problems or were able
> to get decent performance from this machine ?
>
>
>
> -------- Original Message --------
> Subject: AX150 performance problems.
> Date: Mon, 05 Mar 2007 12:24:05 +0200
> From: Yaron Zabary <yaron AT aristo.tau.ac DOT il>
> To: michaelz AT bynet.co DOT il
>
> Hello,
>
> I have performance problems with the AX150SC we have. These are the
> details:
>
> . The AX150 is connected to a single Sun 280R server via an Emulex HBA
>
> . The Server is a Sun 280R with two 750Mhz CPUs and 2Gb RAM running
> Solaris 9 (SunOS legato.tau.ac.il 5.9 Generic_118558-39 sun4u sparc
> SUNW,Sun-Fire-280R). I applied all patches required by EMC for Solaris
> 9. The server also has four LTO2 drives connected to another dual-LVD HBA
>
> . The HBA is Emulex 9802 running the latest firmware (1.91a5) with
> driver 6.10g. The HBA shares the 33Mhz PCI bus with a GigE card. The LVD
> HBA has its own 66Mhz PCI bus.
>
> . The AX150SC has 12 500Gb disks. Its Flare was upgraded to
> 02.20.150.5.022. All disks are in a single pool with a single hot spare.
> Currently, there are two 2Tb LUNs defined (due to Solaris 2Tb
> limitations). Only the first LUN is in use. Event log is empty. All
> components are green on the view/component screen.
>
> . /etc/system has the following lines (as required by EMC):
>
> set sd:sd_max_throttle=20
> set sd:sd_io_time=0x3c
> set ssd:ssd_max_throttle=20
> set ssd:ssd_io_time=0x3c
>
> . The backup software we use is EMC Networker version 7.2.2 build
> 422. Networker uses the first LUN for disk bacckup (using advfile
> device). The backups are then staged (copied) to the LTO2 drives.
>
> . The problem starts when the server tries to stage savesets from the
> disk while running backups. During such operations the read speed can be
> as low as 500Kb/s. Write speed also drops from ~25Mb/s to ~10Mb/s. While
> this happens 'sar -d' reports a huge number for average wait time for
> I/O requests (over 1.5 seconds per request). Also notice the huge queue
> (over 300 requests) and the large service time (~100msec). The numbers
> below are 10 minutes averages:
>
> sd60 99 306.6 190 11077 1508.4 101.0
> sd60,a 99 306.6 190 11077 1508.4 101.0
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 350.0 187 10387 1769.8 106.1
> sd60,a 100 350.0 187 10387 1769.8 106.1
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 348.3 194 10767 1690.5 102.0
> sd60,a 100 348.3 194 10767 1690.5 102.0
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 311.7 199 13024 1470.7 99.0
> sd60,a 100 311.7 199 13024 1470.7 99.0
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 364.3 209 10714 1644.8 94.9
> sd60,a 100 364.3 209 10714 1644.8 94.9
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 375.6 193 10093 1840.4 103.0
> sd60,a 100 375.6 193 10093 1840.4 103.0
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 346.1 197 11119 1653.3 100.4
> sd60,a 100 346.1 197 11119 1653.3 100.4
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 341.2 197 11666 1628.1 100.5
> sd60,a 100 341.2 197 11666 1628.1 100.5
> sd60,h 0 0.0 0 0 0.0 0.0
> sd60 100 339.6 196 11948 1629.5 100.8
> sd60,a 100 339.6 196 11948 1629.5 100.8
> sd60,h 0 0.0 0 0 0.0 0.0
>
>
> Please advice.
>
> --
>
> -- Yaron.
>
Siobhán
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