Commands Queued Output

[Patrick_Boyd at Dell.com]

I'm not really sure if there is anyway to zero it out. I'll look at it.
What you might want to do is exclude the proc and sys directories from
your backup. It's possible that a read to a node in one of these
directories is trying to send a command to your enclosure.

Patrick Boyd
Dell Storage Software Engineer
(512)728-3182


-----Original Message-----
From: Randall Smith [mailto:randall at tnr.cc] 
Sent: Tuesday, October 03, 2006 4:12 PM
To: Boyd, Patrick
Cc: linux-poweredge-Lists
Subject: Re: Commands Queued Output

Thanks Patrick.

I started a log using cron to capture the state of proc/scsi/aic7xxx/0
daily.  I found that the "commands queued" number is jumping during the
tape backup, which tars the root directory.  Does that give you some
idea of what is happening?  And how can I set the commands queued back
to zero to prevent a crash?

Randall

Patrick_Boyd at Dell.com wrote:
> Target 6 should be the enclosure or backplane. As far as why the 
> commands are being queued to it, it might just be that something is 
> trying to send SCSI pass throughs or IO that the enclosure doesn't 
> understand.
> 
> Patrick Boyd
> Dell Storage Software Engineer
> (512)728-3182
>  
> 
> -----Original Message-----
> From: linux-poweredge-bounces at dell.com 
> [mailto:linux-poweredge-bounces at dell.com] On Behalf Of Randall Smith
> Sent: Thursday, September 21, 2006 12:06 PM
> To: linux-poweredge-Lists
> Subject: Commands Queued Output
> 
> Sorry if this dups.  I didn't send in my confirmation in time, so the 
> first attempt got rejected.
> 
> The following is a message I sent a while back to a list that no 
> longer exists.  The server discussed here crashed this morning with a 
> kernel panic and after a reboot the commands queued on Target 6 stands
at 2.
> The machine is a PowerEdge 2500 running Debian Sarge.  I don't know 
> for sure this is what caused the crash, but I'd like to understand it 
> regardless.  Any insight into what the Target 6 information means and 
> why it has a huge queue would be greatly appreciated.
> 
> Thanks.  -Randall
> 
> cat /proc/scsi/aic7xxx/0
> 
> is producing this output
> 
> ---snip---
> Target 5 Negotiation Settings
>          User: 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit)

> Target 6 Negotiation Settings
>          User: 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit)
>          Goal: 80.000MB/s transfers (40.000MHz, offset 32, 16bit)
>          Curr: 80.000MB/s transfers (40.000MHz, offset 32, 16bit)
>          Channel A Target 6 Lun 0 Settings
>                  Commands Queued 26151289
>                  Commands Active 0
>                  Command Openings 1
>                  Max Tagged Openings 0
>                  Device Queue Frozen Count 0
> ---snip---
> 
> and I'm concerned because I don't know what it means.  I have a two 
> disk mirrored array setup.  I don't know what Target 6 is and why it 
> has commands queued or even what that means.  I'm guessing it isn't a 
> good thing.  Any help is appreciated.
> 
> --Randall
> 
> output of afacli:
> 
> AFA0> container list
> Executing: container list
> Num          Total  Oth Chunk          Scsi   Partition
> Label Type   Size   Ctr Size   Usage   B:ID:L Offset:Size
> ----- ------ ------ --- ------ ------- ------ -------------
>   0    Mirror 33.8GB            Valid   0:00:0 64.0KB:33.8GB
>   /dev/sda             MIRROR_DWS       0:01:0 64.0KB:33.8GB
> 
> AFA0> disk list
> Executing: disk list
> 
> B:ID:L  Device Type     Blocks    Bytes/Block Usage            Shared
> Rate
> ------  --------------  --------- ----------- ---------------- ------
> ----
> 0:00:0   Disk            71132959  512         Initialized      NO
> 160
> 0:01:0   Disk            71132959  512         Initialized      NO
> 160
> 
> AFA0> disk show smart /all
> Executing: disk show smart /all=TRUE
> 
>          Smart    Method of         Enable
>          Capable  Informational     Exception  Performance  Error
> B:ID:L  Device   Exceptions(MRIE)  Control    Enabled      Count
> ------  -------  ----------------  ---------  -----------  ------
> 0:00:0     Y            6             Y           N             0
> 0:01:0     Y            6             Y           N             0
> 
> AFA0> disk show defects 0
> Executing: disk show defects (ID=0)
> 
> Number of PRIMARY defects on drive: 978
> 
> Number of GROWN defects on drive: 0
> 
> AFA0> disk show defects 1
> Executing: disk show defects (ID=1)
> 
> Number of PRIMARY defects on drive: 112
> 
> Number of GROWN defects on drive: 0
> 
> 
> result of lspci is
> 
> 0000:01:02.1 RAID bus controller: Dell PowerEdge Expandable RAID 
> Controller 3/Di (rev 01) 0000:02:04.0 SCSI storage controller: Adaptec

> RAID subsystem HBA (rev 01)
> 0000:02:04.1 SCSI storage controller: Adaptec AIC-7899P U160/m (rev 
> 01) 0000:03:06.0 SCSI storage controller: Adaptec AHA-3960D / 
> AIC-7899A U160/m (rev 01)
> 0000:03:06.1 SCSI storage controller: Adaptec AHA-3960D / AIC-7899A 
> U160/m (rev 01)
> 
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