Veritas-bu

[Veritas-bu] Linux Shared Memory Configuration

2006-09-21 14:31:35
Subject: [Veritas-bu] Linux Shared Memory Configuration
From: kfhemness at ucdavis.edu (Kathryn Hemness)
Date: Thu, 21 Sep 2006 11:31:35 -0700 (PDT)
Greetings,

I made the kernel parameter changes and they had no impact, so
I decided to take a closer look at the errors.

All of the errors were for backups and backup duplications of a single
Windows client.  I've been troubleshooting EXIT 14 backup failures on
this client since May without any luck.

For some reason, this client's EXIT 14 failures started leaving 1K
disk buffer files on my media server storage unit in early September.
My backup image duplication script does not check the validity of
the backupid for files left in the disk storage unit path, so it
attempts to duplicate a non-existent backupid.

I've not yet compared my pre-change bptm/bpdm logs to see if the
changes made any difference in empty buffer delays.

---------- Forwarded message ----------
Date: Tue, 19 Sep 2006 11:09:40 -0700 (PDT)
From: Kathryn Hemness <cckat at mailbox.ucdavis.edu>
To: "Nardello, John" <john.nardello at wamu.net>
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: RE: [Veritas-bu] Linux Shared Memory Configuration

Greetings,

Thanks to all who responded....Most of the suggestions were helpful.

This is a good technote and I'm going to try adjusting my values.
Regarding bob944's comments, my Linux media servers ARE running
with default kernel parameters and I'm seeing shared memory errors.
The files in the /usr/openv/netbackup/db/config were recommended
for both Solaris and Linux.  It is for these reasons that I posted
my query.

I'm posting my current values for the parameters and indicating
the recommended minimal settings in parenthesis:

kernel.msgmnb = 16384 (65536)
kernel.msgmni = 16    (256)
kernel.msgmax = 8192  (8192)


kernel.shmmni = 4096     (1024)
kernel.shmall = 2097152  (nothing indicated in document)
kernel.shmmax = 33554432 (16777216) - my value is already larger, so I'm 
keeping it.


kernel.sem = 250        32000   32      128
            (300         1024   32      1024)
           semmsl,     semmns, semopm, semmni)

My Linux servers have 4GB of memory so I can always make upward adjustments.



On Tue, 19 Sep 2006, Nardello, John wrote:

> Date: Tue, 19 Sep 2006 08:21:59 -0700
> From: "Nardello, John" <john.nardello at wamu.net>
> To: Kathryn Hemness <kfhemness at ucdavis.edu>,
>      veritas-bu at mailman.eng.auburn.edu
> Subject: RE: [Veritas-bu] Linux Shared Memory Configuration
>
> Technote talking about Linux kernel tuning recommendations:
> http://support.veritas.com/docs/263755
>
> A little old but I doubt the variables have changed any.
>
> - John Nardello
>
> -----Original Message-----
> From: veritas-bu-bounces at mailman.eng.auburn.edu
> [mailto:veritas-bu-bounces at mailman.eng.auburn.edu] On Behalf Of Kathryn
> Hemness
> Sent: Monday, September 18, 2006 3:59 PM
> To: veritas-bu at mailman.eng.auburn.edu
> Subject: [Veritas-bu] Linux Shared Memory Configuration
>
> Greetings,
>
> My backup enterprise currently consists of a Solaris 9 Sun V240 master
> and 3 Sun X4200 RHEL3 Linux Media Servers running NB51MP5.
>
> I've been getting the following messages for backups and duplications
> to storage units on my Linux media servers:
>
>    "problems encountered during setup of shared memory (89)"
>
> I use disk storage units and a mixed LTO2/LTO3 library.
>
> I've attempted to setup my Linux media servers similar to my Solaris 9
> master by using the same NUMBER/SIZE_DATA_BUFFERS files in
> /usr/openv/netbackup/db/config.  But on my Solaris 9 master, I also
> had /etc/system settings for msgsys, semsys, and shmsys values.
>
> I haven't been able to find anything about needing similar
> /etc/system tuning on Linux (I believe the /etc/system equivalents are
> set
> via the /etc/sysctl.conf file).
>
> I'm hoping someone can tell me if all of the /etc/system parameters can
> be set with sysctl on Linux and if their names are the same.  Here are
> my
> current Solaris /etc/system parameters:
>
> set msgsys:msginfo_msgmap=512
> set msgsys:msginfo_msgmax=8192
> set msgsys:msginfo_msgmnb=65536
> set msgsys:msginfo_msgmni=256
> set msgsys:msginfo_msgssz=16
> set msgsys:msginfo_msgtql=512
> set msgsys:msginfo_msgseg=8192
>
> set semsys:seminfo_semmap=64
> set semsys:seminfo_semmni=1024
> set semsys:seminfo_semmns=1024
> set semsys:seminfo_semmnu=1024
> set semsys:seminfo_semmsl=300
> set semsys:seminfo_semopm=32
> set semsys:seminfo_semume=64
>
> set shmsys:shminfo_shmmax=536870912
> set shmsys:shminfo_shmmin=1
> set shmsys:shminfo_shmmni=220
> set shmsys:shminfo_shmseg=100
>
> Any help is appreciated.
> --Kathy
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--Kathy