[Veritas-bu] HP Ultrium2 LTO II Drives Performance

Bhakat Amit Kumar(Amit) labsupport at iidc.lucent.com
Tue Mar 15 08:15:36 CST 2005

	Thanks to all who are all replayed. I have done the following changes in
/etc/system and Netbackup tune as per
http://seer.support.veritas.com/docs/183702.htm . Now I am gating 13Mb/s
throughput. But the drive can support 30Mb/s.
Also I observer the backup via Gige LAN is faster then local file system,
for local fs I am gating 5Mb/s. Where both the fs coming from same SAN

Can some one can tell me way to get best performance ?
Do I need to do any tune in File system label ?


-----Original Message-----
From: Dave Markham [mailto:dave.markham at fjserv.net]
Sent: Wednesday, March 09, 2005 8:39 PM
To: labsupport at iidc.lucent.com
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: Re: [Veritas-bu] HP Ultrium2 LTO II Drives Performance

labsupport is not your Lucent handle wrote:

>        I have installed a SUN L180 with 4 HP Ultrium2 drive (LTO2).
>Media and master server is SUN fire 6800 and having LVD SCSI.
>        I am backing up all the data using Gigabit Ethernet. I am gating
>10 MB/s throughput on a Gigabit lan with 4 drives.
>        Can any one tell what is the throughput  you are gating on LTO2
>        Do  I need to do any tune for OS or NB ? to get more performance.
Yes do the tuning. There is a guide

Also change the shared mem settings in /etc/system

* Message queues

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

* Semaphores

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

* Shared memory

set shmsys:shminfo_shmmax=16777216

set shmsys:shminfo_shmmin=1

set shmsys:shminfo_shmmni=220

set shmsys:shminfo_shmseg=100

These may have been updated

Im getting around 30 / 40 MB/s on my LTO2 sometimes peak at 70 according
to bptm logs. I am running over fibre to the drives though on an L700
and shared storage, but still you should be getting higher than 10


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