PD001
1 Copper

Backing up SAN LUN

We have a Model 70-0120 PS4000, we have one LUN connected through our Ethernet NIC on a Dell 2850 for our user and group shares. While backing up the shares, it stops halfway through and my server becomes unavailable and needs a reboot. I am looking through the events and in the PS4000 and see that the target went offline. We are backing up @500GB of data and I'm try to determine if I am overloading the NIC on the server causing the outage

 

thanks

Pat

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4 Replies

Re: Backing up SAN LUN

Are you backing up a snapshot? or the original volume?   If the snapshot runs out of reserve it will be deleted.  If you are not backing up a snapshot and the VOLUME is going offline open a case with support.  They'll need diags from the array.

What are you using for a switch?   Backups are sustained reads,  a common issue is that the switch isn't up to iSCSI spec and/or flowcontrol isn't enabled and which causes the connection to get dropped because of retransmit timeout errors.

-doln

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evilensky
2 Iron

Re: Backing up SAN LUN

Hello,

When you say the target has gone offline, do you mean its status is "Offline" in CLI/Group Manager GUI?

Or is it an "offline volume" as reported by the machine's Disk Management MMC snap-in?

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PD001
1 Copper

Re: Backing up SAN LUN

The Target meaning the Windows 2003 Server the LUN is connected to, Backing up the LUN with a Backup Exec Agent, I looked through the Events and found the following on the server

Event Type:        Error

Event Source:    EqualLogic

Event Category:                VSS

Event ID:              4002

Date:                     7/25/2011

Time:                    5:19:35 AM

User:                     N/A

Computer:          WIHDFPS01

Description:

Error 0x80070490 opening SNMP connection to \\.\PHYSICALDRIVE2 (0-8a0906-d811f1407-ac2000cfa8b4c2db).

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Moderator
Moderator

Re: Backing up SAN LUN

PD001,

Review the connection configuration starting at the dedicated iSCSI interface on the server, then the iSCSI switch global and port settings.  These settings should be optimized for iSCSI.  We have several documents on the support site that discusses how to do this.  A good starting point is the Configuration Guide (http://dell.to/bE5fBd) and the Group Administration Guide (available on the Firmware Download page – use the guide that matches the version of firmware currently running on the array).

Regarding the iSCSI network:

Ensure you have the latest drivers and firmware on the LAN and iSCSI interfaces hosted by this server (and are properly configured in the advanced settings).

Ensure you have the latest firmware on your switches.

Ensure you have setup a separate VLAN on the switch just for iSCSI traffic.

Ensure the switch is setup properly for iSCSI.

Regarding the array:

Ensure you have the latest FW version installed.

Check the event log for anything unusual (i.e., unable to communicate to host during the backup time).

(Optional) setup a syslog server to capture all the events from the array, this makes monitoring the array easier, then having to use the GUI event log.

As Don suggested, if you have reviewed all of this and feel the SAN network is properly setup, then open a support case.

Regards,

Joe

-Joe

Social Media and Community Professional
#IWork4Dell
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Follow me on Twitter: @joesatdell 

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