Bacula-users

Re: [Bacula-users] LTO-7 tape drive settings in bacula 7.4.0

2016-05-26 14:17:11
Subject: Re: [Bacula-users] LTO-7 tape drive settings in bacula 7.4.0
From: "Rao, Uthra R. (GSFC-672.0)[ADNET SYSTEMS INC]" <uthra.r.rao AT nasa DOT gov>
To: Kern Sibbald <kern AT sibbald DOT com>, "bacula-users AT lists.sourceforge DOT net" <bacula-users AT lists.sourceforge DOT net>
Date: Thu, 26 May 2016 18:16:02 +0000

Thank you all for taking the time to reply to my email.

 

We are using LTO-7 tapes with the LTO-7 Tape drives. I don’t think the data transfer rate is an issue in our case. I am thinking of removing the “MaxBlocksize” and “Maximum Network Buffer Size” I have currently set for the tape drives so that it will use the defaults. I will then run a test backup to see if this helps.

 

Regards,

Uthra

 

 

From: Kern Sibbald [mailto:kern AT sibbald DOT com]
Sent: Thursday, May 26, 2016 7:56 AM
To: Rao, Uthra R. (GSFC-672.0)[ADNET SYSTEMS INC]; bacula-users AT lists.sourceforge DOT net
Subject: Re: [Bacula-users] LTO-7 tape drive settings in bacula 7.4.0

 

Hello,


The tape probably got an error.  You should be able to see if there were problems by looking at dmesg output and Bacula output for the job that marked the tape full.

The error, if there was one, is very likely coming from the fact that you set the block size too big.  I believe that anything more than 512K will probably not improve performance much but it will increase significantly the chances of a write error.

Try running some tests with 512K max block size and see if the tape fills up correctly.

Best regards,
Kern



On 25/05/2016 20:04, Rao, Uthra R. (GSFC-672.0)[ADNET SYSTEMS INC] wrote:

I have a Qualstar Tapeell library (RLS-87120) with three LTO7 tape drives.  It is connected to the backup server directly through Fiber Channel. I am  running bacula 7.4.  I ran a test backup which completed successfully but I found that the LTO-7 Tape was not used up to its full capacity of 6TB. It wrote 2.6TB and marked the tape “FULL” then moved on to the next tape in the pool. I expected the backup to write 6TB to the tape before marking it “FULL”? Here is the information from my bacula-sd.conf:

 

  Maximum File Size = 50G

  Maximum Network Buffer Size = 65536

 Maximum Block Size = 2097152

 

The MaxBlock: 8388608 is seen in the tapeinfo command on the tape drive0:

 

   # tapeinfo -f /dev/tapedr0

Product Type: Tape Drive

Vendor ID: 'IBM     '

Product ID: 'ULTRIUM-HH7     '

Revision: 'FA11'

Attached Changer API: No

SerialNumber: '10WT004131'

MinBlock: 1

MaxBlock: 8388608

SCSI ID: 0

SCSI LUN: 0

Ready: yes

BufferedMode: yes

Medium Type: 0x78

Density Code: 0x5c

BlockSize: 0

DataCompEnabled: yes

DataCompCapable: yes

DataDeCompEnabled: yes

CompType: 0xff

DeCompType: 0xff

BOP: yes

Block Position: 0

Partition 0 Remaining Kbytes: -1

Partition 0 Size in Kbytes: -1

ActivePartition: 0

EarlyWarningSize: 0

NumPartitions: 0

MaxPartitions: 3

 

I am not sure if the issue I am seeing with the tape not being used to its full capacity is due to the “Max Block size” I have set? What is the recommended setting for LTO-7? If anybody could share your knowledge about this I would really appreciate it. I did some search on the internet and could not find any useful information.

 

Thank you




------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j




_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users

 

------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j
_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users