Backup Central

Amanda users,

We are running our amanda server on Solaris 10 x86 with a
fiber connection to an SL24/LTO4 library.

Comparing this to another amanda server, same amanda and
OS versions, same jukebox/drive, we see only about 20-25%
of the tape write speed (as reported by amdump) using the
fiber connection as we do with a SCSI connection.

Sorry - lots of words.
SCSI connection runs 4-5x faster than fiber connection.

Following the suggestion found here
http://forums.zmanda.com/showthread.php?t=1250

Try setting
device_property "BLOCK_SIZE" "2 mbytes"
in the top-level of amanda.conf on the system with the fiber
connection, left the faster scsi connected server alone.

I found that # amcheck was unable to find any valid tapes
in the existing tape pool.

amcheck -t curie
Amanda Tape Server Host Check
-----------------------------
slot 13:Found an empty or non-amanda tape.
slot 14:Found an empty or non-amanda tape.
slot 15:Found an empty or non-amanda tape.
slot 16:Found an empty or non-amanda tape.
slot 17:Found an empty or non-amanda tape.
slot 18:Found an empty or non-amanda tape.
slot 19:Found an empty or non-amanda tape.
slot 20:Found an empty or non-amanda tape.
slot 21:Found an empty or non-amanda tape.
slot 22:Found an empty or non-amanda tape.

Is the advice not valid for our config ?
Do we need to re-label tapes if we set this parameter ?

thanks,

Brian

---
Brian R Cuttler brian.cuttler < at > wadsworth.org
Computer Systems Support (v) 518 486-1697
Wadsworth Center (f) 518 473-6384
NYS Department of Health Help Desk 518 473-0773



IMPORTANT NOTICE: This e-mail and any attachments may contain
confidential or sensitive information which is, or may be, legally
privileged or otherwise protected by law from further disclosure. It
is intended only for the addressee. If you received this in error or
from someone who was not authorized to send it to you, please do not
distribute, copy or use it or any attachments. Please notify the
sender immediately by reply e-mail and delete this from your
system. Thank you for your cooperation.

Dustin,

Updated amanda.conf with
device_property "BLOCK_SIZE" "2 mbytes"

Tried to relabel a labeled but never used tape, priviously
Curie46, labeled with the default device_property (default
as in I hadn't specified anything).

I have to overwrite the tape header, there is a level below
the amanda label I have to get to ?

Device is an LTO4 imbedded in an SL24 library fiber connected
to a x4500 Solaris 10x86 box.

amlabel -f curie Curie47 slot 23
labeling tape in slot 23 (/dev/rmt/0n):
Reading label...
Found an empty tape.
Writing label Curie47..
amlabel: Error writing label: Error writing tapestart header: I/O error.

thank you,

Brian

On Fri, Mar 05, 2010 at 05:54:40PM -0600, Dustin Mitchell wrote:
On Mar 5, 2010, at 12:25 PM, Brian Cuttler <brian < at > wadsworth.org> wrote:

Is the advice not valid for our config ?
Do we need to re-label tapes if we set this parameter ?

The advice is valid, but yes you will need to relabel the tapes.

Dustin
---
Brian R Cuttler brian.cuttler < at > wadsworth.org
Computer Systems Support (v) 518 486-1697
Wadsworth Center (f) 518 473-6384
NYS Department of Health Help Desk 518 473-0773



IMPORTANT NOTICE: This e-mail and any attachments may contain
confidential or sensitive information which is, or may be, legally
privileged or otherwise protected by law from further disclosure. It
is intended only for the addressee. If you received this in error or
from someone who was not authorized to send it to you, please do not
distribute, copy or use it or any attachments. Please notify the
sender immediately by reply e-mail and delete this from your
system. Thank you for your cooperation.

Dustin,

Ivan at my site nailed it.

Mar 8 12:59:37 curie scsi: [ID 107833 kern.warning] WARNING:
/pci < at > 3,0/pci1022,7458 < at > 9/pci1000,1020 < at > 1/fp < at > 0,0/tape < at > w500110a0008b3fda,0 (st0):
Mar 8 12:59:37 curie Cannot alloc contig buf for I/O for 2097152 blk size

setting the block_size to 1 meg took.
device_property "BLOCK_SIZE" "1 mbytes"

Waiting on amcheck to complete, then we will allow a test run
this evening to see if we have any better I/O to the tape.

On Mon, Mar 08, 2010 at 12:47:43PM -0600, Dustin J. Mitchell wrote:
On Mon, Mar 8, 2010 at 12:43 PM, Brian Cuttler <brian < at > wadsworth.org> wrote:
I have to overwrite the tape header, there is a level below
the amanda label I have to get to ?

I don't actually know the answer to that one. You may need to degauss the tape?

Dustin

--
Open Source Storage Engineer
http://www.zmanda.com
---
Brian R Cuttler brian.cuttler < at > wadsworth.org
Computer Systems Support (v) 518 486-1697
Wadsworth Center (f) 518 473-6384
NYS Department of Health Help Desk 518 473-0773



IMPORTANT NOTICE: This e-mail and any attachments may contain
confidential or sensitive information which is, or may be, legally
privileged or otherwise protected by law from further disclosure. It
is intended only for the addressee. If you received this in error or
from someone who was not authorized to send it to you, please do not
distribute, copy or use it or any attachments. Please notify the
sender immediately by reply e-mail and delete this from your
system. Thank you for your cooperation.