I'm doing amvault from disk to tape the workload on the server is the same no 
shortage of memory cpu resources.
Xfer rate to tape reduced by 60% from version 3.2.0 to 3.3.7 !

-----Ursprungligt meddelande-----
Från: [email protected] [mailto:[email protected]] För 
Jean-Francois Malouin
Skickat: den 3 september 2015 21:37
Till: [email protected]
Ämne: Re: Tape write rate much slower efter upgrade

Hi, 


* Jean-Louis Martineau <[email protected]> [20150903 15:21]:
> Gunnar,
> 
> Do the number by DLE always differ?
> Are you using a holding disk?
> Can you monitor the server to find some bottleneck, memory, cpu, 
> network, disk I/O, ...

I witnessed the same behaviour back in February when upgrading from
3.3.5 to 3.3.7. I tried to post to the list a few times but somehow my posts 
never made it, maybe because they had 2 pics attached showing the performance 
from the hold disk to the tape drive. Here's what I wrote back then:

"2 weeks ago I upgraded one of my amanda server from 3.3.5 to 3.3.7.
Right away I noticed a ~25% tape write performance degradation to a LTO4 tape 
drive. I've attached 2 pics showing the xfer IO rate to/from the
holddisk: one shows a snapshot of the week after the upgrade with the 10th of 
Feb still at 3.3.5 (and a xfer rate of ~100MBs) and a drop to ~75MBs after the 
upgrade was done.  I reverted back to 3.3.5 a few days ago and the 2nd snapshot 
shows a return to previous rate."

HTH,
jf

> 
> Jean-Louis
> 
> On 03/09/15 02:49 PM, Gunnarsson, Gunnar wrote:
> >
> >Hi,
> >
> >See below slow down in avg tp write rate after having upgraded amanda 
> >from 3.2.0 to 3.3.7p1 nothing else is changed.
> >
> >We are using DLT drivers SCSI and fiber connected.
> >
> >Thanks Gunnar
> >
> >Tape Time (hrs:min) 2:37       2:37       0:00
> >
> >Tape Size (meg) 382968.9   382968.9        0.0
> >
> >Tape Used (%) 324.1      324.1        0.0
> >
> >DLEs Taped 462        462          0
> >
> >Parts Taped 462        462          0
> >
> >Avg Tp Write Rate (k/s) 41670.4    41670.4        --
> >
> >(brought to you by Amanda version 3.2.0)
> >
> >Tape Time (hrs:min) 4:18       4:18       0:00
> >
> >Tape Size (meg) 384525.8   384525.8        0.0
> >
> >Tape Used (%) 334.0      334.0        0.0
> >
> >DLEs Taped 481        481          0
> >
> >Parts Taped 481        481          0
> >
> >Avg Tp Write Rate (k/s) 25469.2    25469.2        --
> >
> >(brought to you by Amanda version 3.3.7p1)
> >
> >Tape Time (hrs:min) 6:03       1:46       4:18
> >
> >Tape Size (meg) 710405.4   208727.0   501678.5
> >
> >Tape Used (%) 161.0       47.4      113.6
> >
> >DLEs Taped 12          4          8  1:7 2:1
> >
> >Parts Taped 27          8         19  1:11 2:8
> >
> >Avg Tp Write Rate (k/s) 33357.3    33701.7    33216.0
> >
> >USAGE BY TAPE:
> >
> >  Label Time         Size      %  DLEs Parts
> >
> >  Orabck-Unix-002 3:37      431135M   92.5    11    19
> >
> >  Orabck-Unix-003 2:25      279270M   59.9     1     8
> >
> >(brought to you by Amanda version 3.3.7p1)
> >
> >Tape Time (hrs:min) 3:13       0:11       3:01
> >
> >Tape Size (meg) 776730.9    50668.0   726062.8
> >
> >Tape Used (%) 177.9       12.6      165.3
> >
> >DLEs Taped 18          4         14  1:9 2:5
> >
> >Parts Taped 33          4         29  1:11 2:18
> >
> >Avg Tp Write Rate (k/s) 68857.4    77438.9    68329.0
> >
> >USAGE BY TAPE:
> >
> >  Label Time         Size      %  DLEs Parts
> >
> >  Orabck-Unix-015     1:34 392152M   84.2     4    12
> >
> >  Orabck-Unix-016     1:34 384579M   82.5    14    21
> >
> >(brought to you by Amanda version 3.2.0)
> >
> 

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