MSS Efficiency Data

Tier-0 Site Last Update
CERN MssEfficiencyCERN 20081201
Tier-1 Sites Data Available
CA-TRIUMF MssEfficiencyCA-TRIUMF 20080623
DE-KIT MssEfficiencyDE-KIT 20080615
ES-PIC MssEfficiencyES-PIC 20080614
FR-CCIN2P3 MssEfficiencyFR-CCIN2P3 -
IT-INFN-CNAF MssEfficiencyIT-INFN-CNAF 20080617
NDGF MssEfficiencyNDGF 20080609
NL-T1 MssEfficiencyNL-T1 20080623
TW-ASGC MssEfficiencyTW-ASGC -
UK-T1-RAL MssEfficiencyUK-T1-RAL 20081101
US-FNAL-CMS MssEfficiencyUS-FNAL-CMS 20090629
US-T1-BNL MssEfficiencyUS-T1-BNL 20081822

Explanation of Metrics for MSS Efficiency

1. Total Rate - The total volume of data transferred divided by the number of seconds that a drive is occupied serving the request. This includes mounting and positioning time, data transfer time and unmounting time. It is expressed in MB/s.

2. File Size - The average file size in MB transferred to or from the tape drive. The performance of tape drives varies according to the file size. The larger the file size, the higher the drive performance since it is able to achieve full data streaming. Smaller file sizes require the drive to stop/start more frequently, reducing performance as well as increasing wear and tear on the drives and tapes.

3. Tape Repeat Mounting - The remounting metrics track the average number of times a tape is mounted for all of the tapes which were touched that day. When the migration and recalling strategies are working well, this should be a low number. A tape mount and positioning takes between 3 and 5 minutes and the tape drive is not being used for data transfer during this period so a large number of repeat mounting wastes potential data transfer time. For example, if 10 tapes were touched in that day. One of the tapes were mounted 5 times and the rest only once, the total mounts were: 9 + 5 = 14. So the answer is 14/10 = 1.4. So Tape Repeat Mounting is 1.4.

4. Data Transferred / Mount - The volume of data in MB transferred on average for mounts during the day. Higher values indicate that the work for mounting is being effectively used.

Site / Experiment

Date 1. Total Data Rate 2. Avg. File Size 3. Tape Repeat Mnt 4. Data xferred/mnt
  Read Write Read Write Read Write Read Write
20080202 x x x x x x x x
20080209 x x x x x x x x
Topic attachments
I Attachment History Action Size Date Who Comment
XMLxml CA_TRIUMF_Tape_Metrics.xml r3 r2 r1 manage 1.9 K 2009-05-12 - 13:41 AlbertoAimar  
XMLxml CERN_Tape_Metrics.xml r4 r3 r2 r1 manage 14.4 K 2009-05-28 - 17:29 AlbertoAimar  
XMLxml DE_KIT_Tape_Metrics.xml r7 r6 r5 r4 r3 manage 3.4 K 2009-05-28 - 10:51 AlbertoAimar  
XMLxml ES_PIC_Tape_Metrics.xml r2 r1 manage 1.9 K 2009-05-12 - 13:42 AlbertoAimar  
XMLxml FR_CCIN2P3_Tape_Metrics.xml r2 r1 manage 1.9 K 2009-05-12 - 13:42 AlbertoAimar  
XMLxml IT_INFN_CNAF_Tape_Metrics.xml r2 r1 manage 1.9 K 2009-05-12 - 13:42 AlbertoAimar  
XMLxml NDGF_Tape_Metrics.xml r2 r1 manage 1.8 K 2009-05-12 - 13:42 AlbertoAimar  
XMLxml NL_T1_Tape_Metrics.xml r3 r2 r1 manage 1.8 K 2009-05-12 - 13:53 AlbertoAimar  
XMLxml TW_ASGC_Tape_Metrics.xml r1 manage 1.9 K 2009-05-12 - 13:43 AlbertoAimar  
XMLxml UK_T1_RAL_Tape_Metrics.xml r2 r1 manage 1.9 K 2009-05-12 - 13:43 AlbertoAimar  
XMLxml US_FNAL_CMS_Tape_Metrics.xml r2 r1 manage 1.9 K 2009-05-12 - 13:43 AlbertoAimar  
XMLxml US_T1_BNL_Tape_Metrics.xml r6 r5 r4 r3 r2 manage 1.9 K 2009-05-12 - 13:43 AlbertoAimar  
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Topic revision: r88 - 2009-06-29 - JonBakken
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