Difference between revisions of "2019 June"

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(June 01)
(June 04)
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== June 04 ==
 
== June 04 ==
 
'''15:05 UT''' More on the storage issue.  Looking at tape backup, one can purchase a HP Ultrium tape drive for about $1600, with 1.5/3 TB cartridges costing $25 each.  I also find an 80 GB Stonefly rackmount storage system costs about $7000 (with 8 x 10 TB drives).  The latter could store up to 3.5 years of data at our current rate (or 2 years in addition to our current database).  We really need to have one unit at OVRO and a second one at NJIT.  We could solve our current problem, then, by spending $2600 on tape backup (for long-term storage) plus $365/year going forward, and $14,000 for dual-capacity storage.  Total for the next two years: $17,500.  This is certainly a good investment!  In two years, there may be other storage options.
 
'''15:05 UT''' More on the storage issue.  Looking at tape backup, one can purchase a HP Ultrium tape drive for about $1600, with 1.5/3 TB cartridges costing $25 each.  I also find an 80 GB Stonefly rackmount storage system costs about $7000 (with 8 x 10 TB drives).  The latter could store up to 3.5 years of data at our current rate (or 2 years in addition to our current database).  We really need to have one unit at OVRO and a second one at NJIT.  We could solve our current problem, then, by spending $2600 on tape backup (for long-term storage) plus $365/year going forward, and $14,000 for dual-capacity storage.  Total for the next two years: $17,500.  This is certainly a good investment!  In two years, there may be other storage options.
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== June 19 ==
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'''23:09 UT''' Just a note to say that I (--[[User:Dgary|Dgary]] ([[User talk:Dgary|talk]]) 23:11, 19 June 2019 (UTC)) am at OVRO this week and will be messing with the system.  Today is a good example--several calibrations, correlator restart, setting of delays, etc., have pretty much messed up today's data.  I am chasing a long-standing problem with low signal levels at high frequencies, and will also be working on improving total power calibration.

Revision as of 23:11, 19 June 2019

Back to Observing Log

June 01

12:18 UT Just a note to say the data archive disk is getting full, so we need to stage some data off. One option is to move data prior to 2017 off. Here are the data usages by year:

  • 2014 (0.3 TB)
  • 2015 (1 TB)
  • 2016 (9.5 TB)
  • 2017 (6 TB)
  • 2018 (5.4 TB)
  • 2019 (5.4 TB)

Note that 2019 is less than half over, so we are looking at more than 10 TB/year (actually should be more than 20 TB/year by my calculation of 60 GB/day).

June 04

15:05 UT More on the storage issue. Looking at tape backup, one can purchase a HP Ultrium tape drive for about $1600, with 1.5/3 TB cartridges costing $25 each. I also find an 80 GB Stonefly rackmount storage system costs about $7000 (with 8 x 10 TB drives). The latter could store up to 3.5 years of data at our current rate (or 2 years in addition to our current database). We really need to have one unit at OVRO and a second one at NJIT. We could solve our current problem, then, by spending $2600 on tape backup (for long-term storage) plus $365/year going forward, and $14,000 for dual-capacity storage. Total for the next two years: $17,500. This is certainly a good investment! In two years, there may be other storage options.

June 19

23:09 UT Just a note to say that I (--Dgary (talk) 23:11, 19 June 2019 (UTC)) am at OVRO this week and will be messing with the system. Today is a good example--several calibrations, correlator restart, setting of delays, etc., have pretty much messed up today's data. I am chasing a long-standing problem with low signal levels at high frequencies, and will also be working on improving total power calibration.