5 ms·

The lab I work in at NASA Goddard is doing the detector characterization for WFIRST. There are 18, 4k × 4K detectors in the WFIRST array, for a resolution of ab

The lab I work in at NASA Goddard is doing the detector characterization for WFIRST. There are 18, 4k × 4K detectors in the WFIRST array, for a resolution of about 300 megapixels, as mentioned in the article. The detectors are arranged in an unusual pattern, but I don't know what drove that design. I am, at this moment, working on a new fileserver that will be used for WFIRST detector test data. It will start off with a RAID array of just under 1PB and will likely be expanded as we proceed with testing. I'm hoping this thing launches before I retire, but I'm not betting on it. JWST keeps eating our budget.

traskjd 8y ago
Quietly hoping you’re about 64 years old.
- rootbear 8y ago
  Just 61-1/2! But I may not wait until my official retirement age of 66-1/2, which I'll reach at the end of 2023. I don't seriously believe that WFIRST will launch before then anyway. I'm not even sure our other major project, Euclid (an ESA telescope) will launch before I'm retired, and it's much further along.
zepearl 8y ago
Any infos about the RAID itself? (e.g. disks, raid type, software managing the raid, OS it is running on, client protocols being used, which decisions/priorities resulted in the current setup, etc...) I love such details :P
- rootbear 8y ago
  It's nothing really exotic. It's a "high density" storage system from RAID, Inc., with 84 drives in a 5U form factor. We got 12TB drives, so raw capacity is 1008TB. It's connected to a Dell R640 server running CentOS 7. I'll configure it with RAID 6, with a some hot spares. I'll also buy a few cold spares. The file systems on it will be shared via NFS to various client systems. We have a rack of compute servers for data analysis which are connected to the file servers through a 10Gbit switch.
  - flyinglizard 8y ago
    Just wondering - why RAID6 and not ZFS?
    - rootbear 8y ago
      I don't have a lot of experience with ZFS and I've been reluctant to use it on Linux, due to the licensing issues. But I am interested in ZFS and will probably look into it at some point. I'd probably need a different storage solution, one that presents all the drives individually to the host, since that's what ZFS wants.
      - ianai 8y ago
        Any chance at bringing someone new in to take over the brunt of the design and implementation? It sounds like a natural point to transition.
        deleted 8y ago
        [deleted]
      - mirimir 8y ago
        Isn't RAID6 iffy re bit rot at PB levels?
      - jakeogh 8y ago
        Cool project! ZoL is rock solid and it's easy to setup. You could switch it over in a weekend. The standard HBA last time I bought one was the M1015 flashed into IT mode. ZFS data integrity features alone are worth it for that much data. If you mention what you are up to on freenode#zfsonlinux people will jump at the opportunity to help.
jerf 8y ago
Sometimes I really love the 21st century. "Yeah, we're starting with a petabyte... it's not really enough, it won't last that long, but it'll get us started, at least. I've already started on the purchase orders for the next three petabytes...."

traskjd 8y ago

Quietly hoping you’re about 64 years old.

rootbear 8y ago
Just 61-1/2! But I may not wait until my official retirement age of 66-1/2, which I'll reach at the end of 2023. I don't seriously believe that WFIRST will launch before then anyway. I'm not even sure our other major project, Euclid (an ESA telescope) will launch before I'm retired, and it's much further along.

zepearl 8y ago

Any infos about the RAID itself? (e.g. disks, raid type, software managing the raid, OS it is running on, client protocols being used, which decisions/priorities resulted in the current setup, etc...) I love such details :P

rootbear 8y ago
It's nothing really exotic. It's a "high density" storage system from RAID, Inc., with 84 drives in a 5U form factor. We got 12TB drives, so raw capacity is 1008TB. It's connected to a Dell R640 server running CentOS 7. I'll configure it with RAID 6, with a some hot spares. I'll also buy a few cold spares. The file systems on it will be shared via NFS to various client systems. We have a rack of compute servers for data analysis which are connected to the file servers through a 10Gbit switch.
- flyinglizard 8y ago
  Just wondering - why RAID6 and not ZFS?
  - rootbear 8y ago
    I don't have a lot of experience with ZFS and I've been reluctant to use it on Linux, due to the licensing issues. But I am interested in ZFS and will probably look into it at some point. I'd probably need a different storage solution, one that presents all the drives individually to the host, since that's what ZFS wants.
    - ianai 8y ago
      Any chance at bringing someone new in to take over the brunt of the design and implementation? It sounds like a natural point to transition.
      - deleted 8y ago
        [deleted]
    - mirimir 8y ago
      Isn't RAID6 iffy re bit rot at PB levels?
    - jakeogh 8y ago
      Cool project! ZoL is rock solid and it's easy to setup. You could switch it over in a weekend. The standard HBA last time I bought one was the M1015 flashed into IT mode. ZFS data integrity features alone are worth it for that much data. If you mention what you are up to on freenode#zfsonlinux people will jump at the opportunity to help.

jerf 8y ago

Sometimes I really love the 21st century. "Yeah, we're starting with a petabyte... it's not really enough, it won't last that long, but it'll get us started, at least. I've already started on the purchase orders for the next three petabytes...."