WP7161: Dan, Dave:

Following Dan's suggestion, the SATABOY units have been split into two non-equal parts. The first is a small QFS file system (written by CDS, read by LDAS), which will hold the framed files' MD5 check sum files*. The second is a larger ZFS file system to hold the archived raw minute trend files (written and read by CDS).

The reason for the split is to perform firmware data compression, using the ZFS compression utility, for the archived raw minute trend files. Dan has found that GZIP-LEVEL5 compression gives us the 'best bang for our buck' in terms of compression ratio and cpu loading. We are expecting a compression ration of around 7.

Once the past 6 months of archived raw minute trend data have been copied, I'll reconfigure h1nds1 to serve these data.

In Detail: the SATABOY has 12 2TB HDD. They are allocated thusly:

* - writing the MD5 files to this location requires a daqd code change, I have submitted ECR-E1700382