STACKER NOTE Stac Electronics Technical Note Subject: Scheck and Stacker space reporting Tech011 - 2/20/92 Page 1 OF 1 _
Stacker's SCHECK utility offers information on the physical and logical Stacker drive regarding total, used, and remaining bytes; percentage of space used and free; compression ratio and projected bytes free. Below is a typical SCHECK report:
SCHECK - 2.0, © Copyright 1990-92 Stac Electronics, Carlsbad, CA Volume in drive E is STACVOL_DSK No errors found Stacker Drive Statistics:
Stacker Drive STACVOL File
Drive E: E:\STACVOL.DSK
---------------------- ----------------------
Total Bytes: 4,096,000 2,054,656
Bytes Used: 3,735,552 ( 91.2%) 1,846,272 ( 89.9%)
Bytes Free: 360,448 ( 8.8%) 208,384 ( 10.1%)
Stacker Drive Compression Ratio = 2.0:1 Projected Bytes Free = 360,448
What does it all mean?
The left hand column displays logical data on the Stacker drive. This is how DOS and CHKDSK see the drive. The right hand column shows the usage of space (physical) inside the STACVOL file. This is the file that contains all of your compressed data. Its name and location are shown in the column title.
Compression ratio: The Stacker drive compression ratio is the average compression ratio of the files in that specific STACKER drive. In the above example, the 2.0:1 ratio tells us that the files in this Stacker drive are taking up half the space they would take up on non "Stacked" drive. The drive compression ratio does not display if the drive is empty.
Projected bytes free: This number is Stacker's estimate of the available space left on the drive. If the drive is less than 12% full, or if the drive compression ratio is 2.0:1 or greater, this number will be the same as bytes free in the Stacker drive (left column). The projected bytes free on drives with usage over 12%, or compression ratios less than 2.0:1, will be a number slightly less than the bytes free in the STACVOL file multiplied by the overall compression ratio.