SUMMARY: Missing gigabytes?

From: Patrick McCormick <pmccormi_at_MIT.EDU>
Date: Mon, 15 Jun 1998 18:46:04 -0400

Patrick McCormick wrote:
> I just added a Seagate ST118273LW (Barracuda 18G) drive to an AlphaStation
> 500. The installation went fine, and the drive was detected and labeled
> with no problem. We want to use the whole drive for data, so we newfs'd
> partition c. Disklabel says this about partition c:
>
> c: 35566480 0 4.2BSD 1024 8192 16 # (Cyl. 0 -
> 7503*)
>
> df -k says this about the mountpoint:
>
> Filesystem 1024-blocks Used Available Capacity Mounted on
> /dev/rz1c 17254184 1 15528764 1% /ext
>
> Now, the 17G number is what I expected, but the 15.5G number is far lower
> than I had hoped. Where did the 1.7 GB's go? I suspect that maybe UFS
> can't handle such a large partition or needs a lot of accounting space.
> Please let me know if you have a good answer to this.

It turns out that UFS was reserving 10% of the disk for overflow (as it
always does) and that 10% was a huge chunk of my disk. I used:

tunefs -m 1 /dev/rz1c

to change it to 1%, and at tunefs' behest:

tunefs -o space /dev/rz1c

to change the allocation strategy to value space over time.

If anyone has advice as to whether this is a bad way to partition the disk
due to some weird UFS-ism, please let me know.

Thanks to:

Gyula Szokoly
Ian Mortimer
Jim Williams

for their advice.

--Pat McCormick
Received on Tue Jun 16 1998 - 00:46:57 NZST

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:37 NZDT