pkgtrans/pkgadd extremely slow with 4mm tape on Solaris 2.5
slow reading from that tape. The answer appears to be that pkgtrans uses
horrible blocking choices. SO, don't use it. I've modified my procedures to tar
my packages to and from tape before using pkgadd to install them from their disk
copies. The performance improvement is huge... what used to take 45 - 90 minutes
is now taking 5 minutes for tape io.
Thanks to:
"Richard.Hellier" <rlh@cppuk.co.uk>
rloftin@engsys.mc.xerox.com (Ron Loftin)
Marc S. Gibian
Telos Consulting Services phone: (617) 377-6350
PRISM/TFS email:gibian@stars1.hanscom.af.mil
attached mail follows:
I am putting about 200meg of packages on a 4mm tape using the command:
pkgtrans /project/tfspkgs /dev/rmt/2hb TFScore TFShome TFSroot
On the target system, I am installing these packages using pkgadd, first copying
to a scratch area (since pkgadd tries to copy to an area in the root partition
when I try a direct install from tape) using:
pkgadd -d /dev/rmt/0 -s /export/home TFScore TFShome TFSroot
And then actually installing using an administration file that avoid prompting
and the command:
pkgadd -a <my-admin-file> -d /export/home TFScore TFShome TFSroot
The problem I am having is that writting the tape with pkgtrans is taking close
to an hour, reading the tape with pkgadd is taking almost exactly 45 minutes,
while the actual install is taking about 5 minutes.
I HAD written this off to the speed (or lack thereof ) of the 4mm drives (Sun
externals) until we ran some ufsdump/ufsrestore timings for something else and
came up with ufsdump of about 345meg in 10 minutes! There are some discrepencies
in our ufsrestore timings (345meg in 28 minutes, 173meg in 4 minutes... these
are too different), so I am not sure of the ufsrestore times we are seeing
relative to pkgadd's times, but it seems ufsrestore is still significantly
faster than pkgadd!
What is going on here?
What is the speed-optimal method for writting packages to tape and reading them
back? Since I am manually performing both operations, I will quickly toss
pkgtrans and pkgadd if there is something faster.
TIA,
Marc S. Gibian
Telos Consulting Services phone: (617) 377-6350
PRISM/TFS email:gibian@stars1.hanscom.af.mil
