Coda File System

Re: Problems with tar archives

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Sun, 7 Oct 2001 03:39:51 -0400
On Thu, Oct 04, 2001 at 11:52:43PM +0200, Matthias Teege wrote:
> I hope this isn't an FAQ but I have an problem with tar archives
> on coda filesystems. I made an archiv via tar -czf
> /coda/archiv.tar.gz /dir and if I try to do tar -xzf
> /coda/archiv.tar.gz I get an tar: can't open archive
> archiv.tar.gz: No space left on device, tar: child returned
> status 3.

Actually this is a FAQ, the untar very quickly creates many files.
When creating the many directories the server slows down and as a
result clients assume this is due to network congestion and back off
quite agressively by switching to write-disconnected operation.

In write-disconnected operation all modifications are logged in the CML
and kept for approximately 5 to 10 minutes during which log-optimization
might get rid of operations. However there isn't much to optimize and
the tar as fast enough to fill the finite log on the client before
reintegration takes place. Once the log is full, clients will report
ENOSPC to applications that try to store anything more.

The only way around this is to either slow down the creation of new
files (cp is slower than tar), force the client to ignore network
measurements that make it switch to write-disconnected operation (by
running 'cfs strong'), or by having a larger client-cache which also
increases the size of the CML.

Jan
Received on 2001-10-07 03:41:41