gnu@hoptoad.uucp (John Gilmore) (11/18/86)
I too had an odd experience with dump/restore recently, on a Sun-3/160
running Sun Unix 3.0.
I was getting a variety of errors on one of my SCSI 71 meg disks
containing /usr/spool, and decided to reformat it. I also wanted to
reduce the number of inodes in /usr/spool -- I overrode the default
formula to provide more inodes for the large number of short files
(news articles). Turns out that I never got above 5 or 10% inode
usage, and I wanted to reclaim some of that space. I run this
partition at 4K blocks, 512 byte frags to reduce wasted space.
I took the system down to single user, ran fsck on the partition, did
an incremental dump of it (I had a fulldump, also done single user,
from a month before), reformatted it, did a new mkfs on it (being less
generous with inodes), and did a restore of the full dump and
incremental dumps. The restore ran really incredibly slowly -- many
hours to restore a partition that took 25 minutes to dump. It
complained about two or three missing files (individual articles in
/usr/spool/news) but I kept telling it to continue doing its best. It
completed successfully, and I had about 10 megs more free space due to
fewer inodes.
* Why did restore complain about a few files, when the dumps were
both taken on quiescent, fsck'd file systems?
--
John Gilmore {sun,ptsfa,lll-crg,ihnp4}!hoptoad!gnu jgilmore@lll-crg.arpa
"I can't think of a better way for the War Dept to spend money than to
subsidize the education of teenage system hackers by creating the Arpanet."matt@oddjob.UUCP (Matt Crawford) (11/21/86)
John Gilmore asks the burning question: > > * Why did restore complain about a few files, when the dumps were > both taken on quiescent, fsck'd file systems? Fsck doesn't read the data blocks, so those may have had errors which caused dump to skip them. I also have noticed that it takes semi-infinite time to do an incremental restore. Why *is* this so? Was the dump/restore system optimized to speed up the more common dump at the expense of the less common restore operation? _____________________________________________________ Matt University crawford@anl-mcs.arpa Crawford of Chicago ihnp4!oddjob!matt ..If I had heart failure right now, I couldn't be a more fortunate man!!