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From: p v <pvlogin@yahoo.com>
To: xfs@oss.sgi.com
Subject: file preallocation without unwritten flag being set
Date: Tue, 12 May 2009 16:02:05 -0700 (PDT)	[thread overview]
Message-ID: <283244.29270.qm@web65608.mail.ac4.yahoo.com> (raw)



Hello,

I need to create large files fast without initializing them - in the past I used these steps -

mkfs -t xfs -f -d unwritten=0 /dev/sda1
mount -t xfs -o noatime /dev/sda1 /hay
touch /hay/foo
xfs_io /hay/foo
xfs_io> resvsp 0 1024g
xfs_io> quit
ls -i /hay/foo
131 /hay/foo
umount /hay
xfs_db -x /dev/sda1
xfs_db> inode 131
xfs_db> write core.size 1099511627776
core.size = 1099511627776
xfs_db> q

But unwritten=0 is failing as unrecognized option now (was it deprecated????) so I tried to clear the unwritten extent flag directly -

xfs_db> a u.bmbt.ptrs[1]
xfs_db> write recs[1].extentflag 0
recs[1].extentflag = 1
xfs_db> 

It just won't change to 0 - any way to do this? Or is there any straightforward way to preallocate a large file and set it's file size without the unwritten flags being turned on?

Thanks

Peter Vajgel



      

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             reply	other threads:[~2009-05-12 23:02 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-12 23:02 p v [this message]
2009-05-13  0:04 ` file preallocation without unwritten flag being set Eric Sandeen
2009-05-13  4:34   ` p v
2009-05-13  5:08     ` Eric Sandeen
2009-05-13 21:05       ` p v
2009-05-13 21:48         ` Eric Sandeen
2009-05-13 22:28         ` Dave Chinner
2009-05-13 23:51           ` p v
2009-05-14  0:17             ` Eric Sandeen
2009-05-14  0:34               ` Dave Chinner
2009-05-14  0:41                 ` Eric Sandeen

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