Snapshot ufs blocking

[Eric Anderson]

Since there's been some chatter about snapshots recently, I thought I'd 
give more snapshots a try along with some quick tests. 

I've recently updated my server to 6.1-PRERELEASE (as of yesterday), and 
am running happily.

Now, for the snapshot information. 

While creating a snapshot (on a rather large 2tb volume that is 94% 
used), using:

mksnap_ffs /vol1 /vol1/.snap/2006-03-10.snap

I can move around /vol1, ls, df, etc.  I can cd to /vol1/.snap/, and do 
an ls, and the snapshot continues just fine.  However, as soon as I do a 
ls -al against the /vol1/.snap/2006-03-10.snap file (in this case, my 
cwd is /vol1/.snap/ and I do an ls -al), the ls blocks on ufs, and then 
subsequent ls -al's of the root (/), the partition (/vol1/), all block 
in 'ufs'.  Also, once this has happened, my mksnap_ffs stops, also 
blocked in 'ufs', and my ls's don't return (I've only waited about 20 
minutes though).  I could see the stat on the snapshot file itself 
blocking, but the rest of the system shouldn't block, should it?


Eric


-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
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