Re: mksnap_ffs takes 4-5 minutes?

Thomas E. Zander wrote:
> Hi,
> 
> On Tue, 19. Jul 2005, at 15:38 -0500, Eric Anderson wrote
> according to [mksnap_ffs takes 4-5 minutes?]:
> 
> 
>>This time, when I ran mksnap_ffs, the command took nearly 5 minutes
> 
> 
> [...]
> 
> 
>>Filesystem        1K-blocks     Used     Avail Capacity iused    ifree 
>>/dev/da1s1d       406234604 91799154 281936682    25% 1300303 51197103 
> 
> 
> I have a fs here with similar (but smaller size) parameters concerning
> inode density and usage:
> 
> Filesystem  1K-blocks     Used    Avail Capacity iused    ifree
> /dev/ad1s1d 113390248 92926924 18195520    84%  248434 14424460
> 
> time mksnap_ffs'ing gives the following result:
> 0.007u 1.902s 1:51.94 1.6%      5+217k 4493+8646io 0pf+0w
> 
> It takes almost 2 minutes which seem to perform similarly to your 5
> minutes.
> (There was not a single file opened when snapping.)
> 
> I'd expect snapping to speed up by reducing the inode number when doing
> newfs, but I haven't verified this right now.

A 2tb filesystem with the standard newfs options takes about 30 minutes 
to mksnap..  That's unusable really, because the filesystem is suspended 
for so long.  Even empty 2tb filesystems take forever, so it's related 
to the amount of inodes.

How can we make this snappier?

Eric


-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
A lost ounce of gold may be found, a lost moment of time never.
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