XFS In Dapper [previously posted to ubuntu-users]

[Nick Webb]

David Kempe wrote:
> XFS is good, we use it on dapper all the time. My largest XFS filesystem 
> is 5.5TB formatted.
> I have to say 64-bit is the only way to go for this - the xfs repair 
> tools can't handle larger filesystems in 32bit mode.
> btw, one thing I found was that xfs_repair can chew massive amounts of 
> ram to run a repair on a filesystem. I had a 2TB fs take nearly 8gb of 
> ram (and swap) to repair it. It did a good job of repairing, and took 
> ages. So XFS is not free of the fsck problem, just xfs_check is faster 
> and perhaps less thorough (dunno).


I'll be doing all of these on 64-bit systems, good to know.  I just got 
a new project today that will start out around 5TB and likely grow to 7 
or 8 soon.  Not all these systems have enough ram + swap to get to 8GB 
of virtual memory, I wonder how it works without that much, I hope it 
doesn't just fail?

Also, you can run xfs_check online, right?  That's my impression, so at 
least the server isn't down during the check, although it will likely be 
crawling.

> 
> Importantly, you can have data-loss on XFS if you lose power suddenly, 
> perhaps more so than ext3. When files get corrupted on XFS, I have 
> noticed they go to zero size, whereas in messy situations with ext3 I 
> have noticed you are more likely to loose metadata than data. I still 
> would stick with XFS anyday though, even just because the sheer increase 
> in format time.

Yes I've heard this as well from some RedHat/CentOS friends.  My intent 
would be to make sure all the systems with XFS have a good UPS, and are 
setup to shutdown on power loss.  Of course, we'll have a good backup 
plan as well.  That should mitigate things to the point it doesn't 
really matter...

> 
> I have had good results on many different types of block devices as well.
> 
> thanks
> 
> dave

Thanks much Dave, I'm feeling more confident already.



-- 
Nick Webb
System Administrator
Freelock Computing - www.freelock.com
206.577.0540 x22