Re: Storage server
Am Freitag, 14. September 2012 schrieb Stan Hoeppner:
> On 9/14/2012 7:57 AM, Martin Steigerwald wrote:
> > Am Freitag, 14. September 2012 schrieb Stan Hoeppner:
> >> Thus my advice to you is:
> >>
> >> Do not use LVM. Directly format the RAID10 device using the
> >> mkfs.xfs defaults. mkfs.xfs will read the md configuration and
> >> automatically align the filesystem to the stripe width.
> >
> >
> >
> > Just for completeness:
> >
> >
> > It is possible to manually align XFS via mkfs.xfs / mount options.
> > But then thats an extra step thats unnecessary when creating XFS
> > directly on MD.
>
> And not optimal for XFS beginners. But the main reason for avoiding
> LVM is that LVM creates a "slice and dice" mentality among its users,
> and many become too liberal with the carving knife, ending up with a
> filesystem made of sometimes a dozen LVM slivers. Then XFS
> performance suffers due to the resulting inode/extent/free space
> layout.
Agreed.
I have seen VMs with seperate /usr and minimal / and mis-estimated sizing.
There was perfectly enough place in the VMDK, but just in the wrong
partition. I fixed it back then by adding another VMDK file. (So even with
partitions I found those setups.)
Something else is to split up /var/log or /var.
But then we are talking about user and not system data here anyway.
I have always recommended to leave at least 10-15% free, but from a
discussion on XFS mailinglist where you took part, I learned that
depending on use case for large volumes even more free space might be
necessary for performant long term operation.
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7
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