Re: Maximum file system size of XFS?

Martin Steigerwald
2013-03-11T22:10:57Z

Am Montag, 11. März 2013 schrieb Martin Steigerwald:
> Am Samstag, 9. März 2013 schrieb Pascal:
> > Hello,
>
> Hi Pascal,
>
> > I am asking you because I am insecure about the correct answer and
> > different sources give me different numbers.
> >
> >
> >
> >
> > My question is: What is the maximum file system size of XFS?
> >
> >
> >
> > The official page says: 2^63 = 9 x 10^18 = 9 exabytes
> > Source: http://oss.sgi.com/projects/xfs/
> >
> >
> >
> > Wikipedia says 16 exabytes.
> > Source: https://en.wikipedia.org/wiki/XFS
> >
> >
> >
> > Another reference books says 8 exabytes (2^63).
> >
> >
> >
> >
> > Can anyone tell me and explain what is the maximum file system size for
> > XFS?
>
> You can test it. The theoretical limit. Whether such a filesystem will
> work nicely with a real workload is, as pointed out, a different
> question.

Well, as I just demonstrated, you can´t. At least not with XFS within XFS.
You can only test for maximum filesize. If XFS can be larger than that, you
need a filesystem which can carry an even larger file. Maybe ZFS on Linux or
so?

BTRFS doesn´t go beyond 8 EiB per file as well:

merkaba:/mnt#1> mkfs.btrfs -n 16384 -l 16384 /dev/merkaba/zeit

WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL
WARNING! - see http://btrfs.wiki.kernel.org before using

fs created label (null) on /dev/merkaba/zeit
nodesize 16384 leafsize 16384 sectorsize 4096 size 20.00GB
Btrfs Btrfs v0.19
merkaba:/mnt> mount /dev/merkaba/zeit zeit
merkaba:/mnt> cd zeit
merkaba:/mnt/zeit> truncate -s1E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s2E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s3E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s4E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s5E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s6E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s7E canitgetcrazierthanthat.img
merkaba:/mnt/zeit> truncate -s8E canitgetcrazierthanthat.img
truncate: ungültige Zahl „8E“: Der Wert ist zu groß für den definierten
Datentyp
merkaba:/mnt/zeit#1> LANG=C truncate -s8E canitgetcrazierthanthat.im
truncate: invalid number '8E': Value too large for defined data type

merkaba:/mnt/zeit#1> ls -lh
insgesamt 0
-rw-r--r-- 1 root root 7,0E Mär 11 23:09 canitgetcrazierthanthat.img

Thanks,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7