Maximum file system size of XFS?

[Martin Steigerwald]

Am Montag, 11. März 2013 schrieb Martin Steigerwald:
> Am Montag, 11. März 2013 schrieb Martin Steigerwald:
> > 2) Create a insanely big sparse file
> > 
> > merkaba:~> truncate -s1E /mnt/zeit/evenmorecrazy.img
> > merkaba:~> ls -lh /mnt/zeit/evenmorecrazy.img
> > -rw-r--r-- 1 root root 1,0E Mär 11 22:37 /mnt/zeit/evenmorecrazy.img
> > 
> > (No, this won´t work with Ext4.)
> 
> Okay, you can´t go beyond 8 EiB for a single file which is about what I
> have read somewhere:
[…]
> merkaba:/mnt/zeit> truncate -s7E /mnt/zeit/evenmorecrazy.img
> merkaba:/mnt/zeit> LANG=C truncate -s8E /mnt/zeit/evenmorecrazy.img
> 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 22:49 evenmorecrazy.img
> 
> So so tests stops there, until you concatenate two of those files with
> LVM or SoftRAID 0 (if that works). Like this (I just had to try it):
> 
> 
> merkaba:/mnt/zeit> ls -lh
> insgesamt 0
> -rw-r--r-- 1 root root 7,0E Mär 11 22:49 evenmorecrazy.img
> -rw-r--r-- 1 root root 7,0E Mär 11 22:52 evenmorecrazy.img2
> merkaba:/mnt/zeit> losetup /dev/loop0 evenmorecrazy.img
> merkaba:/mnt/zeit> losetup /dev/loop1 evenmorecrazy.img2
> 
> merkaba:/mnt/zeit#5> pvcreate /dev/loop0
>   Physical volume "/dev/loop0" successfully created
> merkaba:/mnt/zeit> pvcreate /dev/loop1
>   Physical volume "/dev/loop1" successfully created
> merkaba:/mnt/zeit> vgcreate justinsane /dev/loop0 /dev/loop1
>   PV /dev/loop0 too large for extent size 4,00 MiB.
>   Format-specific setup of physical volume '/dev/loop0' failed.
>   Unable to add physical volume '/dev/loop0' to volume group
> 'justinsane'.
[…]
> merkaba:/mnt/zeit#5> vgcreate --physicalextentsize 4G  justinsane
> /dev/loop0 /dev/loop1
>   Volume group "justinsane" successfully created
> 
> merkaba:/mnt/zeit> vgs
>   VG         #PV #LV #SN Attr   VSize   VFree
>   justinsane   2   0   0 wz--n-  14,00e 14,00e
>   merkaba      1   4   0 wz--n- 278,99g  4,85g
> merkaba:/mnt/zeit>
> 
> merkaba:/mnt/zeit> vgdisplay justinsane
[…]
> Enough insanity for today :)

Not quite:

> I won´t mkfs.xfs on it, the 20 GiB of the just filesystem wouldn´t be
> enough.

Ok, there seems to be another limit involved:

merkaba:/mnt/zeit> lvcreate -n yourbiggiexfs -L14E justinsane
  Volume group "justinsane" has insufficient free space (3758096382 
extents): 3758096384 required.
merkaba:/mnt/zeit#5> LANG=C lvcreate -n yourbiggiexfs -L14E justinsane
  Volume group "justinsane" has insufficient free space (3758096382 
extents): 3758096384 required.
merkaba:/mnt/zeit#5> LANG=C lvcreate -n yourbiggiexfs -L13E justinsane
  /dev/justinsane/yourbiggiexfs: lseek 0 failed: Invalid argument
  /dev/justinsane/yourbiggiexfs: lseek 0 failed: Invalid argument
  Logical volume "yourbiggiexfs" created
merkaba:/mnt/zeit> LANG=C lvs                                       
  /dev/justinsane/yourbiggiexfs: lseek 14987979559888945152 failed: Invalid 
argument
  /dev/justinsane/yourbiggiexfs: lseek 14987979559889002496 failed: Invalid 
argument
  /dev/justinsane/yourbiggiexfs: lseek 0 failed: Invalid argument
  /dev/justinsane/yourbiggiexfs: lseek 4096 failed: Invalid argument
  /dev/justinsane/yourbiggiexfs: lseek 0 failed: Invalid argument
  LV            VG         Attr      LSize   Pool Origin Data%  Move Log 
Copy%  Convert
  yourbiggiexfs justinsane -wi-a----  13.00e 

So testing with 9 EiB might become some issue :)

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