creating a new 80 TB XFS

[Eric Sandeen]

On 10/1/12 9:28 AM, Richard Ems wrote:
> On 02/24/2012 04:17 PM, Eric Sandeen wrote:
>>> *MKFS*
>>>> We also heavily use ACLs for almost all of our files. Christoph Hellwig
>>>> suggested in a previous mail to use "-i size=512" on XFS creation, so my
>>>> mkfs.xfs would look something like:
>>>>
>>>> mkfs.xfs -i size=512 -d su=stripe_size,sw=28 -L Backup_2 /dev/sdX1
>> Be sure the stripe geometry matches the way the raid controller is
>> set up.
>>
>> You know the size of your acls, so you can probably do some testing
>> to find out how well 512-byte inodes keep ACLs in-line.
> 
> 
> Hi Eric,
> 
> This is a reply to an email from you sent 7 months ago ...
> 
> How could I do the testing you were proposing? How can I find out if my
> 512-byte inodes keep our ACLs in-line?
> 
> I am going to create a similar new RAID set, and wanted to check this
> before on the one already in production.

you can use the xfs_bmap tool to map the attribute fork by using the "-a" option.

If it lists any block numbers, then it's outside the inode.

If you have varying sizes of acls, you'd just iterate over the fs to see what you've got.

-Eric

> Thanks,
> Richard
>