[Gluster-users] iowait - ext4 + ssd journal

[Joshua Baker-LePain]

On Mon, 3 Nov 2014 at 5:37pm, Lindsay Mathieson wrote

> On 4 November 2014 11:28, Paul Robert Marino <prmarino1 at gmail.com> wrote:
>> Use XFS instead of EXT4
>> There are many very good reasons its the new default filesystem in RHEL 7
>
> xfs can't use a external journal.

Actually, it can.  I remember playing with it *way* back in the day when 
XFS was first ported to Linux.  From 'man mkfs.xfs':

        The  metadata  log can be placed on another device to reduce the number
        of disk seeks.  To create a filesystem on the first  partition  on  the
        first  SCSI  disk with a 10000 block log located on the first partition
        on the second SCSI disk, use:

               mkfs.xfs -l logdev=/dev/sdb1,size=10000b /dev/sda1


-- 
Joshua Baker-LePain
QB3 Shared Cluster Sysadmin
UCSF