Using xfs_growfs on SSD raid-10

[Alexey Zilber]

Hi All,

  I've read the FAQ on 'How to calculate the correct sunit,swidth values
for optimal performance' when setting up xfs on a RAID.  Thing is, I'm
using LVM, and with the colo company we use, the easiest thing I've found,
when adding more space, is to have another RAID added to the system, then
I'll just pvcreate, expand the vgroup over it, lvextend and xfs_growfs and
I'm done.  That is probably sub-optimal on an SSD raid.

Here's the example situation.  I start off with a 6 (400GB) raid-10.  It's
got 1M stripe sizes.  So I would start with pvcreate --dataalignment 1M
/dev/sdb
after all the lvm stuff I would do: mkfs.xfs -L mysql -d su=1m,sw=3
/dev/mapper/db-mysql
(so the above reflects the 3 active drives, and 1m stripe. So far so good?)

Now, I need more space. We have a second raid-10 added, that's 4 (400gb)
drives. So I do the same pvcreate --dataalignment 1M /dev/sdc
then vgextend and lvextend, and finally; with xfs_growfs, there's no way to
specify, change su/sw values.  So how do I do this?  I'd rather not use
mount options, but is that the only way, and would that work?

Thanks!
Alexey
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://oss.sgi.com/pipermail/xfs/attachments/20130110/f79629b3/attachment.htm>