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Re: Optimal XFS formatting options?

To: xfs@xxxxxxxxxxx
Subject: Re: Optimal XFS formatting options?
From: MikeJeezy <forums@xxxxxxxxxxxx>
Date: Sun, 15 Jan 2012 16:27:23 -0800 (PST)
In-reply-to: <4F12006F.8080805@xxxxxxxxxxxxxxxxx>
References: <33140169.post@xxxxxxxxxxxxxxx> <4F12006F.8080805@xxxxxxxxxxxxxxxxx>
>So let's assume your vendor does the smart thing and allows you 
>flexibility in specifying per drive strip size.  Assume for example the 
>stripe unit (strip, chunk) of the array is 64KB, there are 10 stripe 
>spindles (12-2=10), and the local device name of the LUN is /dev/sdb. 
>To create an aligned XFS filesystem on this you would use something like: 

>$ mkfs.xfs -d su=64k sw=10 /dev/sdb 

Great explanations! (some of it I am still trying to understand :-)  In this
case on my HP P2000 G3, I do have a 64k chunk size so I will do:

$ mkfs.xfs -d su=64k,sw=10 /dev/sdd

Question: Does the above command assume I do not already have a partition
created?  I was 
http://www.fhgfs.com/wiki/wikka.php?wakka=PartitionAlignment reading here 
that the easiest way to acheive partition alignment is to create the file
system directly on the storage device without any paritions - such as $
mkfs.xfs /dev/sdd  (and your example above also hints at this)

When I created my current partiton, I used the following commands:

$ parted -a optimal /dev/sdd
$ mklabel gpt
$ mkpart primary 0 -0
$ q

I would like to align the partiton as well, but I am not sure how to acheive
this using parted.  This will be the only partition on the LUN, so not sure
if I even need to create one (although I do like to stay consistent with my
other volumes). 

When printing the partition info with parted I see:

# (parted) p                                                                
Model: HP P2000 G3 iSCSI (scsi)
Disk /dev/sdd: 4900GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name     Flags
 1      1049kB  4900GB  4900GB  xfs          primary

but from reading, I suspect the Sector size should be more like: 
(logical/physical): 512B/65536B.  Any thoughts on partition alignment or
other thoughts in general?  Thank you.

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