MBR: unaligned? GPT: 4K-aligned? Different disks show different results?

[justinkas]

I was curious about the Default partition format settings under disk settings. Honestly I've never set anything in here and the default shows currently as MBR: unaligned. About a week ago I cleared my entire unraid server and changes all of my disks over to XFS format. I didn't even thing to make any changed to this setting.

 

Should my default setting in disk settings be: MBR: unaligned OR GPT: 4K-aligned?

 

Currently my WD 1tb & 2tb older data drives are showing up as MBR: unaligned, my newer 4tb drives are showing up as 4k-aligned and my parity 4tb drive is showing up as 4k-aligned.

 

Does this seem to be correct for my system or do I need to change my older 1tb drives to 4k-aligned? I'm not messing with this now until I hear back as I wasn't sure if this was anything important or not. Also, can these older drives showing up as MBR: unaligned be changes to 4k-aligned without erasing the data (formatting etc.) on them? What does the 4k-aligned setting actually do as far as improvement etc.?

[betaman]

Bumping this one as I have the exact same issue/question.  In particular, should I be attempting to change my drives from unaligned to aligned where applicable?

[itimpi]

For disks above 2TB in size I think they will always end up as 4k aligned and GPT partitions.

 

As to changing this on smaller disks, I am reasonably certain it cannot be done without wiping the existing contents so is probably not something you want to do on an existing system.  I think the purpose of the setting with the older disks was to do with improving performance for some drives.

[betaman]

For disks above 2TB in size I think they will always end up as 4k aligned and GPT partitions.

 

As to changing this on smaller disks, I am reasonably certain it cannot be done without wiping the existing contents so is probably not something you want to do on an existing system.  I think the purpose of the setting with the older disks was to do with improving performance for some drives.

 

Well, I'm in the middle of switching from reiserfs to xfs due to some issues transferring larger files to my unRAID server.  If I was ever going to do it, now would be the time since I'm converting 12 disks over.  I assume this will become an option in the disk settings page if it's applicable?  So far, I've only converted disks that were already 4k-aligned.  There wasn't an option to switch to unaligned as the whole configuration was greyed out.