[SOLVED] Should I reformat these drive as 4k?

[savestheday]

Hi all,

Running the latest 5.0 beta (need AFP). Still learning the ropes with unRAID.  I've gone through and formatted all my drives, even have the array about half full.  Then I read on the wiki that all drives going forward, no matter if they're AF or not, should use the 4k alignment.  I specifically changed this when setting up my unRAID and pre_clearing the drives since none of my drives are AF/4k.  Am I taking a big performance hit by having them unaligned?  I can afford to start over because right now I've only lost time and all the data I have copied over I can recopy over.  Here are the drives I have in my unRAID:

 

(1) SAMSUNG_HD204UI (updated the firmware, currently my parity drive)

(4) SAMSUNG_HD103SI (currently 1 is my cache drive)

(4) SAMSUNG_HD154UI

(4) WDC_WD15EADS

 

In the near future, I will be adding from my FreeNAS (once data is copied over):

(4) SAMSUNG_HD204UI

(4) Hitachi Deskstar 2 TB 3.5-Inch CoolSpin

 

and today I will be adding:

(1) Western Digital 2TB Caviar Black 6gbps 7200RPM (new parity drive)

(1) Western Digital 750GB Caviar Black 6gbps 72000RPM (new cache drive)

 

What should I do?  None of these drives are AF/4k but the wiki seems to say we should be formatting them as such.  Any help would be appreciated!  Thanks.

 

 

[Joe L.]

If they are NOT the one type of drive that has performance issues if not partitioned so it is aligned on a 4k boundary, you get NO performance impact.  None, zip, nada.

 

That one type is a WD EARS drive. 

 

Whatever you are reading is wrong, or you are mis-interperting what it is trying to say.    It not that all the new (non-advanced-format) drives "should" use 4k alignment, it is that they "can", as they can be addressed at any 512 byte boundary, as all drives have since the early days of MS-DOS.  so you might as well just make all the drives the same since if the boundary is at a 4096 byte boundary, it is ALSO at a 512 byte boundary.

[savestheday]

If they are NOT the one type of drive that has performance issues if not partitioned so it is aligned on a 4k boundary, you get NO performance impact.  None, zip, nada.

 

That one type is a WD EARS drive.  

 

Whatever you are reading is wrong, or you are mis-interperting what it is trying to say.     It not that all the new (non-advanced-format) drives "should" use 4k alignment, it is that they "can", as they can be addressed at any 512 byte boundary, as all drives have since the early days of MS-DOS.  so you might as well just make all the drives the same since if the boundary is at a 4096 byte boundary, it is ALSO at a 512 byte boundary.

 

Phew!  You just saved me a lot of time, thank you much!  I was misinterpreting

http://lime-technology.com/wiki/index.php?title=Advanced_Format_Drives

thinking that we had to format all drives as 4k.

 

So, if I get a 4k drive, then when I preclear it, preclear will pick up that it's 4k and align it as such, right?  Also, I'll have to change that default setting back to 4k before I format it, correct?  

 

Thanks again Joe.

 

/EDIT

 

Just noticed that my HD204UI IS an AF drive.  Damn.  Gonna have to format that as AF now. 

[lionelhutz]

Your present non AF drives don't care so they are fine either way. I would recommend you just change the setting to 4k aligned and let every future drives be aligned that way. Just NEVER use a jumper on a new EARS drive.

 

You have to either have the setting as 4k aligned or use the -A switch with the preclear script to get the drive 4k aligned. If you preclear without either then the drive is not aligned, even if you change the setting before hitting the format button. The preclear writes the partition so the partition with the wrong alignment would already be created by the time you saw the format button.

 

As for the HD204UI - I don't believe they suffer much if not aligned but you can change it if it makes you feel better. You indicate you are replacing it so the preclear script has an option to just zero the drive with no pre or post read cycles. I would run the script that way (should only take ~8hrs instead of ~25 hrs) and then add it as a data drive.

 

I believe if you just type preclear_disk.sh -? then a help screen appears with the options.

 

Peter

 

[Joe L.]

If they are NOT the one type of drive that has performance issues if not partitioned so it is aligned on a 4k boundary, you get NO performance impact.  None, zip, nada.

 

That one type is a WD EARS drive.  

 

Whatever you are reading is wrong, or you are mis-interperting what it is trying to say.     It not that all the new (non-advanced-format) drives "should" use 4k alignment, it is that they "can", as they can be addressed at any 512 byte boundary, as all drives have since the early days of MS-DOS.  so you might as well just make all the drives the same since if the boundary is at a 4096 byte boundary, it is ALSO at a 512 byte boundary.

 

Phew!  You just saved me a lot of time, thank you much!  I was misinterpreting

http://lime-technology.com/wiki/index.php?title=Advanced_Format_Drives

thinking that we had to format all drives as 4k.

 

So, if I get a 4k drive, then when I preclear it, preclear will pick up that it's 4k and align it as such, right?  Also, I'll have to change that default setting back to 4k before I format it, correct?  

 

Thanks again Joe.

 

/EDIT

 

Just noticed that my HD204UI IS an AF drive.  Damn.  Gonna have to format that as AF now. 

Only the EARS drives... and even then, only if you did not add a jumper to have it electrically add one to the partition  None of the others have the same performance hit, and even on the EARS drives it is not noticeable for most people.  Leave all existing drives as they are.

[savestheday]

Your present non AF drives don't care so they are fine either way. I would recommend you just change the setting to 4k aligned and let every future drives be aligned that way. Just NEVER use a jumper on a new EARS drive.

 

You have to either have the setting as 4k aligned or use the -A switch with the preclear script to get the drive 4k aligned. If you preclear without either then the drive is not aligned, even if you change the setting before hitting the format button. The preclear writes the partition so the partition with the wrong alignment would already be created by the time you saw the format button.

 

As for the HD204UI - I don't believe they suffer much if not aligned but you can change it if it makes you feel better. You indicate you are replacing it so the preclear script has an option to just zero the drive with no pre or post read cycles. I would run the script that way (should only take ~8hrs instead of ~25 hrs) and then add it as a data drive.

 

I believe if you just type preclear_disk.sh -? then a help screen appears with the options.

 

Peter

 

 

I'm familiar with that pre_clear switch (think it's -n) that lets you skip pre and post reads.  I do that then:

 

preclear -n -A /dev/sda

 

Thank you so much for your help.