# FreeBSD 9 and AdvancedFormat disks



## Twister (Jun 21, 2012)

Hello!

I want to replace old disk to new. New disk is Seagate Barracuda Green (Adv. Format)
It has 512 bytes logical, 4096 bytes physical sector size.
As I know slices and partitions have to be aligned to physical sectors (x8 logical) to get good performance.

So question is - does FreeBSD 9 know about Advanced Format disks? I want to use GPT. Will gpart make all in proper way (aligned to 4K) or I should do it myself?


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## wblock@ (Jun 21, 2012)

gpart(8) will do it if you use the -a option.  See the man page.  It's not too hard to calculate yourself, either.  Start the first filesystem partition at 1M, and make all partitions even multiples of 1M or 1G, and they will be aligned.  See the GPT section of Disk Setup On FreeBSD.


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## Twister (Jun 23, 2012)

Thank you for your answer.
New disk is installed and working.


```
[B]root@home ~#[/B] gpart show ada2
=>        34  2930277101  ada2  GPT  (1.4T)
          34           6        - free -  (3.0k)
          40        1024     1  freebsd-boot  (512k)
        1064    16777216     2  freebsd-ufs  (8.0G)
    16778280    16777216     3  freebsd-swap  (8.0G)
    33555496  2896721632     4  freebsd-zfs  (1.4T)
  2930277128           7        - free -  (3.5k)

[B]root@home ~#[/B] dd if=/opt/The.Big.File.17GB of=/dev/null bs=65536
269787+1 records in
269787+1 records out
17680761214 bytes transferred in 132.216720 secs ([B]133 725 608 bytes/sec[/B])
```

Transfer speed is much faster than old 750GB Barracuda.


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