WD20EARS Windows 7 partitioning and formatting


#1

Hello,

I purchased four 2TB green WD20EARS drives with plans to use a backup and music playback mostly. But then I got the wild idea to use one as the boot drive in a new Dell. 

So, I have a few questions to ask here (could not find the answers anywhere on the web after hours of searching).

  1. How do I determine if a WD20EARS is currently aliagned and using the advanced formatting? I tried Data Lifeguard Diagnostic but I could not see the alignment status. It reports NTFS, but I guess that’s what I would generally see for any Micosoft OS.

  2. I accidentally formatted one drive with Windows 7 before putting data on it. Did I mess up the advanced formatting/alignment for Windows 7?

  3.  Regarding my boot decision, mentioned above, I installed Windows 7 on one green WD20EARS without partitioning first, thinking I could shrink and partition later (as I have done in other situations). But now I’m not sure if:

a) Did installing W7 affect the algnment and advanced formatting? (I dont’ think so, but I’m not sure)

b) What happens if I do shrink and create new partitions? How will that affect aignment and advanced formatting?

c) I have read reacently that green drives aren’t recommended as boot drives. So, if I take it out and delete my install,

do Ihave to simply delete/empty trash, etc.? Or, what’s the best way to wipe? Formatting software, or in W7 or OSX?

d) If I do keep the boot setup, what’s the best tool to repartition without losing the alignment/advanced formatting? Unfortunately, W7 limits how much I can shrink the volume, so that’s not the best solution anyway.

Thanks for your patience in reading this long first post. I’m short on time, and frustrated by not being able to find the answers, even by searching here so far.

Thanks,

-WinLInMac


#2

PS - on further reading about Acronis True Image WD Edition, it is beginning to look like I can use it for many of my partitioning/formatting concerns.

I would have thought so, but when I first read up on it, the software seemed designed for backup primarily. I couldn’t tell if it would do safe advanced format repartitioning or clean formatting with the proper alignment.

I’m still not entirely sure, so help is appreciated.

Even if I can shrink my install disk partition and make new ones, or verify the status of my accidental W7 format, using this tool, I’m still wondering whether I should be using the green drive as a boot. I figured it would be fast enough for most things.  I out-grew the 320 on my old computer sooner than I would have liked for stuff I like to have quick access to.

Any feedback or advice greatly appreciated!


#3

Short answer: Your partitions will be aligned if they begin at sector 2048 (or some multiple of 8) when the alignment jumper is out. Alternatively, the first partition will be aligned if it begins at sector 63 when the alignment jumper is present.

Long answer:

First of all, when using Windows 7, there must not be a jumper on pins 7 and 8. The purpose of this jumper is to add a +1 sector offset to each LBA. Operating systems such as Windows XP begin a partition at sector 63, which means that every 4KB cluster then spans two physical 4KB blocks. By adding a single sector offset, the drive shifts sector 63 to LBA 64, which then aligns the partition. However, alignment is only guaranteed for the first partition, since each track has 63 sectors, and each partition may or may not end on a track boundary.

Operating systems such as Vista and Windows 7 begin the first partition at sector 2048, which is automatically aligned, as long as the above jumper is not installed. Subsequent partitions are also aligned to 4KB blocks.

As stated above, your partitions will be aligned if they begin at sector 2048 (or some multiple of 8 ) when the alignment jumper is out. Alternatively, the first partition will be aligned if it begins at sector 63 when the alignment jumper is present.

To determine whether a drive has 4KB sectors, you need to examine the 512-byte data block returned by the drive in response to an ATA Identify Device command. You can retrieve these 512 bytes of data using the Text Copy function in CrystalDiskInfo:

http://crystalmark.info/software/CrystalDiskInfo/index-e.html

The Identify Device data are documented in section 7.16.7 of the ATA standard.

Working Draft AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS):
http://www.t13.org/documents/UploadedDocuments/docs2008/D1699r6-ATA8-ACS.pdf

Word #106 Physical sector size / logical sector size

Word #117-118 Logical sector size (DWord)

Word #209 Alignment of logical blocks within a physical block
bits 13:0 — Logical sector offset within the first physical sector where the first logical sector is placed

Unfortunately, the above words are optional, so an AF drive may or may not identify itself as such.