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[Steve Pitts]

Folks,

I've had a dig around and cannot find an answer to this, so please forgive a first-timer if I've missed something obvious.

I have just bought a DNS-323 into which I've inserted a WD20EARS 2TB drive, only to discover the caveats about 4K sector drives when searching for information on poor throughput. Since this is a brand new setup and will be providing off machine backup of files that are always held elsewhere too, I decided to bite the bullet and try the 1.10 beta firmware. I had a smooth update process, followed by a factory reset and a re-format of the drive, but how can I check whether or not my drive has been correctly formatted for 4K sectors?? I was hoping that the new firmware would improve my data copying speeds, but it has made no difference whatsoever so I'm wondering whether or not the 4K format has taken effect.

[Steve Pitts]

To fill in the deafening silence in response to my original post I have been forced to try and find out how to do this for myself, which involved something I'd intended to avoid - installing ffp (the Fonz fun_plug) - and inveigling the assistance of a *nix expert colleague, who was so impressed by the value for money of the unit that he bought one for himself (a tip of the hat to Mark Gosling for what follows).

To cut straight to the chase, for those that already have opened up their devices, the command to issue is:

fdisk -ul

which will generate output that looks something like:

Code: [Select]

root@DLink_NAS:/mnt/HD_a2/ffp/home/root# fdisk -ul

Disk /dev/sda: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes

   Device Boot      Start         End      Blocks  Id System
/dev/sda1              64     1060287      530112  82 Linux swap
Partition 1 does not end on cylinder boundary
/dev/sda2         2084368  3907024064  1952469848+ 83 Linux
/dev/sda4         1060288     2084367      512040  83 Linux
Partition 4 does not end on cylinder boundary

Partition table entries are not in disk order
root@DLink_NAS:/mnt/HD_a2/ffp/home/root#
The important factor is that the start values are all exactly divisible by 8 (since the output is showing 512 byte blocks, of which there are eight in 4K).

For those that have not ventured into fun_plug territory I can thoroughly recommend the DNS323 wiki and the detailed walkthrough on installing ffp at NAS-Tweaks.net

[lookingforinfo]

Thank you for this additional information.

[fredfox-uk]

Thanks Steve, proved very useful information for me.

[jackh]

I have your exact same setup (single drive, WD20EARS; DNS-323 with fw 1.10b7) and after following all guides I even obtained an exact copy of your output from fdisk.

The important factor is that the start values are all exactly divisible by 8 (since the output is showing 512 byte blocks, of which there are eight in 4K).

So Steve: I may be misunderstanding the key confirmation but, does that sample output you provided mean that all is good and the firmware formatted the drive with 4K by itself? or not? (the "512" number there confuses me)

Edit: I am popping this question because I just can't find anything closer than your post in this regard. Plus the D-Link guys say that 4K is "supported" in this firmware (although it's beta, so I can't expect commitments...) but there's no way to tell the firmware "use 4K" or "use 512" as an option.
Should I just trust that the firmware automagically detected the 4K HDD and formatted it properly? Yet it won't tell or confirm that minor detail...

Would you (or D-Link gurus?) please clarify? Thanks!!!
Jack The Confused

[Steve Pitts]

after following all guides I even obtained an exact copy of your output from fdisk

Which makes perfect sense, since the geometry of our disks is identical and two of the created partitions are of a fixed size. Short answer to the rest of your post is that the beta firmware has correctly formatted the disk for 4K blocks. What follows is background detail in answer to specific queries or statements:

does that sample output you provided mean that all is good and the firmware formatted the drive with 4K by itself? or not? (the "512" number there confuses me)

The version of the fdisk command on the DNS323 is reporting a 512-byte sector size because a) it doesn't understand anything else and possibly b) the drive is lying to it about the real sector size (that depends on the jumper settings with the WD EARS disks). That is what we are expecting and why we are able to use multiples of 8 to determine that the drive is correctly formatted.

there's no way to tell the firmware "use 4K" or "use 512" as an option

That is probably because D-Link took the (perfectly reasonable) decision to simply format all drives - AFT or not - to be 4K compliant rather than worry about the real geometry of the installed disk(s). That might waste a (relatively) tiny chunk of space but keeps things simple.

Should I just trust that the firmware automagically detected the 4K HDD and formatted it properly?

Yes, because it doesn't need to detect the 4K disk(s) (as per my previous paragraph) and the sector alignment is correct (it would be different if you formatted the disk with firmware prior to 1.10, probably with partitions starting on odd sector boundaries)

Yet it won't tell or confirm that minor detail...

That bugged me too, hence my original post. However, all of the reading I've done since posting that confirms the advice of my colleague Mark that sector start values divisible by eight indicates that the new firmware has done things properly for 4K format disks.

[jackh]

Thanks Steve, you're my new geeky hero...