D-Link Forums
The Graveyard - Products No Longer Supported => D-Link Storage => DNS-321 => Topic started by: craftsman on March 04, 2010, 12:06:26 PM
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I just bought two WD20EARS drives and then read about the "Advanced Format" which uses 4k sectors instead of 512k sectors. Does anyone know if the DNS-321 will handle them correctly? I understand the OS needs to be smart enough to align it on the proper boundaries or else there will be significant performance issues.
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Apparently, they work fine. Several people have posted here with positive results. Point of correction, it's 512 byte sectors vs. 4 kbyte sectors. :)
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I probably should have asked if the DNS-321 can make use of the 4k sectors or should I be using the jumper that is used for OSes like XP that don't work as efficiently with 4k sectors.
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I'd be surprised if you didn't need the emulation feature, I doubt the NAS will handle the 4k sectors. :)
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It looks like the standard partitioning isn't aligned with the 4k physical sectors on these drives causing performance issues.
http://forums.dlink.com/index.php?topic=11631.0
D-Link is hopefully working on revised firmware since 4k physical sectors are going to be increasingly common going forward.
I think the 4k sector drives work fine with systems like XP that use 512 byte sectors as long as the partitions are aligned on a 4k boundary. XP doesn't do that but WD offers a utility for XP users to realign the partition.
From the thread above it looks like the DNS-321/323 also doesn't align the partition on a 4k byte boundary causing performance issues and the fix isn't something many users would be comfortable doing themselves.
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I'll keep my current "old technology" drives for my NAS units for now. :D
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I have two of the 1.5tb models and I don't seem to be having performance issues (I haven't been able to do a proper bench mark as of yet though)
the only thing so far I have noticed is I can't do a scan disk on the volume -- it just fails right off the bat.
and I'm just testing it now -- but the extended smart test seems to be hanging at 10% for either Drive -- the quick test is fine though.
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Since the NAS doesn't begin to tax even the slowest of standard SATA drives, I doubt that major performance issues will be a major problem for this particular use.
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any concerns/suggestions regarding the disk scanning or extended smart testing? -- I'm guessing it has to do with the 4k sectors but if anyone could confirm I would feel better about it.
any suggestions as for realigning the drives manually?
I'm afraid I am not proficient with Linux -- but I can follow a script -- I have been reviewing some of the posted information -- but I can't make sense of what is actually required to realign the drives in a raid format (with funplug)
EDIT:: I just checked -- still sitting at 10% -- loaded up putty via ssh and check top -- doesn't appear to be anything going on -- almost no cpu usage at all -- the drive I'm testing is running about 4 degrees hotter then the other one at the moment though
One More Edit::: so it looks like we should be able to use fdisk to specify the 4k blocks -- or am I mistaken about the use of Fdisk in linux -- or is the b parameter limited to 2k?
I'm a little unsure about the format for the rest of the params required to achieve this.
Thanks
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so I have been looking around and I found this which is supposed to realign to the 4kb boundaries:
fdisk -H 224 -S 56 /dev/sdb
running fdisk with these parameters ensures that every partition you create is aligned to 4KiB boundries.
again due to my ignorance with Linux I'm not entirely sure how to proceed with a mirrored configuration.
the original source here:
http://community.wdc.com/t5/Desktop/Problem-with-WD-Advanced-Format-drive-in-LINUX-WD15EARS/m-p/7573;jsessionid=9EA7E3150F37F985500B3C344CCDA474#M369
personally I have a good setup for testing as I just set this up and I have very little data on the Nas so far so if anyone is willing to give a little guidance on this -- I don't mind testing it out if anyone has some thoughts on what to do to move forward on this.
Thanks for your time.
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Linux is supposed to support 4k sectors natively. Might depend on the kernel version. DNS -321 runs Linux, BTW.
Have you tried configuring the drive with it set to 4k mode?
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I ended up manually having to set the bounds -- there is a great thread in the 343 forum on how to accomplish this.
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So it sounds like the issue here is that the DNS-321 by default uses 512B sectors and starts the first partition on sector 63 (ala WinXP) so there is a misalignment on the newer 4k sector drives. It still works, but there are many unnecessary read-modify-write cycles going on in the drive (see http://anandtech.com/show/2888/1)
It is possible to telnet in and re-align the partitions to 4k sector boundaries, but this will need to be done every time the DNS-321 formats a drive, correct?
Haven't purchased a DNS-321 yet, but will probably stick with the older 512B physical sector WD Green drives for now.
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Haven't purchased a DNS-321 yet, but will probably stick with the older 512B physical sector WD Green drives for now.
....I *just* purchased the DNS-321..and although i wanted to wait for the 2TB EADS drives to drop in price, I bit the bullet and just got the 2TB EARS from the 'Egg with the $20 off of each.....
From what I've been reading the EARS can work ok with the DNS-321, but may require some finagling...
My questions:
1. Can we, in fact, just jumper the drives, or does that only work with older NTFS formatting systems like XP? Since the '321 uses Linux and formats EXT (2/3?), does this mean the jumper is basically useless?
Assuming the above is true, and that we can't jumper the drives then:
2. GideonOmega, can you please verify the exact commands you used and how you did it? I've been perusing the 343 thread, and admittedly am getting a bit confused.
Do we need to format these on separate linux box? do we need to create multiple partitions, or just one large one per drive?
I plan to run these in a mirror configuration...
R
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The jumper will not work because the DNS-321 creates 3 partitions and thus only the first partition would be fixed.
Repartitioning via Linux did not work for me. All the tools I tried could not handle the ext3. I tried for several weeks before I went back to 512k sector drives.
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Read the 343 guide. I was able to repartition (realign) and put 2 2TB EARS back into RAID 1.
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I don't think the alignment is the only issue, it's also the deep recovery procedure when it occurs.
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I don't think the alignment is the only issue, it's also the deep recovery procedure when it occurs.
+1, even better .. alignment isn't an issue for the DNS-321, if anyone needed an alignment to get the drive working then either the DNS firmware is malfunctioning or the HDD is problematic.
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I wasn't sure if the version of Linux on the DNS-321 was updated to support the new structure, but I am sure that the real issue is the deep recovery procedure. :)
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Dlink does not support 4k drives in their units. However, I managed to format manually. Here's how I did it: http://www.consumedconsumer.org/2010/06/upgrading-my-dns-323-to-2-x-2-tb-ii_08.html