Just bought a Thecus N7700 and 7 x 1.5TB WD Drives - bad move?

Hi all

Today I'm really kicking myself as I usually do lots of research before buying things:( Anyway, I currently have a Thecus N5200B with 5 x WD 1TB Caviar Greens configured in a RAID5 (all discs in array).

As my storage space is running low, I've taken delivery of a N7700 and 7 x 1.5TB WD Caviar Green drives. I bought all of this kit from Scan, and I went for the N7700 because it's the cheapest (by far) 7 bay NAS on the market - the Qnap 6 bay equivalent is almost a grand, versus £609!

On scan's website the HDD compatibility list throws out an error, and stupidly I didn't follow this up and google it. Anyway, I've just installed it and set up a new RAID5, but then I came on these forums and read about a ton of issues with 1.5TB/2TB HDDs with the N7700.

The question is, have I made a big mistake? I don't want to be in the position of having HDD failures, as I have about 6TB worth of data to put on there (all media files - DVD and BluRay rips).

I'm wondering if I should maybe look at changing the HDD to the 2TB Hitachi ones (as they are officially supported), or even change the NAS and spend loads more money looking at either the 6 or 8 bay Qnap NAS?

Secondly, I've also read that ext3 only allows a maximum of 8TB space, but I'm a little confused by this. In a RAID5, you lose some capacity anyway, but is this "lost" element included in the 8TB? If I were to put 7 x 2TB drives into the N7700, how would I maximise the space, as I've heard ZFS can be unreliable, and I don't know what XFS is?

If anyone could help it would be appreciated. I don't want to start transferring files across today if I'm on a loser to begin with....

Cheers

The issue with the WD discs seems mostly to be disabled TLER (cause the disc goes into sleep without notifying the OS and thats not a good idea on a RAID) - so check if TLER is enabled (also othes NAS have problems at the moment with WD drives).
I would choose XFS as filesystem - ext3 has this limitation and ZFS is not part of the kernel. The size limitation is not the summary of all discs, but the size available after raid construction.
br
Peter

i don't think you need to change the NAS. it will be wise to change the hard drives to what's on it's official compatibility list
http://www.thecus.com/Downloads/HDD_...2009-10-22.pdf
they have listed Hitachi and Seagate 2TB. shoudn't be problem. it is not worth it to spend more on NAS. they pretty much have the same function, but Thecus' performance is pretty good.

about the 8TB limitation, the capacity used for redundancy does not include in the 8TB. it is the actual RAID volume.

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Originally Posted by peterfu

The issue with the WD discs seems mostly to be disabled TLER (cause the disc goes into sleep without notifying the OS and thats not a good idea on a RAID) - so check if TLER is enabled (also othes NAS have problems at the moment with WD drives).
I would choose XFS as filesystem - ext3 has this limitation and ZFS is not part of the kernel. The size limitation is not the summary of all discs, but the size available after raid construction.
br
Peter

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Thanks, how do I check this? My RAID is already constructed! Do you mean TLER should be enabled or disabled? I would guess it's enabled by default?

I wonder if Scan will take them back, doubt it :eek:

hmmm, just found this about TLER: http://en.wikipedia.org/wiki/Time-Li...y_-_WDTLER.EXE

The article You have found says everything - if You have models where You can't enable TLER, then replace the discs, otherwise You might have regular disc drops from the raid.
br
Peter

Stupid question....but how do I check?

The model number shown on the N7700 console is WDC WD15EADS-00P

Thats not a stupid question, and the answer seems not so easy.
I've read somewhere that on discs manufactured until October TLER can be activated - on newer Caviar discs not - so the best would be to ask WD and send them the serial numbers
br
Peter

Same version as me, dont think you can enable TLER.

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Originally Posted by Smurfin

Stupid question....but how do I check?

The model number shown on the N7700 console is WDC WD15EADS-00P

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Guess WD finally got tired of seing people getting desktop drives for enterprice use :)

The RE4-GP (WD2002FYPS) is supposed to be used for this.
Sad thing is these carry a 30% price premium :(

Wonder if anyone have tried these...

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Originally Posted by Gazer75

Guess WD finally got tired of seing people getting desktop drives for enterprice use :)

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No, I use mine for BluRay streaming:angst:

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Originally Posted by Manzzon

Same version as me, dont think you can enable TLER.

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What did you do? Have you stuck with them and have you had any problems?

Im moving data from my N5200 to my N7700, so far its working great.

Im doing some more testing before I let my N5200 go. :)

Anyone knows how often this drop out problems may come? If im not wrong they only occur when theres bad sectors on the harddrive that it cant write to. Can someone confirm this?

I also think Thecus can fix this TLER problems with a update so you can adjust the timeouts like some hardware RAID cards have?

Quote:

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Originally Posted by Smurfin

What did you do? Have you stuck with them and have you had any problems?

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Well I contact Scan today, and they're taking all 7 WD drives back, just got my RMA number :)

However.....what drives do I replace them with? I'm thinking either the Hitachi Deskstar 2TB or the 2TB Seagate...any recommendations? I can't seem to find ANY info on the Deskstar - Scan told me out of 450 sold, they've had 7 RMA'd, Seagate is lower and they've had no WD RMA'd (though they've sold less than 100 of these). Of course, the RMA numbers don't tell you what was returned as unwanted, so fair to say that the Deskstars seem to have a low failure rate.

Just want to be sure before I push the button....

i've had problems with both hitachi and seagate drives in the past (not thecus/nas/raid related, just single drives) so i went for 4x 1.5tb samsung spinpoints in my N7700 and so far (touch wood) I've had no issues and would recommend them.

i plan on buying more disks as my capacity requirements increase, but so far i haven't needed them yet.

My raid5 has a capacity of 10.7TB usable....I'm half way already with lots more content.....mmmm maybe I need two.....

Gutted. Been running my N7700 for almost a month now and hey presto....RAID is degraded this morning. Disc one has dropped, it doesn't even show in the NAS gui (well it showed in disc status as "Ok" but when I tried to scan it I got a message saying it doesn't exist).

Going to take it, put it back in and see what happens....