Unfortunately no one can be told what fun_plug is - you have to see it for yourself.
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Hi everyone,
I've just registered to find out answers about this NAS.
I need a small box to store my data, from my laptop and from my Home PC. Nothing more...for now!
I've just purchased another cheap NAS, with gigabit and RAID1 functions (the only things I need), but I discovered that RAID is based on software module (OS Raidtools).
I don't trust in software mirrors, so I want to know if RAID1 in DNS-323 is implemented in his SATA embedded controller or by linux OS.
And, if possibile, I want to know how long does it take build (or rebuild) a RAID1 drive with two 750 Gbyte drives (I've two Samsung 750 Gbyte SATAII 32 Mbytes cache, Spinpoint or something so).
Thanks in advance
M
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It is software RAID using mdadm. The original build is fast, just the time it takes to format the drives. I have not had to rebuild one of that sizes, so I cannot comment on that.
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The rebuild is fairly quick - a rebuild of my 80GB RAID1 pair takes less than 20 minutes - although it will probably vary with the amount of data - in this case around 56GB.
I'll also point out that this is significantly quicker than a RAID1 pair on - for example - an LSI Logic hardware controller, when a build/rebuild runs around 12 hours with 146 GB Ultra SCSI-3 disks.
You need to recognize that you're not going to find hardware RAID on a "cheap NAS" and either choose to live with software RAID or bite the bullet and pay the price, and as always .....
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Wow!
Thank you for you quick and complete answers!
The problem is I always use high-end equipment in my job (HP EVA 4000, EMC2...) and I don't know anything about SOHO equipments...On modern and cheap motherboards there's an HW RAID controller, I used one of that and it was very quick, so I thought this kind of NAS use similar solution...
Well, thanks again, now I only need if someone can tell me build/rebuild times with 750 Gbyte HDD...based on fordem experience it will last 1.5 - 2 hrs...
bq041, how long does it take formatting your WD 1Tbyte drives?
Thanx again
M
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I have to remember. I think it was in the order of 30 minutes or so. I can probably format one when I get home from work and give you an acurate time. I do partition and format them from the OS via telnet and not from the D-Link utility. I'm currently running all my drives in Standard mode. I just recently used mdadm to disassemble the array.
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The bulk of my experience is on enterprise grade equipment - more Dell than HP, and yes, I work with EMC gear also.
Go take another look at those "modern and cheap motherboards" with HW RAID controllers - do they offer anything other than RAID0, RAID1 and sometimes a combination of the two - RAID1+0/RAID0+1/RAID10?
If that's what you're looking at, there is no RAID controller perse on those boards, as there is no XOR logic, the RAID processing is done by the system processor in pretty much the same way it would be done with software RAID - one example would be the Adaptec HostRAID which can use either the Intel ICH6 or the Silicon Image SATA controllers.
To differentiate from Hardware RAID - which it is not (since there is no XOR logic on the controller) - and software based RAID, which technically speaking it is, although some people may argue since the OS is completely unaware that a "RAIDed" logical drive exists - I call it "driver based RAID" - and the perhaps more traditional software RAID, where the RAID members are managed by the OS, I call "OS driven RAID" - the trade nickname however is "fakeRAID".
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I formatted one of the 1 TB drives. 14 minutes exactly.
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Formatting is nothing compared to rebuilding. I just had some out of sync raid1 recently after upgrading to 1.05. As I was copying large volume of data back into the device, I notice that status shows drives are rebuilding. So, I quickly stopped copying files into the device and let the rebuild run by itself. It took around 1 hour to rebuild and at that time, my data is around 100GB.
And I do agree that hardware RAID is always better. They works at so low level that even OS is unaware of it. But for the price you are paying for dns323, cheap motherboard and cheap raid cards, NO WAY you will be getting hardware RAID. All of those run on software raid which relies on drivers and OS to run the raid.
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It seems that everyone (mee too...) is right.
Fordem writes exactly the situation: a real hardware controller use XOR logic in it, and everything by itself (the main CPU is not involved). I guess ServeRAID from IBM or HP SmartRAID from HP works in this manner, and costs like a complete motherboard with CPU.
I'm so interested in hardware RAID (even with no XOR) b'se it minimizes failure: If you have one of this (like the Adaptec you speck about) you "present" to OS a drive. OS doesn't know is a virtual drive. If you use LVM philosophy (OS manage the virtual drive) is an OS module that runs everythimg.
It means there's more components involved in disk management. If you use HW controller, it's firmware have only to copy same infos on the two disk. If it works good, you don't need to upgrade it (I don't upgrade things that works...), but you can do all the mess you want with OS. It happened that Dlink make changes in it's firmware to fix other components, with a drawback in RAID managment (discovered after someone loses something...)
If the controller manages the drive, Dlink bugs surely doesn't affect RAID, that is the only thing I need...
Thanx!
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Actually no - IBM's ServeRAID 7e is an oem license of the Adaptec HostRAID technology - you need to check the version numbers to be sure of what you're getting. I know that Dell also licenses the technology and I suspect that HP does also.
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