Help with understanding sata controllers/ BYO Storage Chasis

ginjaninja

ginjaninja

ginjaninja

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I am considering a raided storage solution using SATA hdds.
Considering 7 disks + 1 parity RAID 5. (start with 2TB HDDs, but dont want to be constrained from upgrading HDD sizes).
Ideally want raid controlled by hardware not os (for robustness/flexibility rather than speed)
I am trying to work out if i build my own (own case, own controller, own pc) whether it offers better value for money.
I dont need stellar performance, just something approaching the native read/write speed of the disk (ie dont want NAS/ to access over a gbit network).
So i am considering an external esta connected storage chasis or just a BYO PC.

Qu 1. Do controllesr with SFF-8087 connectors like Supermicro AOC-SASLP-MV8, 8-Port SAS/SATA Card. mean that four HDD are sharing the sata III port bandwidth? IE its more important to buy a controller with 6gbps support.


Qu 2. "4/5 port" controllers with 4/5 physical ports eg. startech or highpoint or lian-li are a better price point than say a 8 port lsi controller. i presume 2 x 4port controllers can not be bonded (at hardware level) to support a RAID over 8 hdds?...

That said two "4 HDDs+1 parity" bundles using a lian li 5 port sata, might be more cost effective (True 8 physical port controllers are much more expensive, if the supermicro above wont work).


Qu 3. Is it the case that the these types of controllers cards (like the startech/highpoints,supermicros) will not have the type of max hdd size constraints that some prebuilt chassis have?

Qu 4. IS a SAS/SATA controller any less good than a pure SATA controller for my requirement? do i need to worry that it is a SAS controller as well. (i wont use SAS?)

thanks
 
ginjaninja said:
Qu 1. Do controllesr with SFF-8087 connectors like Supermicro AOC-SASLP-MV8, 8-Port SAS/SATA Card. mean that four HDD are sharing the sata III port bandwidth? IE its more important to buy a controller with 6gbps support.
Click to expand...
That connector is just a 4 into 1 solution, it's designed for server chassis so that only one cable needs to run from the controller to the backplane. Each device has it's own dedicated link, there's no bandwidth sharing.

ginjaninja said:
Qu 2. "4/5 port" controllers with 4/5 physical ports eg. startech or highpoint or lian-li are a better price point than say a 8 port lsi controller. i presume 2 x 4port controllers can not be bonded (at hardware level) to support a RAID over 8 hdds?...
Click to expand...
Some of the highpoint controllers can run arrays across multiple cards but check the specs first. Avoid the Startech and Lian Li controllers, they're not proper hardware cards and generally run basic Silicon Image or Marvell controllers.

ginjaninja said:
Qu 3. Is it the case that the these types of controllers cards (like the startech/highpoints,supermicros) will not have the type of max hdd size constraints that some prebuilt chassis have?
Click to expand...
It's difficult to tell whether quoted max HDD sizes are an actual limitation or just something that hasn't been tested by the manufacturer. For example I'm running 5x2Tb on an old RocketRaid 2320 which doesn't have anything bigger than 500Gb on it's compatability list.

ginjaninja said:
Qu 4. IS a SAS/SATA controller any less good than a pure SATA controller for my requirement? do i need to worry that it is a SAS controller as well. (i wont use SAS?)
Click to expand...
You can run SATA drives on a SAS controller but not the other way round. There's nothing wrong with SAS controllers, they tend to be more readily available than pure SATA controllers simply because the market for hardware RAID5 cards is also the same market as SAS disks.
 
rpstewart said:
That connector is just a 4 into 1 solution, it's designed for server chassis so that only one cable needs to run from the controller to the backplane. Each device has it's own dedicated link, there's no bandwidth sharing.


Some of the highpoint controllers can run arrays across multiple cards but check the specs first. Avoid the Startech and Lian Li controllers, they're not proper hardware cards and generally run basic Silicon Image or Marvell controllers.


It's difficult to tell whether quoted max HDD sizes are an actual limitation or just something that hasn't been tested by the manufacturer. For example I'm running 5x2Tb on an old RocketRaid 2320 which doesn't have anything bigger than 500Gb on it's compatability list.


You can run SATA drives on a SAS controller but not the other way round. There's nothing wrong with SAS controllers, they tend to be more readily available than pure SATA controllers simply because the market for hardware RAID5 cards is also the same market as SAS disks.
Click to expand...

thanks for advice

re:It's difficult to tell whether quoted max HDD sizes are an actual limitation or just something that hasn't been tested by the manufacturer. For example I'm running 5x2Tb on an old RocketRaid 2320 which doesn't have anything bigger than 500Gb on it's compatability list.

would you say its no less likely that a storage backplane or a direct connection to a controller would support larger than tested drives then. just go with a reputable manufacturer and hope for a firmware if it becomes necessary. I ask because most of the backplane chassis list max support hdd size but the controllers themselves dont lend to list this limit.

do you know of good storage chassis that you would recommend (with at least 8 ports). And if the supplied controller turned out to be naff, would you expect a premium card to be able to drive a chasis supplied with a cheap and cheerful card (as an upgrade in the future)
 
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