Supported Sata RAID Controllers, any experience?

[silver565]

I'm looking at building an iSCSI & NFS server with Freenas, however I'm having trouble finding supported Raid cards(Not software raid, but raid where Freenas sees the Virtual drives as disks).
I had an Intel raid card but that wasn't supported. Has anyone used something like this?

http://pricespy.co.nz/product.php?p=394481
http://pricespy.co.nz/product.php?p=394479

Any help would be appreciated

 

[survive]

Hi silver565,

Is there any reason why you don't use ZFS to do your storage? It really is the way to go if you have the hardware to support it's appetite for RAM.

Personally I wouldn't be looking at HP cards if you really honestly do want to do hardware RAID....they are just to weird & can be funky in non-HP hardware (I think you need to have the card in a proper HP server to update the firmware on them, for example). Take a look at the LSI cards, don't get something to new, I would look for something based on the "2008" series of chips. In general I like to use hardware that was out before the underlying FreeBSD version was released.

If I were you I would take the nearly 400 bucks the hardware card would cost you and spend it on a plain old SAS HBA, a nicer case, a better board, a boatload more RAM & lunch to celebrate the fact I'm still under budget.

-Will

 

[silver565]

Thanks for the input. I'm not too familiar with ZFS. What would the advantage be?

Basically I want to setup this iSCSI box so that it has hardware raid. The reason is that I want to have redundancy. If a disk fails the raid controller can rebuild the array with the replacement disk. There are a couple of intel RS2WC80's in ESXi boxes which work well, but they are not supported by FreeBSD 7.2. I was going through this list:

http://www.freebsd.org/releases/7.2R/hardware.html#DISK

For some reason Freenas 8 won't let me add software raided disks into the iSCSI disk(direct to disk, not a file). The onboard raid isn't good as Freenas still detects the disks as individuals(I assume this is because the onboard raid is still software raid). Plus if the OS disks fail, I'm buggered....

Plan:

Multiple ESXi boxes mount the same iSCSI stores(NFS stores will come later too)

 

[survive]

Hi silver565,

Sure, I understand why you want hardware RAID....there's nothing wrong with what you are looking for and traditionally HW RAID is the way you would go about getting it.

If you can set aside what you think you want I would encourage you to give ZFS a long hard look. When you have some time I would encourage you to read the obligitory wikipedia link:

http://en.wikipedia.org/wiki/Zfs

and take a look at this presentation:

https://blogs.oracle.com/video/entry/becoming_a_zfs_ninja

I won't regurgitate the above information, but basically ZFS was written by Sun years ago to address a whole bunch of problems with traditional RAID. It's an industrial-grade filesystem that integrates volume management with other features like data checksumming & snapshots. Take a look at it as it solves almost every problem you are looking to address.

I don't know what hardware you are tying to use, but on-board (chipset) raid is really just software raid with a BIOS in front of it so you can boot from it. Neither AMD nor Intel chipsets are supported in FreeNAS which explains why your disks still show up as individual drives. If you use FreeNAS you really only need to worry about the config file, as long as you have a current copy of that you can recover from an OS failure in the time it takes to do a fresh install & restore the config (under 5 minutes if you don't have to burn the CD).

ZFS has the ability to create a special kind of filesystem-within-a-filesystem called a "zvol" that you can present over iSCSI that is direct to disk as you require.

One other thing...you can't present the *same* iSCSI volume to multiple systems without them being "cluster aware". Iscsi looks like a disk that's directly attached to the system so it (rightly) assumes that it has full control of that disk...if 2 systems write to the same iSCSI disk you will almost certainly corrupt the volume.

-Will

 

[silver565]

Ah thank you for that. This is a work thing. The boss is quite keen on iSCSI and I've been tasked with coming up with a decent solution.

ZFS after a skim read does seem quite nice. I'll have another read on Monday (Currently friday night here at the moment) and see what I can come up with.
I've got a test box beside me that I've been toying around with. I haven't used freenas since v7 though, so I'm still learning version 8 (ZFS was only experimental back with v 6 & 7)

Do you think ZFS will be mountable through the iSCSI service?


Hmmm... so multiple systems will corrupt the volume? That is interesting.. I had an iSCSI setup running, and 4 ESXi boxes added the disks fine. I'll have a google around for "cluster aware" and see if I can get freenas or ESXi to support that. Thank you for the heads up! I wouldn't have noticed otherwise. I hope it's possible, otherwise this idea of 4 ESXi machines using the same iSCSI stores goes right out the window. NFS would have to be the next option.


Thanks for your help. I will report back on Monday with the results of my ZFS test.

 

[survive]

Hi silver565,

You can create what's called a "zvol" which is a kind of ZFS filesystem that you can present directly over iSCSI:

http://www.freenas.org/images/resou...8.0.3_guide.html#__RefHeading__9148_381758029

ESXi is cluster aware, that's what allows you to use the shared storage via something like iSCSI....but think about what happened if you did that with plain old windows (not windows in a cluster)!

-Will