NASLite Network Attached Storage

Databeestje,

what you are saying sounds worrying....

I have an adaptec 2400a (4port ATA) and it's been running for a week without problems so far. At least for this version there is no option from the BIOS based SMOR to turn the read cache totally off.

Are these problems mainly for SATA boards?

Any ideas on how the 3wave cards fair with our dear friend linux?.. (I usually use the LSI/MegaRaid cards, but even on the cheap (read: ebay) I have not found them less than 400.

Anyone want to by a Dell CERC 2610SA Raid Controller?.. Cheap?

I am not quite sure how the 4 port ATA would fair. however, if it uses the aacraid driver (which a lot of the adaptec boards do) I am suspecting a similar scenario. Ah, I found the link. http://linuxmafia.com/faq/Hardware/sata.html

Your card is special

In a good way though, Adaptec purchased DPT which made the ICP Vortex cards. This driver is regarded as good.

It's not that people have been unsuccesful in getting the aacraid cards (scsi or sata) to work. The only problem is performance. A raid 5 with the write cache disabled will get you close to 5MB/s on the scsi variants whilst the raid 1 and 0 is safe in all regards.

With the dead motherboards I referred to the Dell PowerEdge 2650 with the onboard Perc3/Si. Although even on the PowerEdge 2450 and 2/Si the problems were also existant.

The problem a number of people were having with the aacraid drivers and raid 5 arrays with write back cache enabled was that the firmware would get in a knot during a fsck at boot and thus the controller appeared "dead" to the OS and prevent booting further down the line. IIRC it could also be triggered using iozone.

This is very specific for the cards with the 100Mhz Intel 960 processor on the board. It was just not fast enough. At anything.

With regards to the 3Ware and LSI Logic cards I can say that over the past 6 years they have been extremely reliable even with regards to disk failures. I have over a TB on a 3ware controller under linux and half a TB on linux with the Megaraid 320-2E both are heavily used and I push about 400Mbps each night between both in a rsync. (limited by ssh).

Eventhough the old LSI Logic Megaraid cards also used the same Intel 100Mhz i960 processor it performed better and far more reliable. Faster, yes, but not as fast as a very cheap 3Ware 7000-8 and ata disks would be.

By a big margin. This also holds true for the LSI Logic Megaraid 150-4 and 150-6. I mean 23MB/s write performance under linux on 4 disks with write back caching is nothing to shout about. Read performance was up there at 100MB/s which is (probably) pci bus limited.

The quite a lot newer Sata 300-8X is mad though. It's doing over a 100Mb/s easily with the writeback cache on
The only problem with that card being that it only fits in a PCI-X slot. Which is a good thing.

The lsi cards do have a good upgrade path though. Buy a Megaraid 150-6 now, purchase a SAS controller or PCI-E version later on newer hardware, transplant the disks and everything " just works " because the on disk format is the same.

Hope this helps.

If you only need performance for a good price buy a Areca 1120 :p

Thanks for that databeestje.

This is my understanding as well.

I ve disabled writeback from the outset. BTW in the syslog I can see that the 2400A is recognised as an I2O board.
In my case, and I am sure for many in this forum, performance is not that much of an issue. What is required is more security from the failure of a single disk. I want to purely store my large video archive and stream to clients throughout the house.

No if I was to talk for database access, where performance is critical, then OK I can see the point about using writeback.

In any case after a week, I realised that the 830Gb RAID 5 array is alreadt fulll and I need something about twice the size..... which throws me towards an 8port 3ware card....

I realise this thread is almost two years old but I'd love to hear if the 100MB/s was on a box running NASLite? I have the same card and I'm getting 45MB/s on a PCI-X bus :/