January 31, 201115 yr Just getting my Adaptec 2805 up and running and had a couple questions for guys running Adaptec cards and/or the 2-series in general. I've got 6 disks plugged in to the 6 headers on my mobo and when I run preclear through them I get a fairly consistent ~100MB/s write speed. When plugged in via my adaptec card, I'm seeing a consistent 50MB/s write speed. The disks are setup as JBODs so the actual device shouldn't be doing anything. I don't think it's the motherboard an issue with bandwith because I can run 3 preclears at the same time and get the same 50MB/s write speed on each of them. I'm using all WD20EARS disks (staggered purchases, etc...) and if I swap headers I see the normal rate. Doing some digging, it appears that Adaptec is endorsing a newer version of the aacraid module than ships with unraid. My question to Adaptec owners is: what does your preclear speed look like? have you taken their advice and manually upgraded the module? If so, what version? What speed do you see on preclear?
January 31, 201115 yr My question to Adaptec owners is: what does your preclear speed look like? have you taken their advice and manually upgraded the module? If so, what version? I do not have one of these cards but did want to comment on the above. Unless you build a new Kernel I do not think that you will be able to update the drive for this card. Send a request to Lime Tech about the updated drive with links to everything you found and the updated driver may be included with version 5.0beta3 or 5.0beta4.
February 3, 201115 yr Author More digging -- 5.0b3 has the kernel Adaptec recommends (2.6.36). I installed 5.0b3 but had a bit of a nightmare (4k aligned is the default setting and I could have lost my array if I had not thought better of manually adding my disks to the array). I'll give it a go again next week when I have more time. I'm starting to think most of this is moot because even though preclear was half the speed, when I added the disks to the array and started testing them they were slightly faster than via the mobo headers. My average write was 23MB/s on the mobo (over samba) vs 26MB/s on the adaptec drive. These were both clean, empty drives using the same exact 20 GB file. Likewise my read speed over samba is about 42MB/s for the mobo and 44MB/s for the adaptec card.
February 5, 201115 yr More digging -- 5.0b3 has the kernel Adaptec recommends (2.6.36). I installed 5.0b3 but had a bit of a nightmare (4k aligned is the default setting and I could have lost my array if I had not thought better of manually adding my disks to the array).I don't think that is true. ... the setting is used only if the disk does not have an existing MBR or valid preclear-signature. (in other words, an empty or foreign disk) If the disk is already partitioned from a prior version of unRAID, it works as it was, and the partition is unchanged. I'll give it a go again next week when I have more time. I'm starting to think most of this is moot because even though preclear was half the speed, when I added the disks to the array and started testing them they were slightly faster than via the mobo headers. My average write was 23MB/s on the mobo (over samba) vs 26MB/s on the adaptec drive. These were both clean, empty drives using the same exact 20 GB file. Likewise my read speed over samba is about 42MB/s for the mobo and 44MB/s for the adaptec card. The speeds sound fine.
February 7, 201115 yr Author More digging -- 5.0b3 has the kernel Adaptec recommends (2.6.36). I installed 5.0b3 but had a bit of a nightmare (4k aligned is the default setting and I could have lost my array if I had not thought better of manually adding my disks to the array).I don't think that is true. ... the setting is used only if the disk does not have an existing MBR or valid preclear-signature. (in other words, an empty or foreign disk) If the disk is already partitioned from a prior version of unRAID, it works as it was, and the partition is unchanged. What happened for me was I put 5.0b3 on my second thumbdrive and restarted the machine. Initially when it came up there were no drives listed and I was just about to go to the drive assignment screen before I thought better of it. I tabbed around on the settings a bit and found the 4k-aligned setting was enabled. I switched it to the non-4k aligned, rebooted and the whole array showed up on the device screen. I decided against starting the array and then rebooted with my 4.7 thumbdrive. That was the extent of my 5.0b3 run. I'm happy with the speed of the disks in realworld usage (even if the preclear is 1/2 the speed). Once I summon the courage to run 5.0b3 again I will do a little more testing.
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