[Quindor]

I have been doing some research into which drives might be compatible with my Adaptec 5805 raid adapter, or any hardware RAID adapter for that matter.

In this search and my experience over the last years, RAID type disks do not exist for nothing. These disks are often picked from batches, better constructed, heavier and more robust to withstand 24H duty and thrashing around the disk. Also they often have tuned firmware to deliver the best possible results in a RAID and not so much in a desktop. And they sometimes have a different warranty period, compared to a desktop disk.

Desktop disks have been traditionally a lot cheaper but not always safe to you use in a (hardware) RAID array. Sometimes problems would surface immediately, and sometimes only after a while. This lead me to find out what could be the main cause of this. In my opinion it has to do with TLER / CCTL. Everything else isn't really needed to make your RAID controllers understand the drive better.

Let me try to explain :

Which action should a HDD take in a situation where it has a hard time reading or writing something :
Desktop disk - try unlimited times until success
RAID disk - try 7 seconds max, then report back it failed to read the requested sector

What do Controllers expect the disk to do :
Desktop controller - Wait for the disk to respond, hangup and halt operations until success
RAID controller - Wait max 8 seconds (often default value) then declare disk bad and evict/fail disk from raid set

Ideal situation :
RAID Controller with RAID disks. A disk develops a fault, tries for 7 seconds, then tells the RAID controller that it failed to read a sector. RAID controller acknowledges this and rebuilds sector from it's RAID, writes data to a different sector on the disks and marks the original sector as bad. RAID controller happy, Disk happy, no dropping disks!

As you can see, mixing a desktop disk with a raid controller can produce unwanted results. Disks will be dropped, while nothing is really wrong with it, etc. In the end, it will become almost impossible to rebuild the RAID array anymore. Over time (when disks inevitably start to develop minor faults) this problem will surface and gradually become worse.

It became known
It first came to light that any disk can do either, and that it's just a value in the firmware when WD leaked a tool with which this could be set. They quickly disabled the functionality in their newer revisions of firmware and drives, to try to keep selling their much more expensive RAID editions (50% increase in price, nothing in cost, good deal for them). There is a good topic over at the HardOCP forum which work and which don't. WDTLER changed to setting in such a way that it would survive a reboot, actually altering the firmware itself.

Breakthrough 1
But since the newest patches/SVN of smartmontools or smartctl, it's now possible to use SCT control to change the value the SCTECR (Error correction) is set to. Since this is done through SMART, any modern disk should support it. A big thank you goes out to r.gregory whom made this possible!

Breakthrough 2
It's even now possible, using most modern RAID controllers, to use these commands on disks inside of a hardware RAID. And that's where it got interesting! Because if we can manually set the Error control values, we could ensure that at least this problem will not bite us again in the future!

There is only a slight problem, and that is that the set value will be reset on every power cycle. Reboots mostly do NOT affect the value. Thus, running Windows or Linux, this is no problem, just create a script which sets it upon boot. Myself I run VMware ESX or ESXi on my servers and it posed a slight problem. My solution is a custom Fedora 12 USB bootstick, which boots in about 30 seconds, sets the value and automatically reboots. Pull the stick out during the reboot and the system boots from HDD with VMware on it. Problem fixed. :)

So the only thing left now is to find out which disks are compatible with setting this command, and which are not.

So, how do we test this.....
Your controller does not matter (RAID controllers are bit more tricky and need a different approach though, see the smartmontools website).

Windows users, download the windows installer. This is the newest 5.40 build. This gives you the smartctl executable, which we'll need. Users of other OS flavors will need to build their version from SVN, since the current binary versions do not yet have this functionality in it.

Smartctl can be used for many other things besides this. It can tell you much about the life of your disk or say the current temperature for monitoring purposes, etc. etc.

None of these tests below will touch your data.

When you have that installed, and for example the disk you wish to check is your "d:" drive, execute the following :

The Tests
smartctl -l scterc d:
If correct, this will give you the following feedback on a desktop disk

Quote

SCT Error Recovery Control:
Read: Disabled
Write: Disabled

Now we are going to try and change that value :

smartctl -l scterc,70,70 d:
If that works, you will see the following feedback :

Quote

Read: 70 (7.0 seconds)
Write: 70 (7.0 seconds)

To put it back to original values again, either turn off the power of your system, or run "smartctl -l scterc,0,0 d:"

Interesting tests are also if the value survives a reboot or even a power-cycle (from what I understand, it should not).

Since I think this information is needed for anyone trying to build a home RAID array, we should keep a sort of database in this topic, maybe something like this:

Brand      Type            Type2          Size      RPM      Revision      Firmware      Available    Default        Reboot      Powercycle
Samsung    HD154UI         F2EG           1.5TB     5400     -             1AG01118      Yes          Disabled       Stay        Lost
Samsung    HD203WI         F3EG           2.0TB     5400     -             1AN10002      Yes          Disabled       Stay        Lost
Samsung    HD103UJ         F1             1.0TB     7200     -             1A001110      Yes          Disabled       Stay        Lost

Brand      Type            Type2          Size      RPM      Revision      Firmware      Available    Default        Reboot      Powercycle
WD         WD360GD                        36GB      10000    00FNA0        35.06K35      No           -              -           -
WD         WD10EADS        Caviar Green   1.0TB     5400     00L5B1        01.01A01      Yes          Disabled       Stay        Lost
WD         WD2500BJKT      Scorpio Black  250GB     7200     ?             11.01A11      Yes          Disabled       Lost        Lost

Brand      Type            Type2          Size      RPM      Revision      Firmware      Available    Default        Reboot      Powercycle
Seagate    ST31500541AS                   1.5TB     5900     -             CC32          Yes          Disabled       Stay        Lost
Seagate    ST31500341AS    7200.11        1.5TB     7200     -             CC1H          Yes          Disabled       Stay        Lost
Seagate    ST31000333AS    7200.11        1.0TB     7200     PCB rev A?    CC1F          Yes          Disabled       Stay        Lost
Seagate    ST3250310NS     ES.2           250GB     7200     PCB rev A?    SN04          Yes          Enabled (6s)   N/A         N/A

Anyone willing to help and submit, much appreciated! Myself I would really like to know the results for the Samsung F3 2TB HD203WI EcoGreen disks!

Update: Thank you all for submitting! Keep them coming! :D

This post has been edited by Quindor: 01 May 2010 - 05:42 PM

[discjet]

Quindor, on 12 March 2010 - 04:48 PM, said:

Now we are going to try and change that value :

smartctl -l scterc d:

I suppose that should have been: smartctl -l scterc,70,70 d:

Anyway, here's data for 2 drives:

---------------

Model Family: Western Digital Raptor family
Device Model: WDC WD360GD-00FNA0
Serial Number: WD-WMAH91637100
Firmware Version: 35.06K35
36 GB, 10000 rpm

device does not support SCT Commands

---------------

Model Family: Seagate Barracuda LP
Device Model: ST31500541AS
Serial Number: 5XW00B87
Firmware Version: CC32
1500 GB, 5900 rpm

SCT capabilities: (0x103f) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.


Reboot: setting stays
Power off: resets back to disabled
(Drive is in esata box with its own power supply & switch, shutting down *pc* makes hd spin down, but setting stays as long as the hd is powered by the external box)

[continuum]

Quote

ut, doing closer research this is only because of one single setting : TLER / CCTL / etc.

Just to clarify... It's more than that. Much more in terms of internal firmware tweaks, and some often have physical changes to permit better vibration tolerance. However, you are partially correct in that error recovery period is one of the more important reasons. :)

(Areca implies some of this in their HDD compatibility list)

[Quindor]

Edited the post. Should have been ",70,70" indeed.

Also edited the part where it states that there is no other difference. That was a bit of a too harsch statement. Setting this value does not give you a RAID drive in firmware or hardware (more durable, specefically tuned), it only resolves not being able to use the drive in a RAID. Quite right you are.

[sireddie]

I'm also after the information regarding the 2T Samsung drives. I will probably just get them in a week or so and give it a go.

Quindor, on 13 March 2010 - 12:48 AM, said:

My solution is a custom Fedora 12 USB bootstick, which boots in about 30 seconds, sets the value and automatically reboots. Pull the stick out during the reboot and the system boots from HDD with VMware on it. Problem fixed. :)

I'm sort of in the same boat as I'm using a hardware RAID card with a Windows OS. This means I will have to run a Linux version of the tool (for hardware RAID support) and then reboot before loading Windows.

I'd be forever grateful if you would like to share a copy of your USB stick if you don't mind. I could then edit the command to suit my setup.

Thanks

[Quindor]

sireddie, on 17 March 2010 - 01:40 AM, said:

I'm also after the information regarding the 2T Samsung drives. I will probably just get them in a week or so and give it a go.



I'm sort of in the same boat as I'm using a hardware RAID card with a Windows OS. This means I will have to run a Linux version of the tool (for hardware RAID support) and then reboot before loading Windows.

I'd be forever grateful if you would like to share a copy of your USB stick if you don't mind. I could then edit the command to suit my setup.

Thanks

My 7x 2TB samsung disks should arrive tomorrow. Sadly, I did not want to wait any longer for anyone else to test it. ;)

I will certainly share my experience with them, maybe post some benchmarks, etc. (I'll make a different topic for that).

Sharing my bootstick. Hmm, I'll have a go at that. I'll make a backup using "DD" and then zip it to see how big it becomes. Off course, it will only be useful if your using an adaptec card (2 and 5 series). Otherwise it's almost easier to create a new one from scratch, integrate your drivers and admin console (mine boots the adaptec agent so I can connect to it from a different host to manage the adaptec itself, which cannot be done from VMware).

Don't expect too much from it. It's quite a crude installation. Just a full install, which I set to runlevel:3 to not boot the graphical UI and then run some scripts in the background and reboot again. Oh, and I also compiled the newest SVN of smartctl on there. That worked for me, so I stuck with it!

What kind of raid card are you using?

[sireddie]

Well someone has to be the first right ;)

I'm afraid I have some catching up in the Linux space and would have issues doing half of what you mentioned above :S

I'm using a Dell PERC 5/i card (rebranded LSI MegaRAID card) that should work fine with the smartmontools. I tried one of the Linux Live CD's yesterday and it seems to be recognizing the card, but I'm having issues getting the commands to work. I know the ERC commands won't work, but I kept on getting errors just trying to query the HDD connected to the card. I guess I'll have to look into that a bit more.

I'm thinking that as long as Greg's ERC version of smartmontools is compiled and loaded onto a bootable live distro, that should suffice. I might be wrong as I'm only speculating.

Anyways, I would appreciate if you could upload an image of the USB stick somewhere (or PM me for e-mail) so I could give it a go.

Thanks!

[Quindor]

sireddie, on 17 March 2010 - 11:33 PM, said:

Well someone has to be the first right ;)

I'm afraid I have some catching up in the Linux space and would have issues doing half of what you mentioned above :S

I'm using a Dell PERC 5/i card (rebranded LSI MegaRAID card) that should work fine with the smartmontools. I tried one of the Linux Live CD's yesterday and it seems to be recognizing the card, but I'm having issues getting the commands to work. I know the ERC commands won't work, but I kept on getting errors just trying to query the HDD connected to the card. I guess I'll have to look into that a bit more.

I'm thinking that as long as Greg's ERC version of smartmontools is compiled and loaded onto a bootable live distro, that should suffice. I might be wrong as I'm only speculating.

Anyways, I would appreciate if you could upload an image of the USB stick somewhere (or PM me for e-mail) so I could give it a go.

Thanks!

Hahaha, my linux skills are at noobish levels at best! I just try until it works. :P

Again, I can put the zipped DD files of the stick on my FTP server for you if you really wish. But you will need an identical USB stick (exactly identical, in my case 8GB) and then the stuff I made only works for ADAPTEC cards, your PERC does not work in that way. So it would be completely useless for you..... The stick I have now is also a very crude big install, etc.

My best bet for you would be, download a debian ISO (Debian is easier then fedora in my opinion, but fedora is best for adaptec), install that to your USB stick. Compile the svn of smartmontools (apt-get install subversion gcc automake "and euhm c++ modules for gcc") then follow the instructions on the smartmontools homepage. And then try to use smartctl using the megaraid switch (The Dell PERC 5/i is an OEM version of a LSI card (exact type not in my head right now).

Sorry to disappoint you in this. Also took me 2 days to get it working for me, but believe me when I say my stick will not work for you. When you figure it out, it's not that hard though....

To everybody else, come on people, submit those specs! Single disks connected to motherboard controllers are fine, etc.

This post has been edited by Quindor: 18 March 2010 - 06:41 AM

[sireddie]

Thanks for the info and tips. I'll give it a go when I have some time to play around with it. Don't bother with the FTP.

Did you end up getting your new Samsung drives? Did they play nice with CCTL/ERC?

[Quindor]

sireddie, on 18 March 2010 - 06:33 PM, said:

Thanks for the info and tips. I'll give it a go when I have some time to play around with it. Don't bother with the FTP.

Did you end up getting your new Samsung drives? Did they play nice with CCTL/ERC?

Yes and yes, but busy at a client right now. Will add info to this topic and fill my other topic as soon as I get a bit of time!