Hi All,

 

I've just started using unRaid and looks great so far.  I have 5.05 installed and an array up and humming along.  I finally installed unmenu, and quickly noticed I have the HPA issue on all but one of my drives.  I have read a ton of the threads out there and I think I have a bit of overload.  What I couldn't seem to find answered (but thought I remember reading about) is about fixing the drives. 

 

Drives:

parity = 4tb

drive 1-5 = 3tb

cache = 128tb

 

and all but drive 4,5 is just slightly off.  I'm about to add a new 4tb drive and realize i'll need at least the parity drive fixed before that happens.

 

only drive 1-3 have data on them and drive 3 doesn't have that much.

 

MB: Gigabyte G31M-ES2L rev2

 

What I think I understand is that I'll need to correct each drive one by one.  Correct one and then rebuild?  Is that correct?  I'm assuming when I fix a data drive that parity will need to be rebuilt. 

 

My current though is to empty drive 3 and remove drive 3-5 from the array and shrink it.

Then fix the HPA issues on those drives

Then remove and fix the parity drive and rebuild parity

Then remove and fix drive 1, rebuild, drive 2, rebuild

 

Am I on the right track?  suggestions, comments? 

 

Thanks in advance!

 

.chris.

First make sure that the MB is not actively adding HPA to your disks. The board must have HPA off by default in BIOS. If HPA is on by default then the board is not suitable for unRAID. Check for a BIOS update.

What's HPA?

 

First, look in your BIOS for "Backup BIOS Image to HDD" ... and be sure this is DISABLED.

 

That prevents any future drives from getting an HPA.

 

Second, the simplest thing to do is (AFTER ensuring you've disabled that option) to simply use the new 4TB drive as parity, and not bother with the other drives.  An HPA doesn't hurt anything; and it occupies such a trivial amount of space it's irrelevant.    Not really worth the bother of fixing the drives and rebuilding them (one-at-a-time) ... which is basically the process you'd have to follow.

 

I would (a) replace the parity drive with the new 4TB drive [be SURE you have good parity before doing that];  then (b) remove the HPA from the old parity drive, and then add it as a new data drive;  and then simply consider yourself done.    You're never going to use the 3TB drives as parity drives; and when you eventually replace them, the replacement drive won't have the issue ... so the trivial amount of space you'd gain isn't really worth the bother.  [You don't really need to bother removing it from the old parity drive either; but since it has no data, and you're going to clear it anyway, you may as well.]

 

 

 

 

What's HPA?

"Host Protected Area"...its a small area of a hard drive which is reserved. It deducts from a drive's overall disk storage.  Some systems use it to keep track of 'low level' system information.

Its not  a lot of room, but if you end up in a 'mixed' environment (for example, all 3TB drives, but with some drives having and other drives not having HPA) the disks will show two different sizes when queried.  In that case, the PARITY disk for sure must NOT have HPA.  Otherwise, Parity is effectively smaller than a data drive without HPA.

What's HPA?

"Host Protected Area"...its a small area of a hard drive which is reserved. It deducts from a drive's overall disk storage.  Some systems use it to keep track of 'low level' system information.

Its not  a lot of room, but if you end up in a 'mixed' environment (for example, all 3TB drives, but with some drives having and other drives not having HPA) the disks will show two different sizes when queried.  In that case, the PARITY disk for sure must NOT have HPA.  Otherwise, Parity is effectively smaller than a data drive without HPA.

 

Thanks for that Dale. How can i check my drives?

First, look in your BIOS for "Backup BIOS Image to HDD" ... and be sure this is DISABLED.

 

That prevents any future drives from getting an HPA.

 

Second, the simplest thing to do is (AFTER ensuring you've disabled that option) to simply use the new 4TB drive as parity, and not bother with the other drives.  An HPA doesn't hurt anything; and it occupies such a trivial amount of space it's irrelevant.    Not really worth the bother of fixing the drives and rebuilding them (one-at-a-time) ... which is basically the process you'd have to follow.

 

I would (a) replace the parity drive with the new 4TB drive [be SURE you have good parity before doing that];  then (b) remove the HPA from the old parity drive, and then add it as a new data drive;  and then simply consider yourself done.    You're never going to use the 3TB drives as parity drives; and when you eventually replace them, the replacement drive won't have the issue ... so the trivial amount of space you'd gain isn't really worth the bother.  [You don't really need to bother removing it from the old parity drive either; but since it has no data, and you're going to clear it anyway, you may as well.]

 

Thanks Gary!  I was concerned that having HPA on data drives may cause problems with parity, but sounds like it won't and I'll just ignore those.  Unfortunately I updated the bios to the latest and still don't see an option to change /disable it.  And looking through the forums, it appears this is not a good board to build off for this reason. I guess I'll need a new MB.  :-( 

 

Thanks again Gary.

Interesting.  It's listed in the "Advanced Features" section of my BIOS ... says "Backup BIOS Image to HDD"  with choices of "Enabled" or "Disabled".  It was not listed originally, but was added to a later BIOS version.    But if you're using the F10 version of the BIOS for that board and it's still not available, then it seems Gigabyte never added that capability.

 

One "good" thing is that it's not likely to add an HPA to your new 4TB drive.  Just be sure it's not on a low-numbered SATA port.  My understanding of the way the Gigabyte BIOS implements the "backup the BIOS" feature is that it looks at the drives on the chipset ports ... e.g. SATA 0, then SATA 1, then SATA 2, etc. ... and if it finds a drive with an HPA it stops.    So, since you already have an HPA on several of your drives, it's not likely it will add one to your new drive as long as you don't plug it into the lowest port #.    So you can safely do as I suggested earlier -- just use the new drive as parity; and don't worry about any of the others.

 

... But double-check your BIOS to be sure you used F10 and that it doesn't have the option to disable this "feature".  Clearly that would be the best thing to do.    And of course if/when you decide to upgrade, get a board that doesn't do this !! 

Interesting.  It's listed in the "Advanced Features" section of my BIOS ... says "Backup BIOS Image to HDD"  with choices of "Enabled" or "Disabled".  It was not listed originally, but was added to a later BIOS version.    But if you're using the F10 version of the BIOS for that board and it's still not available, then it seems Gigabyte never added that capability.

 

One "good" thing is that it's not likely to add an HPA to your new 4TB drive.  Just be sure it's not on a low-numbered SATA port.  My understanding of the way the Gigabyte BIOS implements the "backup the BIOS" feature is that it looks at the drives on the chipset ports ... e.g. SATA 0, then SATA 1, then SATA 2, etc. ... and if it finds a drive with an HPA it stops.    So, since you already have an HPA on several of your drives, it's not likely it will add one to your new drive as long as you don't plug it into the lowest port #.    So you can safely do as I suggested earlier -- just use the new drive as parity; and don't worry about any of the others.

 

... But double-check your BIOS to be sure you used F10 and that it doesn't have the option to disable this "feature".  Clearly that would be the best thing to do.    And of course if/when you decide to upgrade, get a board that doesn't do this !! 

 

Thanks gary.  I'm pretty sure I had the latest bios.  I'll check again, I could have missed it.    I ditched the board and got a supermicro x9scm-iif, but intend to use the Gigabyte board as a backup / preclear machine.

Interesting.  It's listed in the "Advanced Features" section of my BIOS ... says "Backup BIOS Image to HDD"  with choices of "Enabled" or "Disabled".  It was not listed originally, but was added to a later BIOS version.    But if you're using the F10 version of the BIOS for that board and it's still not available, then it seems Gigabyte never added that capability.

 

One "good" thing is that it's not likely to add an HPA to your new 4TB drive.  Just be sure it's not on a low-numbered SATA port.  My understanding of the way the Gigabyte BIOS implements the "backup the BIOS" feature is that it looks at the drives on the chipset ports ... e.g. SATA 0, then SATA 1, then SATA 2, etc. ... and if it finds a drive with an HPA it stops.    So, since you already have an HPA on several of your drives, it's not likely it will add one to your new drive as long as you don't plug it into the lowest port #.    So you can safely do as I suggested earlier -- just use the new drive as parity; and don't worry about any of the others.

 

... But double-check your BIOS to be sure you used F10 and that it doesn't have the option to disable this "feature".  Clearly that would be the best thing to do.    And of course if/when you decide to upgrade, get a board that doesn't do this !! 

 

Thanks gary.  I'm pretty sure I had the latest bios.  I'll check again, I could have missed it.    I ditched the board and got a supermicro x9scm-iif, but intend to use the Gigabyte board as a backup / preclear machine.

 

The Gigabyte board will add HPA to any disk attached. Do not use it for pre-clears.

The Gigabyte board will add HPA to any disk attached. Do not use it for pre-clears.

 

While I agree it's safest to just not use this board for pre-clearing; it is NOT true that it adds an HPA to any attached disk.  Once it "sees" an HPA, it does not create another BIOS backup to subsequent disks, which is what causes the HPA.    I've confirmed this on 3 different Gigabyte motherboards, including in particular the board discussed here.

 

If you simply leave an old hard drive attached to SATA-0 with an HPA, it will not create HPAs on any other attached disks.