Nortrek Posted May 26, 2015 Share Posted May 26, 2015 I got 2x 1TB disks i plugged in to my unRaid 6 sererver, and i see something have changed from some time back where i coul`d just click format on the disks. I got forced to preclear them first before adding them to the array, this is very good and i will use on new disks, but these two disks i trust so i woul`d be happy if i can skip this process ? Regards Nortrek Quote Link to comment
trurl Posted May 26, 2015 Share Posted May 26, 2015 I got 2x 1TB disks i plugged in to my unRaid 6 sererver, and i see something have changed from some time back where i coul`d just click format on the disks. I got forced to preclear them first before adding them to the array, this is very good and i will use on new disks, but these two disks i trust so i woul`d be happy if i can skip this process ? Regards Nortrek By "forced to preclear" do you actually mean that you didn't preclear them but unRAID cleared them itself? Regardless, a disk that will be added to a parity array (thus increasing the number of drives) must be clear (all zeros) so parity will remain valid. Quote Link to comment
Nortrek Posted May 26, 2015 Author Share Posted May 26, 2015 I got 2x 1TB disks i plugged in to my unRaid 6 sererver, and i see something have changed from some time back where i coul`d just click format on the disks. I got forced to preclear them first before adding them to the array, this is very good and i will use on new disks, but these two disks i trust so i woul`d be happy if i can skip this process ? Regards Nortrek By "forced to preclear" do you actually mean that you didn't preclear them but unRAID cleared them itself? Regardless, a disk that will be added to a parity array (thus increasing the number of drives) must be clear (all zeros) so parity will remain valid. I mean that when i added them to my server, the only option i can do is to clear them, and not go direcly to format as i used to do some months back when i added new disks. Ok, so there is not a way to skip this for disks that you kinda "trust" ? EDIT: I see it is 25% on those two new disks, is this for round 1 or is this % showing totaly for both disks ? Thank you for the quick answer. Quote Link to comment
trurl Posted May 26, 2015 Share Posted May 26, 2015 I got 2x 1TB disks i plugged in to my unRaid 6 sererver, and i see something have changed from some time back where i coul`d just click format on the disks. I got forced to preclear them first before adding them to the array, this is very good and i will use on new disks, but these two disks i trust so i woul`d be happy if i can skip this process ? Regards Nortrek By "forced to preclear" do you actually mean that you didn't preclear them but unRAID cleared them itself? Regardless, a disk that will be added to a parity array (thus increasing the number of drives) must be clear (all zeros) so parity will remain valid. I mean that when i added them to my server, the only option i can do is to clear them, and not go direcly to format as i used to do some months back when i added new disks. Ok, so there is not a way to skip this for disks that you kinda "trust" ? Thank you for the quick answer. The actual point of clearing a disk, whether you let unRAID do it or whether you use the preclear script, is to allow a drive to be added while maintaining parity. The "testing" functionality you get with the preclear script is just an added bonus. Letting unRAID clear a drive is not a test. Quote Link to comment
Nortrek Posted May 26, 2015 Author Share Posted May 26, 2015 Thank you for the good info, as you see i am not so much into this and it shows that i have more reading up to do about this. It is 30% so the speed does not seem to slow, but i can immagine it is very slower when i put in new 4TB disks. I will modify this post to solved, hopefully some other will search and use the information. Quote Link to comment
itimpi Posted May 26, 2015 Share Posted May 26, 2015 unRAID will always offer to clear a disk (with no option to bypass this) if you are adding it to an array that is already parity protected unless you have previously run the preclear script on it. I suspect the first time you were doing this was an initial configuration? unRAID does not need to clear a disk on initial configuration (or after a 'new config'). 1 Quote Link to comment
garycase Posted May 26, 2015 Share Posted May 26, 2015 As noted, to add a disk to a protected array it HAS to be cleared. As you've noticed, when you do this, the array is not useable until it clears the disk. The "preclear" script allows you to do this BEFORE you add it to the array ... and it will then be very quick when you add it => you'll just have to format the disk. Note that if you're adding a disk that you're already confident in, and don't really need to further test, you can use the pre-clear script with the -n option and it will just do the clear ... skipping the pre- and post- read stages. This takes about 1/4th the time of a full pre-clear cycle. Quote Link to comment
trurl Posted May 26, 2015 Share Posted May 26, 2015 unRAID will always offer to clear a disk (with no option to bypass this) if you are adding it to an array that is already parity protected unless you have previously run the preclear script on it. I suspect the first time you were doing this was an initial configuration? unRAID does not need to clear a disk on initial configuration (or after a 'new config'). But if your new config includes a parity disk then you will have to rebuild parity if you add a disk that is not clear. So you either maintain parity by adding a clear disk, or add an unclear disk and rebuild parity. Quote Link to comment
itimpi Posted May 26, 2015 Share Posted May 26, 2015 unRAID will always offer to clear a disk (with no option to bypass this) if you are adding it to an array that is already parity protected unless you have previously run the preclear script on it. I suspect the first time you were doing this was an initial configuration? unRAID does not need to clear a disk on initial configuration (or after a 'new config'). But if your new config includes a parity disk then you will have to rebuild parity if you add a disk that is not clear. So you either maintain parity by adding a clear disk, or add an unclear disk and rebuild parity. As far as I can see you are just repeating what I said in slightly different words? I agree that if you re doing a new configuration you will have to build parity if you include a parity disk as part of the configuration, but that is a different issue to doing a clear and the array is available while parity is being built. Quote Link to comment
trurl Posted May 26, 2015 Share Posted May 26, 2015 As far as I can see you are just repeating what I said in slightly different words?I was only intending to elaborate on your point for the benefit of the OP, who did not seem to be clear on all the implications of parity and how these things all relate to each other. Quote Link to comment
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