Re: 3 way mirror

[Reindl Harald <h.reindl@thelounge.net>]

Am 11.09.22 um 13:35 schrieb Gandalf Corvotempesta:
> Il giorno dom 11 set 2022 alle ore 12:52 Reindl Harald
> <h.reindl@thelounge.net> ha scritto:
>> just throw it out of the array - on a RAID 1 with two disk you have
>> still redundancy and i won't trust a disk which recognized that it has
>> errors on it's own
> 
> Why ? if it's just a single sector, the rest of the disk could be used
> properly until the replacement.

i simply don't trust drives which have thrown errors
you don't lose anything when you push it out of the array

>> what's the point of "can i delay" when you have no other options? :-)
> 
> The option is: i've ordered the new disk, it should arrive this thursday.
> If i'm still on the safe side, i'll wait, if not, i'll replace with
> the first disk I have here, even if slower

you are clearly on the safe side with 3 mirrors and every rebuild wears 
out the remaining drives, 1 out of the 3 would be enough since they hold 
identical data

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

the only thing one should think of: are all 3 drives identical types 
with identical age - then it's more likely that they fail all within a 
short time

that's why i try to mix different disks in a mirror to avoid failing 
both sides of a mirror due firmware-error or a charge of bad disks

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

as i replaced my HDD to SSD i removed two drives out of my RAID10, as it 
didn't boot exchange two of them

so at that point 1 mirror of each stripe was a HDD and one a new SSD, 
after one year i replaced the remaining two disks

2 x 850 EVO 2TB
2 x 860 EVO 2TB

/dev/sda: GB Written: 72.020
/dev/sdb: GB Written: 69.709
/dev/sdc: GB Written: 91.367
/dev/sdd: GB Written: 94.134

pretty impossible that both sides of the same mirror will fail within a 
few hours