Re: Feature request: Add flag for assuming a new clean drive completely dirty when adding to a degraded raid5 array in order to increase the speed of the array rebuild
From: Jaromír Cápík <hidden>
Date: 2022-01-14 14:10:36
Hello Roger.
quoted
Also, grow differs in the fact that blocks get moved around hence the writes.Of course, but even of that the speed was poor :]
Just for info, I just tried to DD data on the second (faster) hardware from one RAID drive to an empty one with MD offline and the transfer speed is the following (sorry for the czech locale :) ... 25423+0 záznamů přečteno 25422+0 záznamů zapsáno 26656899072 bajtů (27 GB, 25 GiB) zkopírováno, 105,227 s, 253 MB/s 25903+0 záznamů přečteno 25902+0 záznamů zapsáno 27160215552 bajtů (27 GB, 25 GiB) zkopírováno, 107,235 s, 253 MB/s 26386+0 záznamů přečteno 26385+0 záznamů zapsáno 27666677760 bajtů (28 GB, 26 GiB) zkopírováno, 109,245 s, 253 MB/s as you can see, the write speed really matches the speed from the drive datasheet, so ... why the sync speed was 100MB/s only when the CPU load was low? Can you explain that? Thanks, Jaromir