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Recently one of my drive's went bad in my RAID, and I'm replacing with a new drive. I used this answer to mirror the partition on my old drive for resyncing. But I'm concerned about the output. My drives are 4k sectors, did I do something wrong the first time around? 

Checking that no-one is using this disk right now ...
OK
Warning: partition 1 does not end at a cylinder boundary
Warning: partition 2 does not start at a cylinder boundary
Warning: partition 2 does not end at a cylinder boundary
Warning: partition 3 does not start at a cylinder boundary 
Warning: partition 3 does not end at a cylinder boundary
Warning: partition 4 does not start at a cylinder boundary

Disk /dev/sda: 121601 cylinders, 255 heads, 63 sectors/track
Old situation:
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sda1   *      0+     12-     13-    102400   fd  Linux raid autodetect
/dev/sda2         12+   1318-   1306-  10485760   fd  Linux raid autodetect
/dev/sda3       1318+   2623-   1306-  10485760   fd  Linux raid autodetect
/dev/sda4       2623+ 121600  118978- 955685088+  fd  Linux raid autodetect
New situation:
Units = sectors of 512 bytes, counting from 0

   Device Boot    Start       End   #sectors  Id  System
/dev/sda1   *      2048    206847     204800  fd  Linux raid autodetect
/dev/sda2        206848  21178367   20971520  fd  Linux raid autodetect
/dev/sda3      21178368  42149887   20971520  fd  Linux raid autodetect
/dev/sda4      42149888 1953520064 1911370177  fd  Linux raid autodetect
Successfully wrote the new partition table

Re-reading the partition table ...
If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes:  dd if=/dev/zero of=/dev/foo7 bs=512 count=1
(See fdisk(8).)
Rui F Ribeiro
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xenoterracide
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1 Answers1

3

Having partitions that don't end on cylinder boundaries might phase some touchy operating systems and their partitioning programs. Your disk only has Linux partitions, so I presume you're only using it under Linux; Linux doesn't care.

If your disk has 4kB sectors, then you will get better performance if your partitions are aligned to 4kB. This is fiddly to achieve after the fact, but fortunately, all your partitions have 4kB alignment already.

Gilles 'SO- stop being evil'
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