On 19/02/2013 19:42, Reindl Harald wrote:
Am 19.02.2013 20:24, schrieb Gordan Bobic:
> On 19/02/2013 19:05, Reindl Harald wrote:
>>
>>
>> Am 19.02.2013 20:02, schrieb Gordan Bobic:
>>>> what exactly do you need to align on the partitions?
>>>
>>> For a start, making sure your RAID implementation puts the metadata
>>> at the end of the disk, rather than the beginning.
>>
>> "my RAID implementation"?
>> LINUX SOFTWARE RAID
>>
>> and this is how the raid-partitions are looking
>> no problem since years
>>
>> Disk /dev/sda: 2000.4 GB, 2000398934016 bytes, 3907029168 sectors
>> Units = sectors of 1 * 512 = 512 bytes
>> Sector size (logical/physical): 512 bytes / 512 bytes
>> I/O size (minimum/optimal): 512 bytes / 512 bytes
>> Disk identifier: 0x0000ae2c
>> Device Boot Start End Blocks Id System
>> /dev/sda1 * 2048 1026047 512000 fd Linux raid autodetect
>> /dev/sda2 1026048 31746047 15360000 fd Linux raid autodetect
>> /dev/sda3 31746048 3906971647 1937612800 fd Linux raid autodetect
>>
>> [root@srv-rhsoft:/downloads]$ sfdisk -d /dev/sda
>> # partition table of /dev/sda
>> unit: sectors
>> /dev/sda1 : start= 2048, size= 1024000, Id=fd, bootable
>> /dev/sda2 : start= 1026048, size= 30720000, Id=fd
>> /dev/sda3 : start= 31746048, size=3875225600, Id=fd
>> /dev/sda4 : start= 0, size= 0, Id= 0
>
> That's the MD partition alignment, not the alignment of the FS space within the
MD device. The two are not the same.
maybe you should read older posts in the thread
Looking for what, exactly?
[root@srv-rhsoft:/downloads]$ tune2fs -l /dev/md1
[...]
This won't tell you the FS alignment against the raw underlying disk
sectors.
Blocks per group: 32768
This is sub-optimal in almost all cases except RAID1 or single-disk, as
I explained earlier.
Gordan