I just ghosted a hard drive containing Win7 and OS11.4 to a new WD hard drive with 4K byte alignment. WD provides a tool to align Win7 (and it apparently needed it) but reports other partition types (Ext3/4) as corrupt. Here’s the question: is there a way to get 4K byte alignment in Ext3/4 after installation, or do I need to reinstall? Is there an authoritative page on this for OpenSuSE/Kubuntu?
Thanks!
PattiMichelle
After installation is too late. You have to align it at the partitioning stage. Do a search for 4kB block alignment linux.
Hi
I would also ensure that you have the latest firmware on the drive as
well, and make sure you have a backup drive for your data.
–
Cheers Malcolm °¿° (Linux Counter #276890)
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Thanks - I will search. I was hoping for a tool that would do the alignment - Acronis does it for NTFS…
>After installation is too late. You have to align it at the partitioning stage.
>
Ahhh… maybe that explains why Acronis WD-aligh could not align my NTFS partition that’s within the extended partition? (It did ok in the Win7 system partition) Do all the current flavors of Linux do the correct (4K) byte alignments during a standard install? (I didn’t find any information more recent than 2010) I wonder if gparted is getting close to dealing with this problem?
I don’t think that all Linux distro installers are 4kB savvy yet, but don’t quote me.
PattiMichelle wrote:
>> After installation is too late. You have to align it at the
> partitioning stage.
>
> Ahhh… maybe that explains why Acronis WD-aligh could not align my
> NTFS partition that’s within the extended partition? (It did ok in the
> Win7 system partition) Do all the current flavors of Linux do the
> correct (4K) byte alignments during a standard install? (I didn’t find
> any information more recent than 2010) I wonder if gparted is getting
> close to dealing with this problem?
There is no way that Linux or any other installer can automatically deal
with all WD drives, because some of them lie about their block size.
You need to be very careful about the exact model number. Google for wd
4k block size problem or somesuch and you will find lots of info.
I wonder if gparted is getting close to dealing with this problem?
Well, sort of. I have quite a number of those WD - xx EARS drives in use and I do format all of them with parted before installing any OS. The trick is to start the first partition with sector 64 (63 would be the default) and then make every partition a multiple of 8 blocks (yes, parted believes that the drive has 512 byte blocks).
Thank you everyone for the discussion!!
OK, so the linux install won’t install correctly without knowledgable user intervention, yes? I’ve taken to installing multiple OS’s, and lately I keep the Win7 bootloader… I guess I could partition with Win7’s partitioner (I don’t think it’s as powerful as parted). Correct me if I’m wrong, but I think if Win7 already has put its 4K-aligned partition in-place on a HD, then subsequent partitions are forced by parted to be 4K aligned? When I’ve created partitions in parted (during install) and I’ve only just give size roughly (like 12.9GB) - I’m wondering if parted translates that into 512B-sized numbers, like 1291776B or if it is smart enough to make that size = 1290240B (divisible by 4K) so that the next partition is 4K aligned? I just don’t know enough about hard drive bytestacking to know whether this is too simplistic.
Maybe I have to declare every partition’s size (starting and ending) in parted to be a number divisible by 4096? Wait, doesn’t parted ask for “cylinders?”
Does starting a root partition at 64B really force the entire drive (all subsequent partitions) to be 4K aligned?
OK, so the linux install won’t install correctly without knowledgable user intervention, yes?
correct.
Correct me if I’m wrong, but I think if Win7 already has put its 4K-aligned partition in-place on a HD
You could use parted to check that Win7 has created properly aligned partitions.
…then subsequent partitions are forced by parted to be 4K aligned?
No. They will be properly aligned when every subsequent partition has a size which is a multiple of 8 (512B) sectors. Parted does not know about the internal 4K blocks of the drive and it displays the number of 512B sectors. To the outside world the drive pretends to have 512B blocks. This was made by the manufacturer to make the drives “compatible” but the effect is a misalignment of the partitions in most cases.
When I’ve created partitions in parted (during install) and I’ve only just give size roughly (like 12.9GB) - I’m wondering if parted translates that into 512B-sized numbers, like 1291776B or if it is smart enough to make that size = 1290240B (divisible by 4K) so that the next partition is 4K aligned?
No. It is manual work. You must enter the desired partition size in numbers of 512 Byte sectors and these numbers must divide by 8. Use the ‘unit s’ command to make parted display sector counts. This is an example:
GNU Parted 2.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) unit s
(parted) print
Model: ATA WDC WD10EARS-00Y (scsi)
Disk /dev/sda: 1953525168s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 64s 4112639s 4112576s primary ext2 boot, type=83
2 4112640s 963899999s 959787360s primary ext4 type=83
3 963900000s 974182399s 10282400s primary linux-swap(v1) type=82
4 974182400s 1953523711s 979341312s primary ext4 type=83
(parted) unit chs
(parted) print
Model: ATA WDC WD10EARS-00Y (scsi)
Disk /dev/sda: 121601,80,62
Sector size (logical/physical): 512B/512B
BIOS cylinder,head,sector geometry: 121601,255,63. Each cylinder is 8225kB.
Partition Table: msdos
Number Start End Type File system Flags
1 0,1,1 255,254,62 primary ext2 boot, type=83
2 256,0,0 59999,254,62 primary ext4 type=83
3 60000,0,0 60640,12,43 primary linux-swap(v1) type=82
4 60640,12,44 121601,57,55 primary ext4 type=83
Every partition size divides by 8. Can you see that parted detects a logical/physical sector size of 512B? It’s up to you to take the hidden internal block size into account.