Re: Bug? Extremely slow loading of initrd if it has more than 4 extents on EXT4

[Felix Miata]

On 2013-05-16 13:57 (GMT+0200) Joschi Brauchle composed:

> I have a problem with booting openSUSE 12.3 from an ext2 filesystem
> using GRUB 0.97 as follows:

According to your Novell bug report, you're using an ext4 filesystem.

openSUSE's Grub 0.97 is exclusively "maintained" by openSUSE. Upstream hasn't 
maintained Grub Legacy for several years. EXT4 support in openSUSE's Grub 
0.97 would be entirely openSUSE's responsibility.

> If the initrd file uses **more than 4** extents on the ext2 filesystem,
> loading it takes "forever" on a recent Core2Duo system (i.e. up to ~60
> seconds). That is, grub prints:
> ------
> root (hd0,0)
> kernel ...
> initrd ...
> <flashing cursor for a long time, i.e. up to 60 seconds>
> ------
> and then continues booting normally.

> If the initrd file takes **4 or less** extents on the ext2 filesystem,
> the initrd is loaded in "no time" (i.e. faster than the eye can see).

> I originally reported the problem here:
> https://bugzilla.novell.com/show_bug.cgi?id=808611

> Is this a known problem with the grub ext2 driver?

I have many openSUSE installations, all using Grub Legacy, among them at 
least 10 12.3, and no more than one using EXT4. I just booted the last 12.3 I 
had previously booted, which is on EXT3, but uses the EXT4 kernel driver, as 
most kernels have been doing for at least several releases. Filefrag -v 
reports the currently booted kernel uses 11 extents. I suspect few of my 
others would be very much different, at least WRT use of more or less than 4 
extents. IOW, I'd expect all are using >4. The 11.4 kernel's initrd on the 
system I'm typing this from uses 100 extents on EXT3.

I cannot recall ever seeing the slowness you're reporting. However, I have no 
HDs with 4k sectors used for booting anything. All my HDs >.5TB are data only 
devices. Only one of my openSUSE installations could possibly be booting from 
EXT4. The majority, if not all, are booting either from EXT2 or EXT3.

Grub2 is the default bootloader for openSUSE 12.3, but does not automatically 
replace Grub Legacy for upgrade installations. If you want Grub2 on a system 
Grub Legacy system upgraded to 12.3 you need to install it with zypper or yast.
--
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