[haiku-development] Re: Slow Alpha Installation
- From: Nicholas Otley <nicholasotley@xxxxxxxxx>
- To: haiku-development@xxxxxxxxxxxxx
- Date: Thu, 10 Sep 2009 10:57:57 +0100
I did a test installation from the r33023 Alpha ISO to a USB pen drive
and it took over 4 hours!
I did it from within VMWare Fusion so I'm unsure of whether it is a
problem with Fusion or with Haiku yet.
I'll try to do the same again but from real hardware later today and
report back.
Cheers,
Nik
On 10 Sep 2009, at 11:44, Stephan Assmus wrote:
>
> On 2009-09-09 at 23:07:42 [+0000], Izomiac
> <haikulist@xxxxxxxxxxxxxxxx>
> wrote:
>> I recently installed the Alpha on real hardware using a CD. It
>> took a
>> very long time (I didn't keep track but probably well over half an
>> hour).
>> Fortunately, the reason is fairly obvious: I'm using a first
>> generation
>> SSD with extremely slow random write speeds. For this specific case,
>> it's a niche scenario that I honestly don't think any developer
>> should
>> waste their time with. I was well aware of the flaw when I bought
>> the
>> drive, but maintain that the benefits far outweigh the defect. That
>> said,
>> no drive is terribly fast at random writes; it's far slower than
>> sequential writting. So, forgive me if the filesystem doesn't allow
>> this, but during my wait a method for dramatically decreasing
>> installation time occurred to me. First, do a sector-by-sector
>> copy of
>> the installation media to the front of the partition. Next, expand
>> the
>> BFS volume to fill the partition. Finally, do makebootable and
>> whatever
>> else that's needed to make it a valid and bootable partition.
>>
>> Of course, the old method should be available, since one might want
>> to
>> use an existing BFS volume or tweak the filesystem options. No GUI
>> option is necessary, just use the old method for existing volumes
>> and the
>> proposed method for unformatted partitions.
>>
>> The speed benefit for an SSD like mine would be (maximum) 72
>> minutes down
>> to (minimum) ~5 seconds. For a normal harddisk with 4KB random write
>> speeds of
>> 3 MB/sec and sequential write speeds of 60 MB/sec, the difference
>> is ~3
>> minutes VS 8 seconds. I'm working based off of worst (4KB random
>> writes)
>> VS best (sequential) case scenarios. Obviously my Haiku installation
>> took less than half the maximum theoretical time, but I think the
>> real
>> world performance benefit on all drives would still be unignorable.
>>
>> The installation media would become the limiting factor, which is
>> probably already the case for CDs to magnetic disks, but other
>> types of
>> installations would greatly benefit. Unless, of course, the CD
>> filesystem is copied onto a ~500 MB ramdisk prior to booting (for
>> systems
>> with >=1GB of RAM)... It should even be faster overall since there's
>> less CD seeking for random files during the boot/install process.
>
> I don't know with what version of the alpha you have tested this,
> but very
> recently, I added unzipping a lot of the packages instead of having
> them
> already extracted on the image and doing a plain copy. This has sped
> up the
> installation process quite a lot especially towards the end. I have
> performed an installation in just under 20 minutes (which is of course
> still not as fast as it could be in theory). I am 100% sure the CD-
> ROM is
> the speed limiting factor here. If you didn't try with a very recent
> alpha
> image, it would probably be worth it to repeat it now, even if just to
> confirm the CD-ROM was more of a problem than your SSD. I expect
> there will
> be some random writes, when BFS updates directory B-Trees and
> indices. But
> there should still be a lot of sequential writes, since there is
> only one
> thread writing all the files sequentially.
>
> Best regards,
> -Stephan
>
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