gmane.linux.general.linux-users

Linux and EFI

David A. Bandel — 2013-05-19T01:55:46

I guess the biggest challenge I've faced lately is the EFI boot on my
notebook.  It may be possible to backup to a BIOS boot, but as this seems
to be another "trend" M$ is railroading manufacturers into, I decided to
set it all up.

At first I tried GRUB.  That didn't go so well.  grub-efi is definitely not
ready for prime time.  At least, all I can ever seem to get is a
grub-rescue screen with grub-efi.  Not really a problem, I run lilo on all
my servers (despite LPI's decision to dump it on exams and only test GRUB).

So I am running elilo on my laptop and it works OK.  But I can't remote
boot it as I seem to have to walk it through the bootup (but at least it
does boot up).

Guess my question is, anyone know if there's going to be a way to get a
certified boot kernel that the EFI stuff will be happy with? Or a way to
create one (that would be even better)?

Ciao,

David A. Bandel

Re: OT: Questions about installing an SSD into my laptop

Rick Bowers — 2013-05-19T01:45:09

Thank you, Michael. I appreciate your response and the information 
you provided.

~Rick

Re: OT: Questions about installing an SSD into my laptop

Rick Bowers — 2013-05-19T01:42:02

Thank you, Vu. That is good information.
One of the things I wasn't able to determine was which version of 
SATA the drive(s) supported.  Now I know.
Can I assume a SATA-3 drive is backward compatible with my SATA-2 laptop?

~Rick

Re: OT: Questions about installing an SSD into my laptop

Vu Pham — 2013-05-18T22:03:23

I often use Crucial SSDs, but recently my notebook's drive failed and I 
found the SSD Samsung Pro Series 256G (MZ-7PD256BW ) has a lot of good 
reviews so I tried it. So far so good. No problems with Windows 7 or Linux.

The Samsung SSD is SATA3. Your Hitachi drive is SATA2, so I guess your 
notebook supports only SATA2. If so, even you do not gain by having your 
drive SATA3, but moving from mechanical drive to SSD is a big gain already.

I think Samsung has 5-year warranty for the Pro-series SSDs . When I 
bought my drive from Newegg, it is said to have 3-year warranty, but 
Samsung site says it has 5-year warranty. I just looked up your model 
and it has 3-year warranty. If warranty time is an important factor to 
you, then you may consider looking at the Pro series.

Vu

Re: OT: Questions about installing an SSD into my laptop

Michael Hipp — 2013-05-18T18:24:14

There shouldn't be any compatibility problems with your laptop. The new 
drive is thinner (0.28" vs 0.4") so it is possible (tho very unlikely) 
this could cause some mounting problems.

I'm going to suggest you plan on doing a full re-install of Win7 on the 
new drive rather than trying to migrate the older install. I've tried a 
couple of direct migrations. Some cases the migration worked fine but 
with no perceptible increase in speed, in others it cause the system to 
become unstable. Of course, be sure to copy off all data and 
configurations you need from the old drive.

Stay away from Win8. In the very least wait to see how Win8.1 turns out 
this fall.

Personally I'm a fan of the Intel SSDs, they seem to have a really good 
reputation for reliability and performance. But I have no real data with 
which to prefer it over the Samsung.

I've been migrating all my important systems to SSDs and definitely have 
not regretted it.

Michael


On 2013-05-18 12:50 PM, Rick Bowers wrote:

OT: Questions about installing an SSD into my laptop

Rick Bowers — 2013-05-18T17:50:39

Hi all,

I'm looking to possibly replace my existing hard drive with an SSD 
drive. In spite of googling for information, I'm still confused 
regarding suitability. Folks on this list seem knowledgeable in these 
matters so I'm asking for some guidance here.

I have an HP G60-642NR laptop. It came with the following Hitachi drive:
http://reviews.cnet.com/internal-hard-drives/hitachi-travelstar-7k500-hts725032a9a364/4507-9998_7-33875493.html

I am considering this Samsung drive:
http://www.adorama.com/SSG7TD500BW.html?utm_term=Other&utm_medium=Shopping%20Site&utm_campaign=Other&utm_source=pgrabl

My basic questions are:
- Are these drives compatible? HP.Com gives me no guidance wrt 
upgrading the drive in my laptop
- Should I look at other drives? Which ones?
- Price in a big consideration -- is this price reasonable for a 
500GB drive (I've looked at Pricewatch.com and it seems to be in line.
- What other considerations should I evaluate?

I'm currently running Windows 7 but am looking to upgrade this to 
Wi

Re: [OT]: creating cheat sheets

Lonni J Friedman — 2013-04-26T19:17:04

sqlplus is a flaming POS.  some would argue the same is true of its creator.


or wise

Re: [OT]: creating cheat sheets

vu Pham — 2013-04-26T19:03:26

Honestly I do not like vi or vim, but I often use it to the extend that 
when I am on my windows system and need some notes, I open an ssh 
session to my Linux desktop and start typing the notes using vi.

Same thing with sqlplus for Oracle. Many times I have my GUI tool open 
already, I still open a separate sqlplus session to use.

Using the CLI tools is a sign of getting old, I think :)

Re: [OT]: creating cheat sheets

Andrew Gould — 2013-04-26T19:04:54

I've seen those.  I'm making custom cheat sheets for a very focused
 group/class.

Thanks,

Andrew


On Fri, Apr 26, 2013 at 1:52 PM, xDog Walker <thudfoo< at >gmail.com> wrote:

Re: [OT]: creating cheat sheets

xDog Walker — 2013-04-26T18:52:45

http://www.google.com/search?q=python+cheat+sheet&ie=UTF-8&oe=UTF-8

Re: [OT]: creating cheat sheets

Bill Campbell — 2013-04-26T18:20:41

I've always used vim and groff.

Bill

[OT]: creating cheat sheets

Andrew Gould — 2013-04-26T14:16:06

My least favorite tasks at work are those that require visual appeal -
presentation slides, charts, etc.  I now have a need to create a cheat
sheet for basic Python.  (I asked NoStarch Press for a "mug of python", but
they said "no, but here's a coupon code".)

What are the best ways to create cheat sheets?  Are there tools available
that would make it easy?  Would a tool like Scribus be much better than a
word processor?

Thanks,

Andrew

Re: OT: ergonomics and vertical mice

Man-wai Chang — 2013-04-15T18:27:11

Would touch-screen help? Um.. yes and no, I suppose... :)

Re: any perl performance experts awake?

Lonni J Friedman — 2013-04-12T01:02:59

On Thu, Apr 11, 2013 at 4:35 PM, James McDonald
<james< at >jamesmcdonald.id.au> wrote:

yea, basically.  Although it needs to be passed into the subroutine as
\%hash so that its a reference.




--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman                                    netllama< at >gmail.com
LlamaLand                       https://netllama.linux-sxs.org

Re: any perl performance experts awake?

James McDonald — 2013-04-11T23:35:09

Enjoyed this thread...

So passing $hash{key} is expensive because it does a copy of the hash but
passing $hash_ref->{key} stops the expensive copy operation.


On 12 April 2013 06:40, Andrew Gould <andrewlylegould< at >gmail.com> wrote:

Re: any perl performance experts awake?

Andrew Gould — 2013-04-11T20:40:31

Yeah!

Re: any perl performance experts awake?

Lonni J Friedman — 2013-04-11T20:37:34

I figured this out.  It was definitely the hash table lookups that
were the problem.  Or more accurately, the fact that I was passing the
entire hash table into the subroutine thousands of times, which meant
it was being copied thousands of times.  I switched to using a
hashref, and that cut the processing time from hours to a few minutes.

On Thu, Apr 11, 2013 at 12:14 PM, Lonni J Friedman <netllama< at >gmail.com> wrote:

Re: any perl performance experts awake?

Lonni J Friedman — 2013-04-11T19:14:17

On Thu, Apr 11, 2013 at 11:19 AM, Andrew Gould
<andrewlylegould< at >gmail.com> wrote:

The thing is, the data being passed into this slow function
(subroutine) is initially being read from a file, and that portion is
fast.  This seems to suggest that perl is somehow faster at reading &
processing data from disk than in memory, which seems ridiculous to
me.  Surely this would be considered a huge bug that would have been
fixed years ago?

Also, I still suspect that the issue is something related to the hash,
as querying the key from the value in the hash seems to be where the
performance goes downhill. However, everything that I've read suggests
that hashes are the way to go for getting better performance
(especially when compared with an array).

I did find this thread, which seems to suggest that I might benefit
from using a hash reference inside the subroutine, rather than passing
the entire hash:
http://stackoverflow.com/questions/5692349/benefits-of-using-hash-references

Unless someone else has any ideas, I

Re: any perl performance experts awake?

Andrew Gould — 2013-04-11T18:19:20


I can't help with perl specifics, but when I process large files in python,
I don't read the entire input file at once. I read, process and write one
line at a time:

1. Assign input and output files to file handlers using open().
2. Read one line from the input file, process it and write the results to
the output file.  Repeat as necessary.
3. Close the input and output files.

It takes less than an hour to process a large file (input file = 4.5
million rows, 2GB; output file size approximately 890MB) on a system with
2.9GHz processor and 4GB RAM running 32bit WinXP.  (They don't let me use
Linux at work.)

Re: any perl performance experts awake?

Lonni J Friedman — 2013-04-11T16:36:39

Yes, that's how its behaving.  Is there a better way to do this in perl?

Re: any perl performance experts awake?

Andrew Gould — 2013-04-11T16:32:10



The script is holding the input file (>150k rows?) and the hash in memory
while it's reformatting the data and performing sqlinsert().  I was
wondering whether the combination of processing and RAM utilization could
be causing the slowdown.