Re: reiserfs?

[Kevin K]

And, in Red Hat 7.1 (not EL) days, it was a supported journaled filesystem.  
Before EXT3 was supported.

EXT3, once became supported, had the advantage that many of the tools that 
supported EXT2 could work better with it.

On 7/19/17, 3:30 PM, "Konstantin Olchanski" 
 wrote:

On Tue, Jul 18, 2017 at 09:24:44PM -0400, Paul Robert Marino wrote:
> 
> OK well reiserfs is actually EXT2 with a journal slapped on top of it 
just like EXT3 so you can try mounting it as readonly EXT2 though admittedly I 
haven't tried it it should work in theory, but certainly can't hurt if you try 
it in read only mode.
> 


Sheesh. The guy goes to jail and today nobody even remembers what he was 
all about.

reiserfs is not EXT2, not XFS, not flash-fs, not ZFS, not AFS, not ...

It was much better than all of them in exactly 1 way - it was built
to efficiently handle large number of small files.

With reiserfs:

a) a "hello world!" file does not occupy 4k of disk space (tail packing)
b) "rm -rf /" takes 1 second (try to delete some files from ZFS, lucky ot 
be done by tomorrow).
c) "ls -ltR /" does not take 10 days

It was very good while it lasted.

Of course today everybody wants checksums, and dedup, and built-in raid,
and snapshots, and ... and so reiserfs joins the Dodo bird, the 
steam-powered airplane,
and the home made icecream as fond memory of last year's trees were taller,
grass was greener.


https://en.wikipedia.org/wiki/Hans_Reiser

K.O.

   

Re: need SSD RAID controller advice

[Kevin K]

 On May 6, 2015, at 6:31 PM, Vladimir Mosgalin mosga...@vm10124.spb.edu 
 wrote:
 
 Alternative to TRIM-aided GC is Idle Time Garbage Collection (which you
 could see on Plextor), which actively scans data in background, finds
 empty blocks (zeroes) and marks them as free. Well probably more
 complicated than that, but it's the idea. 

A quick search indicates that Idle TIme Garbage Collection is just another term 
for garbage collection.  And I don’t see how it can work as well without TRIM 
as with TRIM, unless massively over provisioned.  There is still the issue 
that, at the file system level, you may now that you just deleted a 1GB file 
that fully fills a whole lot of EBs.  Without trim, the controller can’t know 
that the blocks aren’t in use until the OS attempts to write to those blocks.  
if the controller needs to make space, it will have to copy the stale data that 
it doesn’t know isn’t used anymore.  Now, a continous write to a whole EB’s 
worth of data (still stored in DRAM on the drive), it can see that the whole 
block can be marked as unused, and freed later.  

I’m not sure what the zero blocks you are referring to means.  If you write a 
whole bunch of zeros, is it marked as unused?  Even if contained in a file?  
You really can’t mark obsolete data as zeros since you can’t rewrite until you 
erase first.

Re: need SSD RAID controller advice

[Kevin K]

 On Apr 11, 2015, at 4:39 PM, ToddAndMargo toddandma...@zoho.com wrote:
 
 On 04/11/2015 11:06 AM, Brandon Vincent wrote:
 IR mode
 
 What is IR mode?

That appears to be when the controller is running in RAID mode.  Especially 
with integrated controllers, there can be the option to run the drives in raid 
mode or normal mode.

In the past when I bothered with this in computers I ran at home, the advantage 
of raid mode was you could have, say, 2 hard drives treated as 1 by the BIOS 
and operating system.  So you could boot off of the raid system, and have an OS 
driver take over from it later.  

In normal mode, if you wanted to RAID, you probably needed at least 3 hard 
drives.  A boot drive, and the others raided together using the OS software.  I 
kind of stopped doing this with a combination of OS software being sufficient 
to combine drives, and with drives (even SSDs) getting much larger.

Re: USB point to point computer communications link

[Kevin K]

It isn’t so much the USB.  USB as a design is a master/slave relationship.  So 
you cannot connect 2 normal computers together with an USB cable.  It doesn’t 
matter what you are wanting to do with it.

There have been special USB cables in the past with some smarts in the middle 
so each computer thinks that it is talking to the middle, and it connects the 
2.  Whether they emulated serial cables, or LAN, I don’t recall.  It has been 
years, and I never needed one.

The 2 best suggestions so far has been to put in a second NIC in the desktop, 
and configure the Linux desktop to act as the NAT gateway for the portable.  Or 
just get a NAT router, and have it clone the desktop’s MAC address so it 
doesn’t look any different to the IT department.  Neither of these are a 
solution if you are in an environment where you don’t own the connected 
computers.

 On Mar 27, 2015, at 5:30 PM, Yasha Karant ykar...@csusb.edu wrote:
 
 The university system at which I am tenured has limited practical respect for 
 Faculty but much lipservice to the concept -- that is the reality.  I simply 
 was asking if such a utility existed within EL or Linux in general -- it 
 evidently does not.  UUCP does not easily work over USB although at one time 
 it did work for point-to-point RS-232 connections.  In the future, I will 
 omit the background as to why I post such a request for a utility, merely 
 that I need such a utility if it exists.  In the best of all possible worlds 
 -- not this one -- I would have a grad student, or even a talented undergrad, 
 see if UUCP could be modified.  For now, I am using the modern equivalent of 
 sneaker net.  Sorry to have bothered you.
 
 Yasha Karant
 
 On 03/27/2015 12:37 PM, Konstantin Olchanski wrote:
 
 Yasha, this is getting tiresome - your continuing use of this mailing
 list to obtain free technical support for (imho) bizarre problems or wishes -
 most of them complete with pity pledges please help me, our IT nazi would 
 give me no soup
 (as in Soup Nazi, http://en.wikipedia.org/wiki/The_Soup_Nazi, not the other, 
 bad, nazis).
 
 If your IT problems are real, and if they negatively affect
 your work productivity, why don't you have the boss of your boss
 have a talk with the boss of the boss of the IT departement's boss
 to straighten it all out? If you work at a university, you must
 know how this works.
 
 
 K.O.
 
 
 On Thu, Mar 26, 2015 at 04:37:34PM -0700, Yasha Karant wrote:
 My desktop workstation (currently X86-64 SL 7) has only one 802.3
 physical port.  At my university, the IT gestapo will not allow the
 use of a local 802.3 repeater (switch or hub) but requires a valid
 NIC MAC address and will disconnect any changes.  I have no 802.11
 WNIC on my desktop workstation.  I just have obtained a new HP Zbook
 to run X86-64 Linux to replace my old mobile workstation (laptop)
 that was underprovisioned for 64 bit operation, had a worn out
 keyboard and pointing device, etc. (I regret to state that I am
 experimenting with OpenSUSE 13.2 on that machine for reasons beyond
 the subject matter of this post.)  The IT gestapo will not allow my
 workstation to serve as a HTTP server, etc. -- one cannot use scp,
 sftp, etc., for file transfer over the IT network from a desktop
 workstation (not a designated server).  I could attempt to transfer
 all of the files to the research network that has much less IT
 gestapo control -- but this is as tedious as what I am now doing.
 Hence, a question:
 
 Is there a software application utility that will convert a USB
 network between two machines running standard open systems protocols
 to allow file transfer between the two machines?  I am not referring
 to the methods used with an Android device, but with a regular Linux
 workstation.  A cursory search of such things on the web did not
 provide any insight.  At one time, UUCP would do this over a RS232
 point-to-point link (cable) -- will this approach still work over a
 USB (not RS232) link?  Is there something better than UUCP?
 
 Yasha Karant

Re: USB point to point computer communications link

[Kevin K]

 On Mar 26, 2015, at 6:37 PM, Yasha Karant ykar...@csusb.edu wrote:
 
 My desktop workstation (currently X86-64 SL 7) has only one 802.3 physical 
 port.  At my university, the IT gestapo will not allow the use of a local 
 802.3 repeater (switch or hub) but requires a valid NIC MAC address and will 
 disconnect any changes.  I have no 802.11 WNIC on my desktop workstation.  I 
 just have obtained a new HP Zbook to run X86-64 Linux to replace my old 
 mobile workstation (laptop) that was underprovisioned for 64 bit operation, 
 had a worn out keyboard and pointing device, etc. (I regret to state that I 
 am experimenting with OpenSUSE 13.2 on that machine for reasons beyond the 
 subject matter of this post.)  The IT gestapo will not allow my workstation 
 to serve as a HTTP server, etc. -- one cannot use scp, sftp, etc., for file 
 transfer over the IT network from a desktop workstation (not a designated 
 server).  I could attempt to transfer all of the files to the research 
 network that has much less IT gestapo control -- but this is as tedious as 
 what I am now doing. Hence, a question:
 
 Is there a software application utility that will convert a USB network 
 between two machines running standard open systems protocols to allow file 
 transfer between the two machines?  I am not referring to the methods used 
 with an Android device, but with a regular Linux workstation.  A cursory 
 search of such things on the web did not provide any insight.  At one time, 
 UUCP would do this over a RS232 point-to-point link (cable) -- will this 
 approach still work over a USB (not RS232) link?  Is there something better 
 than UUCP?

Are you wanting to do a one time transfer between the two computers?  Or be 
able to get both on the net at the same time?

For 1 time use, I would suggest a crossover cable.  Configure one to allow the 
SSH daemon to run, and copy files using scp or sftp.

If you want both to connect to the net at the same time, and be able to talk to 
each other, then an inexpensive NAT router should do the trick.  Unless they 
are running special software that can detect that you have multiple computers 
attached to it, there should be no issue.  You still wouldn’t be able to 
connect BACK to your computer from outside if servers aren’t allowed.

Behind NAT, your workstation should be able to be a server to the zbook.