I just used a Live CD for the first time today, in part to show what CentOS can do for a co-worker who is looking at using it at work and home, but I got the strangest result.
We booted the CD and let the centos user log in. It took a really long time to load the desktop and there were no panels, so the only things we could do were browse the computer, CD, home, file system, keyboard (sort of) and pretty much nothing else. <alt><f2> and <alt><f1> did nothing, either - no menu, no input windows - nada.
Is that normal? If not, what did I/we overlook? I was expecting a lot more, and from looking around the wiki, there should have been, but I couldn't find a good reference for what the Live CD is supposed to be able to do or let a user do.
Thanks.
mhr
MHR wrote:
I just used a Live CD for the first time today, in part to show what CentOS can do for a co-worker who is looking at using it at work and home, but I got the strangest result.
We booted the CD and let the centos user log in. It took a really long time to load the desktop and there were no panels, so the only things we could do were browse the computer, CD, home, file system, keyboard (sort of) and pretty much nothing else. <alt><f2> and <alt><f1> did nothing, either - no menu, no input windows - nada.
Is that normal? If not, what did I/we overlook? I was expecting a lot more, and from looking around the wiki, there should have been, but I couldn't find a good reference for what the Live CD is supposed to be able to do or let a user do.
Both live CDs (CentOS-4 and CentOS-5) boot to fully usable desktops.
It sounds like there are hardware issues with the machine involved and the livecd booted.
On Wed, Jun 4, 2008 at 3:24 AM, Johnny Hughes johnny@centos.org wrote:
Both live CDs (CentOS-4 and CentOS-5) boot to fully usable desktops.
It sounds like there are hardware issues with the machine involved and the livecd booted.
Sounds likely - I'll check what I can....
mhr
on 6-3-2008 11:51 AM MHR spake the following:
I just used a Live CD for the first time today, in part to show what CentOS can do for a co-worker who is looking at using it at work and home, but I got the strangest result.
We booted the CD and let the centos user log in. It took a really long time to load the desktop and there were no panels, so the only things we could do were browse the computer, CD, home, file system, keyboard (sort of) and pretty much nothing else. <alt><f2> and <alt><f1> did nothing, either - no menu, no input windows - nada.
Is that normal? If not, what did I/we overlook? I was expecting a lot more, and from looking around the wiki, there should have been, but I couldn't find a good reference for what the Live CD is supposed to be able to do or let a user do.
Thanks.
mhr
Corrupted CD maybe?
On Wed, Jun 4, 2008 at 8:16 AM, Scott Silva ssilva@sgvwater.com wrote:
Corrupted CD maybe?
Could be. I burned it at 40x (it's a 48x TDK CD) using K3B with write verification, so it passed the md5sum after the write completed. I suppose it could be an incompatibility between my burner (a Pioneer 18xXxXx DVD burner) and the reader (a TEAC CD-540E).
I noticed that the target system, which normally runs (well, actually, walks is more like it) Ubuntu 8, only has 256MB of memory - could that be part of it?
The other oddball thing was that, after we had booted the LiveCD and given up on it, we had to reboot the Ubuntu in repair mode to get it back up (!!!).
I haven't tried it anywhere else just yet....
mhr
on 6-4-2008 12:24 PM MHR spake the following:
On Wed, Jun 4, 2008 at 8:16 AM, Scott Silva ssilva-m4n3GYAQT2lWk0Htik3J/w@public.gmane.org wrote:
Corrupted CD maybe?
Could be. I burned it at 40x (it's a 48x TDK CD) using K3B with write verification, so it passed the md5sum after the write completed. I suppose it could be an incompatibility between my burner (a Pioneer 18xXxXx DVD burner) and the reader (a TEAC CD-540E).
I noticed that the target system, which normally runs (well, actually, walks is more like it) Ubuntu 8, only has 256MB of memory - could that be part of it?
The other oddball thing was that, after we had booted the LiveCD and given up on it, we had to reboot the Ubuntu in repair mode to get it back up (!!!).
I haven't tried it anywhere else just yet....
mhr
I usually burn critical CD's at lower speeds. It seems that they have a more reliable image when the laser gets to spend a little more time on the tracks.
On Wed, Jun 4, 2008 at 12:50 PM, Scott Silva ssilva@sgvwater.com wrote:
I usually burn critical CD's at lower speeds. It seems that they have a more reliable image when the laser gets to spend a little more time on the tracks.
I'll have to check the file at home again - I just checked the CD here and its md5sum doesn't match the one on the download site's md5sum.txt file.
)(*@#&$)%(*&@#$(*@&$#(&@
Back to the basics....
Thanks.
mhr
On Wed, 2008-06-04 at 13:13 -0700, MHR wrote:
On Wed, Jun 4, 2008 at 12:50 PM, Scott Silva ssilva@sgvwater.com wrote:
I usually burn critical CD's at lower speeds. It seems that they have a more reliable image when the laser gets to spend a little more time on the tracks.
I'll have to check the file at home again - I just checked the CD here and its md5sum doesn't match the one on the download site's md5sum.txt file.
)(*@#&$)%(*&@#$(*@&$#(&@
Back to the basics....
Pad the image before you burn it. Per suggestions from Johnny when I got burned by this some time back, 300K is sufficient.
FYI: being insatiably curious, after that fix was applied, I grabbed a handful of my old CD drives (all different brands and ages and speeds) and used a recent one as the master burner. That is, all test media were burned on the same device.
Some of the readers (1 IIRC) read successfully w/o padding. All others required some - amount varied. All tests conducted in the same machine.
If you use cdrecord, note that the pad parameter is deprecated and replaced with padsize, which works quite well.
The clue in all this is that someone mentioned that some drives have trouble reading the end of the track. This was confirmed by my tests.
Thanks.
mhr
<snip sig stuff>
HTH
MHR wrote:
I just used a Live CD for the first time today, in part to show what CentOS can do for a co-worker who is looking at using it at work and home, but I got the strangest result.
We booted the CD and let the centos user log in. It took a really long time to load the desktop and there were no panels, so the only things we could do were browse the computer, CD, home, file system, keyboard (sort of) and pretty much nothing else. <alt><f2> and <alt><f1> did nothing, either - no menu, no input windows - nada.
Is that normal? If not, what did I/we overlook? I was expecting a lot more, and from looking around the wiki, there should have been, but I couldn't find a good reference for what the Live CD is supposed to be able to do or let a user do.
Incompatible burn for that reader? (cd-r, cd+r, cd-rw, cd+rw ...)
Or maybe it is just the skew of the burn is outside of that readers acceptable range.
-Ross
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On Tue, 2008-06-03 at 11:51 -0700, MHR wrote:
I just used a Live CD for the first time today, in part to show what CentOS can do for a co-worker who is looking at using it at work and home, but I got the strangest result.
<snip>
Mark: First, I believe that you should always TYS (Test Your Stuff). You were very lucky the demo was for a colleague and not for your Manager or his/her boss! Test what you do, as much as is possible, so others do not catch your mistakes! TYS... There are reasons for V&V (Verification and Validation), Design Walk Through, etc. The earlier mistakes are found, the easier it is to fix them.
I have a Live CD for an earlier version of CentOS and we have one old box (Firewall/Router backup) it will not run on. I believe that's because of a video problem.
The Live CD's have a number of uses, which include: (a) Being able to Rescue a box that has bad problems. They usually have many utilities on them (b) That one can see if the regular Installation will fly on the HW, before actually trying to install. (c) You can take a Live CD with you to a store, if you are contemplating buying a box, and see if Linux will run on it (d) I plan to take a Knoppix Live CD with me, when I travel, so if I need to use a Public box, I can boot Knoppix, do whatever I need to do, and not leave a footprint.
The Knoppix Live CD has been recommended here on this ML and is very popular. In your case, the CentOS Live CD was a better choice, since your colleague is interested in using CentOS (a great idea).
Seems like you have a TEAC burner. Someone here on this list, last year, told me that he does not like them. I personally will not buy any more TEAC drives, because recently, I learned they did not have Diagnostics for my CD-RW drive. It went into the trash. Drives that we have had good luck with include: Samsung, SONY & LG. Other's probably work just as well. We have other TEAC drives, but they are the last TEAC drives we will purchase.
The CD-R media I usually buy are Imation or Verbatim. Never had a problem. There are probably other brands equally good.
When I burned the Knoppix Live CDs, K3B burned them at a high speed as I recall, but, as has been suggested in prior responses, throttling back on the speed probably greatly increases the chance of getting a good burn. K3B checks the MD5 sum, as I recall, when it begins the process. HTH, Lanny
On Friday 06 June 2008 13:20:02 Lanny Marcus wrote:
Drives that we have had good luck with include: Samsung, SONY & LG. Other's probably work just as well. We have other TEAC drives, but they are the last TEAC drives we will purchase.
I would add Lite-On to the list. I've had several, including a stand-alone DVD recorder, and been highly satisfied with them.
The CD-R media I usually buy are Imation or Verbatim. Never had a problem. There are probably other brands equally good.
Memorex to a range that they call "Memorex Professional" - about 10% more expensive than their basic range. I've found that I can let K3B run full-tilt on them, doing a fast burn and getting good results. Prior to finding them I always had to throttle back.
When I burned the Knoppix Live CDs, K3B burned them at a high speed as I recall, but, as has been suggested in prior responses, throttling back on the speed probably greatly increases the chance of getting a good burn. K3B checks the MD5 sum, as I recall, when it begins the process.
The only problem with K3B is that on some installations it ejects the disk after the burn, then fails to pull it in again for the verify, so that you have to manually run md5sum or sha1sum to check it.
Anne
On Fri, Jun 6, 2008 at 5:38 AM, Anne Wilson cannewilson@googlemail.com wrote:
On Friday 06 June 2008 13:20:02 Lanny Marcus wrote:
Drives that we have had good luck with include: Samsung, SONY & LG. Other's probably work just as well. We have other TEAC drives, but they are the last TEAC drives we will purchase.
I would add Lite-On to the list. I've had several, including a stand-alone DVD recorder, and been highly satisfied with them.
Actually, I said (and it's true) that the burner was a Pioneer DVD +/-RW DL 18x, with which I have so far had pretty good luck. It turns out that the image was bad, which I missed....
The reader is a Teac CD-540E CD drive, but the original iso image that came down was no good.
The CD-R media I usually buy are Imation or Verbatim. Never had a problem. There are probably other brands equally good.
Memorex to a range that they call "Memorex Professional" - about 10% more expensive than their basic range. I've found that I can let K3B run full-tilt on them, doing a fast burn and getting good results. Prior to finding them I always had to throttle back.
I'm somewhat fond of TDK, but their newer, high-speed (16x+) DVDs have been pretty iffy for me - the old ones (4x), and their CDs, are rock solid, and the newer Memorex and Sony discs have been fairly reliable for me (but Costco only carries TDK - foo).
Thanks.
mhr
The CD-R media I usually buy are Imation or Verbatim. Never had a problem. There are probably other brands equally good.
Memorex to a range that they call "Memorex Professional" - about 10% more expensive than their basic range. I've found that I can let K3B run full-tilt on them, doing a fast burn and getting good results. Prior to finding them I always had to throttle back.
I'm somewhat fond of TDK, but their newer, high-speed (16x+) DVDs have been pretty iffy for me - the old ones (4x), and their CDs, are rock solid, and the newer Memorex and Sony discs have been fairly reliable for me (but Costco only carries TDK - foo).
TDK, Memorex, Imation, Verbatim, I don't believe ANY of those actually make their own disks. My TDK's have a media code of "CMC MAG. AM3", which is, I believe, CMC Magnetics, a middle grade disk, OK but not great. Note that there's some OTHER CMC disks which are apparently pure garbage. These "AM3" code disks can be found with Ricoh, , Memorex, Staples, and god knows how many other brands on the label. And, a different label of TDK disk might be from a different pressing plant.
that said, I've burned 100s and 100s of the Costco 16X TDK "CMC MAG. AM3" DVDs with very very few problems. I've had several DVD burners, currently mostly using a Pioneer DVR-112D (16x DL), previously I had a "Sony" that was really a rebranded LiteOn, but after a couple years of heavy use, it started getting too many burn errors, so I retired it.
I have noted that DVD video is best burned at 8X, which is a CLV mode (16X is a CAV mode), as the error rate goes up considerably on the last 20% or so of the disk when it actually hits the 16X speeds, too many of my 16X burned home videos have glitches near the end.. "16X" CAV burns actually average about 11X, so its really not that much slower to burn 8X overall. I've also found my computers are much less fussier about the disks than regular DVD players.
Supposedly, disks by Taiyo Yuden are the best, these are often sold as "That's DVD"
These guys have extensive reasonably technical evaluations of burners and media, http://www.cdrinfo.com/Sections/Reviews/Home.aspx?CategoryId=1 they actually do error rate plots on every disk, and try different drives with many different media types. Reading too much of this can be depressing, when you realize just how marginal all this stuff actually is :)
On Friday 06 June 2008 20:12:57 John R Pierce wrote:
TDK, Memorex, Imation, Verbatim, I don't believe ANY of those actually make their own disks.
I understand that there are only two or three manufacturers and that the 'brands' may well buy from more than one of them. I did quite a lot of reading about this at one time, and it seems that the output of some factories is less reliable than the output of other factories. It all comes down to qa, and I suspect that's what the extra 10% pays for in Memorex's Professional range.
Anne
On Fri, Jun 6, 2008 at 12:12 PM, John R Pierce pierce@hogranch.com wrote:
TDK, Memorex, Imation, Verbatim, I don't believe ANY of those actually make their own disks. My TDK's have a media code of "CMC MAG. AM3", which is, I believe, CMC Magnetics, a middle grade disk, OK but not great. Note that there's some OTHER CMC disks which are apparently pure garbage. These "AM3" code disks can be found with Ricoh, , Memorex, Staples, and god knows how many other brands on the label. And, a different label of TDK disk might be from a different pressing plant.
Hmm - sounds like we need a corollary to Nero's InfoTool for Linux to get at that....
that said, I've burned 100s and 100s of the Costco 16X TDK "CMC MAG. AM3" DVDs with very very few problems. I've had several DVD burners, currently mostly using a Pioneer DVR-112D (16x DL), previously I had a "Sony" that was really a rebranded LiteOn, but after a couple years of heavy use, it started getting too many burn errors, so I retired it.
I used to have a couple of Emprex burners - I forget who _really_ made them - that were quite nice despite being a junk brand from Fry's. The 4x burner was slow but reliable, and the 16x burner was fast and could burn DVDs that read in DVD players and most other PC drives if the discs were burned at 12x (not 16x). Unfortuantely, both of them are now history, having died long before my time.
I had a Hammer 18x drive that was really a Panasonic, but it didn't have all the speeds, and it died long before my Emprex 16x, even though it was about a year newer.
I now have a Pioneer 18x burner that's pretty decent (although I haven't gotten it past 12x for DVDs and 40x for CDs), and a Samsung (i.e., Toshiba-Samsung) 20x drive that, so far, hasn't burned one DVD above 2.4x, or one that was any good in any drive, including itself. (I need to get some tech support for that one - blecch!)
I have noted that DVD video is best burned at 8X, which is a CLV mode (16X is a CAV mode), as the error rate goes up considerably on the last 20% or so of the disk when it actually hits the 16X speeds, too many of my 16X burned home videos have glitches near the end.. "16X" CAV burns actually average about 11X, so its really not that much slower to burn 8X overall. I've also found my computers are much less fussier about the disks than regular DVD players.
I agree 100%.
Supposedly, disks by Taiyo Yuden are the best, these are often sold as "That's DVD"
Never heard of them - where do you find these?
HTH
mhr
PS: w.r.t. the original topic here, I pulled down a new LiveCD iso image, and this one passed the md5sum. I used K3B here at work to burn two of them. Both completed the burn but the verification failed, so I mounted the iso file as a loop drive and compared all the files - fine. Booted from the CD - fine. Looks okay to me.
On Fri, 2008-06-06 at 12:50 -0700, MHR wrote:
On Fri, Jun 6, 2008 at 12:12 PM, John R Pierce pierce@hogranch.com wrote:
TDK, Memorex, Imation, Verbatim, I don't believe ANY of those actually make their own disks. My TDK's have a media code of "CMC MAG. AM3", which is, I believe, CMC Magnetics,<snip>
Hmm - sounds like we need a corollary to Nero's InfoTool for Linux to get at that....
Nope. Cdrtools/cdrecord can read all that stuff and tell you what you want to know. CLI though.
that said, I've burned 100s and 100s of the Costco 16X TDK "CMC MAG. AM3" DVDs with very very few problems. I've had several DVD burners, currently mostly using a Pioneer DVR-112D (16x DL), previously I had a "Sony" that was really a rebranded LiteOn, but after a couple years of heavy use, it started getting too many burn errors, so I retired it.
I've always bought the store brands except for once (wanted "High Speed" compatible CD). I burn 'em at full speed, test 'em carefully and can any bad ones - very few to-date. The savings are great enough that if I have to trash one or two, NP. Of course, if you've something more important to do, it does cost a Little of your time and may not be worth the savings.
<snip>
-
Anne Wilson -
Armando M. Baratti -
John R Pierce -
Johnny Hughes -
Lanny Marcus -
MHR -
Ross S. W. Walker -
Scott Silva -
William L. Maltby