Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
Pandu Poluan writes: On Mar 5, 2012 3:37 AM, Alex Schuster wo...@wonkology.org wrote: Now I have a related question: My new seagate Barracuda Green 2TB ST2000DL003-9VT166 drive has 4096 bytes per sector, but uses something that is called SmartAlign(TM) [*]. Seagate says that there are no performance impacts even when the partitions are misaligned. This would be good, because I completely forgot about this when creating partitions, and I would like to keep it as it is now. Has anyone heard about this? Can I trust Seagate that what they say is correct? [*] www.seagate.com/docs/pdf/de.../mb6101_smartalign_technology_faq.pdf Your URL got munged there, I can't download the pdf. Argh, how did that happen? I just copied from Firefox' address bar. And it was in German anyway. Sorry. But somehow interesting, seems I sometimes don't even notice which language a text is written in. Here is the English version: http://www.seagate.com/docs/pdf/whitepaper/tp615_smartalign_for_af_4k.pdf This link also has some information, and the other one explains what the problem with a 4K sector size is. But beware, this may well be Seagate propaganda. http://consumer.media.seagate.com/2010/06/the-digital-den/advanced-format-drives-with-smartalign/ http://consumer.media.seagate.com/2010/03/the-digital-den/4k-sector-hard-drive-primer/ Wonko
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
Grant writes: The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Neither fdisk nor hdparm seem to get the correct sector size, at least not always. That's what I read somewhere (and not only once), and it's true for my own 2TB drive which I know to have a 4K sector size. I'd say you have to look up the specs on the vendor's web size to be sure. So it doesn't matter where the first partition starts? If you have 4K sectors (and not a Seagate drive with SmartAlign [*]), it does. BTW, here's some benchmarks I just stumbled upon: http://hothardware.com/Articles/WDs-1TB-Caviar-Green-w-Advanced-Format-Windows-XP-Users-Pay-Attention/?page=2 [*] I don't want to sound like I'm advertising for Seagate here, but at least it seems that with SmartAlign the performance impact will be much less, so it might not be worth the trouble of re-partitioning drives that are already being used. Wonko
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 11:04 PM, Alex Schuster wo...@wonkology.org wrote: Grant writes: The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Neither fdisk nor hdparm seem to get the correct sector size, at least not always. That's what I read somewhere (and not only once), and it's true for my own 2TB drive which I know to have a 4K sector size. I'd say you have to look up the specs on the vendor's web size to be sure. So it doesn't matter where the first partition starts? If you have 4K sectors (and not a Seagate drive with SmartAlign [*]), it does. BTW, here's some benchmarks I just stumbled upon: http://hothardware.com/Articles/WDs-1TB-Caviar-Green-w-Advanced-Format-Windows-XP-Users-Pay-Attention/?page=2 [*] I don't want to sound like I'm advertising for Seagate here, but at least it seems that with SmartAlign the performance impact will be much less, so it might not be worth the trouble of re-partitioning drives that are already being used. Wonko The problem with SmartAlign is that..*.* it's magic... once you run out of mana, you can kiss your data goodbye. In other words, I tried to find how it works, but Seagate seems to be mum; and that is ungood. Without knowing how exactly the technology works, how can we be sure that it won't blow up when encountering edge/corner cases? So, albeit nice (in the sense that one does not have to experience the headache in ensuring that partitions are properly aligned), I personally will stay away from magical things. Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mon, 5 Mar 2012 23:33:20 +0700 Pandu Poluan pa...@poluan.info wrote: On Mar 5, 2012 11:04 PM, Alex Schuster wo...@wonkology.org wrote: Grant writes: The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Neither fdisk nor hdparm seem to get the correct sector size, at least not always. That's what I read somewhere (and not only once), and it's true for my own 2TB drive which I know to have a 4K sector size. I'd say you have to look up the specs on the vendor's web size to be sure. So it doesn't matter where the first partition starts? If you have 4K sectors (and not a Seagate drive with SmartAlign [*]), it does. BTW, here's some benchmarks I just stumbled upon: http://hothardware.com/Articles/WDs-1TB-Caviar-Green-w-Advanced-Format-Windows-XP-Users-Pay-Attention/?page=2 [*] I don't want to sound like I'm advertising for Seagate here, but at least it seems that with SmartAlign the performance impact will be much less, so it might not be worth the trouble of re-partitioning drives that are already being used. Wonko The problem with SmartAlign is that..*.* it's magic... once you run out of mana, you can kiss your data goodbye. In other words, I tried to find how it works, but Seagate seems to be mum; and that is ungood. Without knowing how exactly the technology works, how can we be sure that it won't blow up when encountering edge/corner cases? So, albeit nice (in the sense that one does not have to experience the headache in ensuring that partitions are properly aligned), I personally will stay away from magical things. Heretic!! Beleive the magic you muggle!! :-) -- Alan McKinnnon alan.mckin...@gmail.com
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mon, Mar 5, 2012 at 11:00 AM, Alex Schuster wo...@wonkology.org wrote: Grant writes: The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Neither fdisk nor hdparm seem to get the correct sector size, at least not always. That's what I read somewhere (and not only once), and it's true for my own 2TB drive which I know to have a 4K sector size. I'd say you have to look up the specs on the vendor's web size to be sure. So it doesn't matter where the first partition starts? If you have 4K sectors (and not a Seagate drive with SmartAlign [*]), it does. BTW, here's some benchmarks I just stumbled upon: http://hothardware.com/Articles/WDs-1TB-Caviar-Green-w-Advanced-Format-Windows-XP-Users-Pay-Attention/?page=2 [*] I don't want to sound like I'm advertising for Seagate here, but at least it seems that with SmartAlign the performance impact will be much less, so it might not be worth the trouble of re-partitioning drives that are already being used. Wonko Also, it counts with SSDs, where alignment,or lack therof, with the erase block becomes noticeable on write performance. Finding the actual size of an erase block for most SSDs is rather difficult, but 1MB tends to be a reliable guess as a multiple of *that* as well. -- Poison [BLX] Joshua M. Murphy
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Sun, Mar 4, 2012 at 6:06 PM, Pandu Poluan pa...@poluan.info wrote:
On Mar 5, 2012 4:59 AM, Grant emailgr...@gmail.com wrote:
All my drives says this from fdisk:
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
So it doesn't matter where the first partition starts?
Older BIOSes don't understand that hard disks now can have 4KiB sectors, so
some of the advanced format hard disks report a sector size of 512B. But
behind the scenes, the hard disk maps the logical sector to a subsector of
the physical sector.
The only sure fire way to find out if your hard disk uses 4KiB sectors is to
open your computer and eyeball the hard disk. All 4KiB hard disks that I
know of have statements on their surface that tell me so.
Rgds,
I think I must be kind of late to this conversation, but as background
consider hdparm -i coupled with Google for the actual spec:
c2stable ~ # hdparm -i /dev/sdg
/dev/sdg:
Model=WDC WD10EARS-00Z5B1, FwRev=80.00A80, SerialNo=WD-WCAVU0415076
Config={ HardSect NotMFM HdSw15uSec SpinMotCtl Fixed DTR5Mbs FmtGapReq }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=50
BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=off
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=1953525168
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
AdvancedPM=no WriteCache=enabled
Drive conforms to: Unspecified: ATA/ATAPI-1,2,3,4,5,6,7
* signifies the current active mode
c2stable ~ #
With the model number it takes only a minute to determine that this WD
drive is a 4K sector drive. (Which is marked on the drive, as you
state, but I'd have to remove it to find that out.)
Now, in terms of performance, the only requirement (as I understand
it) is that all drive partition be aligned to sector addresses
divisible by 8. (512 * 8 = 4K) The reason 63 gives low performance is
because it's not naturally aligned by 8. With older versions of fdisk
if I started the first partition at 64 then the performance was fine
and only one sector was wasted.
M$, for whatever reason, decided to start at 2048, which is divisible
by 8, reserving the area at the front of the drive for (I think) their
boot loader and other M$-y things. My understanding of why fdisk now
enforces this is simply to be more careful about not overwriting the
M$ boot loaderif it's there. (But I could be very wrong about that!)
Remember, it's possible to make a dual boot system using M$'s loader
instead of grub, and important that fdisk doesn't mangle it when
someone is using that tool.
Just my views,
Mark
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] Got it, I'll just stick with 2048. 2. grub-install reported something like: fd0 hd0 hd1 where hd1 was the USB key. Should I fix this to remove the USB key from grub? I see no problem. The lower number is still the internal hard disk, so grub shouldn't have any trouble booting. Sounds good. 3. Portage complains about duplicate repositories. I think it has to do with the fact that I ran emerge --sync without downloading and extracting an initial snapshot. Try 'rm -rf /usr/portage', download (or copy) portage-latest tarball, and extract it into a re-created /usr/portage I tried that but I get the same message: WARNING: One of more repositories have been ignored due to duplicate profiles/repo_name entires: /, gentoo, /usr/local/portage overrides /usr/portage All profiles/repo_name entries must be unique in order to avoid having duplicates ignored. Set PORTAGE_REPO_DUPLICATE_WARN=0 in /etc/make.conf if you would like to disable this warning. - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] Got it, I'll just stick with 2048. 2. grub-install reported something like: fd0 hd0 hd1 where hd1 was the USB key. Should I fix this to remove the USB key from grub? I see no problem. The lower number is still the internal hard disk, so grub shouldn't have any trouble booting. Sounds good. 3. Portage complains about duplicate repositories. I think it has to do with the fact that I ran emerge --sync without downloading and extracting an initial snapshot. Try 'rm -rf /usr/portage', download (or copy) portage-latest tarball, and extract it into a re-created /usr/portage I tried that but I get the same message: WARNING: One of more repositories have been ignored due to duplicate profiles/repo_name entires: /, gentoo, /usr/local/portage overrides /usr/portage All profiles/repo_name entries must be unique in order to avoid having duplicates ignored. Set PORTAGE_REPO_DUPLICATE_WARN=0 in /etc/make.conf if you would like to disable this warning. - Grant Just figured it out. I had a duplicate tree in /usr/local/portage which I just deleted. I had to re-set my profile with eselect. Please let me know if there's anything else I might have to re-do. - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] snip the rest From what I recall of looking at that toy's specs, it's running on an SSD, so it becomes even more important, performance-wise, to have things aligned properly so any one write doesn't cause two full erase blocks to be cycled. The 1MB alignment is, if I recall, a balance Microsoft struck as the midpoint between multiple hardware vendors to work well on any of them... raid arrays, SSDs, advanced format hard drives with 4k sectors on-disk, etc. Just to confirm, starting at block 2048 is OK? - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
Grant writes: Just to confirm, starting at block 2048 is OK? Yes, if it's divisible by 8, it's okay. That's because 512 * 8 = 4096, so every 8th 512-byte block starts on a 4096 block boundary. Now I have a related question: My new seagate Barracuda Green 2TB ST2000DL003-9VT166 drive has 4096 bytes per sector, but uses something that is called SmartAlign(TM) [*]. Seagate says that there are no performance impacts even when the partitions are misaligned. This would be good, because I completely forgot about this when creating partitions, and I would like to keep it as it is now. Has anyone heard about this? Can I trust Seagate that what they say is correct? [*] www.seagate.com/docs/pdf/de.../mb6101_smartalign_technology_faq.pdf Wonko
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. I just looked up the start block for my other systems and they're all on 63. Is performance impacted on all of these systems since they aren't started on 64? - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Sun, Mar 4, 2012 at 1:09 PM, Grant emailgr...@gmail.com wrote: [snip] 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. I just looked up the start block for my other systems and they're all on 63. Is performance impacted on all of these systems since they aren't started on 64? - Grant The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. HTH, Mark
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. I just looked up the start block for my other systems and they're all on 63. Is performance impacted on all of these systems since they aren't started on 64? - Grant The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes So it doesn't matter where the first partition starts? - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Sun, 4 Mar 2012 13:56:23 -0800 Grant emailgr...@gmail.com wrote: [snip] 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. I just looked up the start block for my other systems and they're all on 63. Is performance impacted on all of these systems since they aren't started on 64? - Grant The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes So it doesn't matter where the first partition starts? Correct. Those drives are all the same style as you've been using for years. If partitions start at 63, that's just an msdos convention. For reasons I've never understood, Windows liked to reserve the first 32k for some purpose or other. -- Alan McKinnnon alan.mckin...@gmail.com
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
[snip] 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. I just looked up the start block for my other systems and they're all on 63. Is performance impacted on all of these systems since they aren't started on 64? - Grant The performance is only impacted if the sector size is something other than 512 bytes. The newer 4K sector size used by some higher density drives requires that you start partitions on a sector boundary or they will perform badly. There isn't an actually performance need to actually start on 2048 but the fdisk-type developer folks are doing that to be more compatible with newer Windows installations. All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes So it doesn't matter where the first partition starts? Correct. Those drives are all the same style as you've been using for years. If partitions start at 63, that's just an msdos convention. For reasons I've never understood, Windows liked to reserve the first 32k for some purpose or other. So fdisk used to enforce a block 63 start point and now it enforces a 2048 start point? fdisk is the one doing this? - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 3:37 AM, Alex Schuster wo...@wonkology.org wrote: Grant writes: Just to confirm, starting at block 2048 is OK? Yes, if it's divisible by 8, it's okay. That's because 512 * 8 = 4096, so every 8th 512-byte block starts on a 4096 block boundary. Now I have a related question: My new seagate Barracuda Green 2TB ST2000DL003-9VT166 drive has 4096 bytes per sector, but uses something that is called SmartAlign(TM) [*]. Seagate says that there are no performance impacts even when the partitions are misaligned. This would be good, because I completely forgot about this when creating partitions, and I would like to keep it as it is now. Has anyone heard about this? Can I trust Seagate that what they say is correct? [*] www.seagate.com/docs/pdf/de.../mb6101_smartalign_technology_faq.pdf Wonko Your URL got munged there, I can't download the pdf. Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 3:15 AM, Grant emailgr...@gmail.com wrote: [snip] HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] snip the rest From what I recall of looking at that toy's specs, it's running on an SSD, so it becomes even more important, performance-wise, to have things aligned properly so any one write doesn't cause two full erase blocks to be cycled. The 1MB alignment is, if I recall, a balance Microsoft struck as the midpoint between multiple hardware vendors to work well on any of them... raid arrays, SSDs, advanced format hard drives with 4k sectors on-disk, etc. Just to confirm, starting at block 2048 is OK? No problem. You'll just be shortchanged of almost 1MiB. Nothing to lose sleep over, IMO. The most important thing is to make sure that *all* partitions begin on sectors divisible by 8. So, if you're going to set up multiple partitions, eyeball their start sectors carefully. Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 4:59 AM, Grant emailgr...@gmail.com wrote: All my drives says this from fdisk: Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes So it doesn't matter where the first partition starts? Older BIOSes don't understand that hard disks now can have 4KiB sectors, so some of the advanced format hard disks report a sector size of 512B. But behind the scenes, the hard disk maps the logical sector to a subsector of the physical sector. The only sure fire way to find out if your hard disk uses 4KiB sectors is to open your computer and eyeball the hard disk. All 4KiB hard disks that I know of have statements on their surface that tell me so. Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 5:10 AM, Alan McKinnon alan.mckin...@gmail.com wrote: Correct. Those drives are all the same style as you've been using for years. If partitions start at 63, that's just an msdos convention. For reasons I've never understood, Windows liked to reserve the first 32k for some purpose or other. Partitions start at sector 63 because traditionally that's the first sector of the second cylinder. If the partition starts at a lower sector, then the metadata of the filesystem might get split between two cylinders, causing a performance impact due to drive head repositioning (older -- like, *really old* drives -- have slow and inaccurate actuators; repositioning heads takes time because after moving the heads, the location needs some fine tuning by reading some calibration data embedded in every cylinder). Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 5, 2012 5:39 AM, Grant emailgr...@gmail.com wrote: So fdisk used to enforce a block 63 start point and now it enforces a 2048 start point? fdisk is the one doing this? - Grant Yes. Like I posted before (and explained in the article I linked), if you turn off the compatibility mode, you can push it down to 63. Not recommended, though. Not only will you lose compatibility with Windows, but also you'll only gain slightly less than 1MiB. And who knows in the future something absofuckinlutely requires the first partition to begin at sector 2048. So, IMO, disabling the DOS compatibility gives one too small a gain that's worth the (possible) headache in the future. Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
I just received the new Dell XPS 13 Ultrabook and I'm trying to install Gentoo but I can't get install-amd64-minimal-20120223.iso to boot via a USB key. Have you tested your boot USB keys on another machine? Gentoo is installed but I can't get my USB-ethernet adapter to bring up an eth0 (or any other) interface. It works if I boot the Kubuntu USB key. I've definitely built the correct driver into the kernel (mcs7380). I'm going through an emerge world right now to bring everything up to date. Is there anything else I might need to do? - Grant I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. 2. grub-install reported something like: fd0 hd0 hd1 where hd1 was the USB key. Should I fix this to remove the USB key from grub? 3. Portage complains about duplicate repositories. I think it has to do with the fact that I ran emerge --sync without downloading and extracting an initial snapshot. Please let me know if you have any idea on these. - Grant
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 4, 2012 12:54 AM, Grant emailgr...@gmail.com wrote: I just received the new Dell XPS 13 Ultrabook and I'm trying to install Gentoo but I can't get install-amd64-minimal-20120223.iso to boot via a USB key. Have you tested your boot USB keys on another machine? Gentoo is installed but I can't get my USB-ethernet adapter to bring up an eth0 (or any other) interface. It works if I boot the Kubuntu USB key. I've definitely built the correct driver into the kernel (mcs7380). I'm going through an emerge world right now to bring everything up to date. Is there anything else I might need to do? - Grant I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] 2. grub-install reported something like: fd0 hd0 hd1 where hd1 was the USB key. Should I fix this to remove the USB key from grub? I see no problem. The lower number is still the internal hard disk, so grub shouldn't have any trouble booting. 3. Portage complains about duplicate repositories. I think it has to do with the fact that I ran emerge --sync without downloading and extracting an initial snapshot. Try 'rm -rf /usr/portage', download (or copy) portage-latest tarball, and extract it into a re-created /usr/portage Please let me know if you have any idea on these. - Grant Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Mar 4, 2012 1:13 AM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 12:54 AM, Grant emailgr...@gmail.com wrote: I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] [1] http://www.ibm.com/developerworks/linux/library/l-4kb-sector-disks/ Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
Oh iya, satu lagi yang perlu dihindari: wifi AP nya HP ProCurve / HP Networking. Nggak stabil. (Tapi kalau switch Layer 2 dan Layer 3 nya, HP ProCurve highly recommended). ((Ini berdasarkan hasil pengalaman saya di kantor yang sekarang.)) Rgds, On Mar 4, 2012 1:15 AM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 1:13 AM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 12:54 AM, Grant emailgr...@gmail.com wrote: I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] [1] http://www.ibm.com/developerworks/linux/library/l-4kb-sector-disks/ Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
Gah. I must be too tired; what I sent earlier was supposed to go another list. Sorry for the mistake, folks. Rgds, On Mar 4, 2012 1:22 AM, Pandu Poluan pa...@poluan.info wrote: Oh iya, satu lagi yang perlu dihindari: wifi AP nya HP ProCurve / HP Networking. Nggak stabil. (Tapi kalau switch Layer 2 dan Layer 3 nya, HP ProCurve highly recommended). ((Ini berdasarkan hasil pengalaman saya di kantor yang sekarang.)) Rgds, On Mar 4, 2012 1:15 AM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 1:13 AM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 12:54 AM, Grant emailgr...@gmail.com wrote: I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] [1] http://www.ibm.com/developerworks/linux/library/l-4kb-sector-disks/ Rgds,
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On Sat, Mar 3, 2012 at 1:13 PM, Pandu Poluan pa...@poluan.info wrote: On Mar 4, 2012 12:54 AM, Grant emailgr...@gmail.com wrote: I just received the new Dell XPS 13 Ultrabook and I'm trying to install Gentoo but I can't get install-amd64-minimal-20120223.iso to boot via a USB key. Have you tested your boot USB keys on another machine? Gentoo is installed but I can't get my USB-ethernet adapter to bring up an eth0 (or any other) interface. It works if I boot the Kubuntu USB key. I've definitely built the correct driver into the kernel (mcs7380). I'm going through an emerge world right now to bring everything up to date. Is there anything else I might need to do? - Grant I enabled some more kernel options under USB Network Adapters and it's working now. The install is about done but there were a few peculiarities: 1. fdisk won't let me specify a start block before 2048 even though I deleted all partitions. That's normal. It's a long story, but Windows Vista and Windows 7 expects the first partition to start at sector 2048. You can force a lower number by toggling DOS compatibility; this should let you start the first partition as low as sector 63. HOWEVER, make sure that all partitions begin at multiples of 8 (e.g., 64, 72, 80, and so on); this will save you a lot of grief if it happens that the hard disk you're using has 4KiB-sectors. [1] snip the rest From what I recall of looking at that toy's specs, it's running on an SSD, so it becomes even more important, performance-wise, to have things aligned properly so any one write doesn't cause two full erase blocks to be cycled. The 1MB alignment is, if I recall, a balance Microsoft struck as the midpoint between multiple hardware vendors to work well on any of them... raid arrays, SSDs, advanced format hard drives with 4k sectors on-disk, etc. -- Poison [BLX] Joshua M. Murphy
[gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
On 03/01/2012 06:12 PM, Grant wrote: I just received the new Dell XPS 13 Ultrabook and I'm trying to install Gentoo but I can't get install-amd64-minimal-20120223.iso to boot via a USB key. Have you tested your boot USB keys on another machine?
Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook
I just received the new Dell XPS 13 Ultrabook and I'm trying to install Gentoo but I can't get install-amd64-minimal-20120223.iso to boot via a USB key. Have you tested your boot USB keys on another machine? Gentoo is installed but I can't get my USB-ethernet adapter to bring up an eth0 (or any other) interface. It works if I boot the Kubuntu USB key. I've definitely built the correct driver into the kernel (mcs7380). I'm going through an emerge world right now to bring everything up to date. Is there anything else I might need to do? - Grant
