From owner-svn-doc-all@FreeBSD.ORG Mon May 12 18:42:03 2014 Return-Path: Delivered-To: svn-doc-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id CDD4DEA2; Mon, 12 May 2014 18:42:03 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B85D02324; Mon, 12 May 2014 18:42:03 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s4CIg3OS091890; Mon, 12 May 2014 18:42:03 GMT (envelope-from dru@svn.freebsd.org) Received: (from dru@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s4CIg3x2091889; Mon, 12 May 2014 18:42:03 GMT (envelope-from dru@svn.freebsd.org) Message-Id: <201405121842.s4CIg3x2091889@svn.freebsd.org> From: Dru Lavigne Date: Mon, 12 May 2014 18:42:03 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44817 - head/en_US.ISO8859-1/books/faq X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 May 2014 18:42:03 -0000 Author: dru Date: Mon May 12 18:42:03 2014 New Revision: 44817 URL: http://svnweb.freebsd.org/changeset/doc/44817 Log: White space fix only. Translators can ignore. Sponsored by: iXsystems Modified: head/en_US.ISO8859-1/books/faq/book.xml Modified: head/en_US.ISO8859-1/books/faq/book.xml ============================================================================== --- head/en_US.ISO8859-1/books/faq/book.xml Mon May 12 15:15:44 2014 (r44816) +++ head/en_US.ISO8859-1/books/faq/book.xml Mon May 12 18:42:03 2014 (r44817) @@ -2895,8 +2895,9 @@ kern.timecounter.hardware: TSC -> i82 xlink:href="&url.books.handbook;/kernelconfig-building.html">build and install your new kernel. - Most kernels (/boot/kernel/kernel) - tend to be around 12 MB to 16 MB. + Most kernels + (/boot/kernel/kernel) tend to be + around 12 MB to 16 MB. @@ -2907,48 +2908,46 @@ kern.timecounter.hardware: TSC -> i82 - There are a number of possible causes for this problem. - They are, in no particular order: + There are a number of possible causes for this + problem. They are, in no particular order: - You are not using the - make buildkernel and - make installkernel - targets, and your source tree is different from the one - used to build the currently running system (e.g., you - are compiling &rel.current;-RELEASE on a - &rel2.current;-RELEASE system). If you are attempting - an upgrade, please read - /usr/src/UPDATING, paying - particular attention to the COMMON ITEMS - section at the end. + You are not using the make + buildkernel and make + installkernel targets, and your source + tree is different from the one used to build the + currently running system (e.g., you are compiling + &rel.current;-RELEASE on a &rel2.current;-RELEASE + system). If you are attempting an upgrade, please + read /usr/src/UPDATING, paying + particular attention to the COMMON + ITEMS section at the end. - You are using the - make buildkernel - and - make installkernel - targets, but you failed to assert the completion of the - make buildworld - target. The - make buildkernel - target relies on files generated by the - make buildworld + You are using the make + buildkernel and make + installkernel targets, but you failed to + assert the completion of the make + buildworld target. The make + buildkernel target relies on files + generated by the make buildworld target to complete its job correctly. - Even if you are trying to build &os;-STABLE, it is possible that - you fetched the source tree at a time when it was either - being modified, or broken for other reasons; only - releases are absolutely guaranteed to be buildable, - although &os;-STABLE - builds fine the majority of the time. If you have not - already done so, try re-fetching the source tree and see - if the problem goes away. Try using a different server - in case the one you are using is having problems. + Even if you are trying to build &os;-STABLE, it is possible + that you fetched the source tree at a time when it was + either being modified, or broken for other reasons; + only releases are absolutely guaranteed to be + buildable, although &os;-STABLE builds fine the + majority of the time. If you have not already done + so, try re-fetching the source tree and see if the + problem goes away. Try using a different server in + case the one you are using is having problems. @@ -2956,8 +2955,8 @@ kern.timecounter.hardware: TSC -> i82 - How can I verify which scheduler is in use on a running - system? + How can I verify which scheduler is in use on a + running system? @@ -2990,53 +2989,57 @@ kern.sched.name: ULE - How can I add my new hard disk to my &os; system? + How can I add my new hard disk to my &os; + system? - See the Adding Disks - section in the &os; Handbook. + See the Adding + Disks section in the &os; Handbook. - How do I move my system over to my huge new disk? + How do I move my system over to my huge new + disk? The best way is to reinstall the OS on the new disk, - then move the user data over. This is highly recommended if - you have been tracking -STABLE for more - than one release, or have updated a release instead of - installing a new one. You can install booteasy on both + then move the user data over. This is highly recommended + if you have been tracking -STABLE for + more than one release, or have updated a release instead + of installing a new one. You can install booteasy on both disks with &man.boot0cfg.8;, and dual boot them until you are happy with the new configuration. Skip the next paragraph to find out how to move the data after doing this. - Alternatively, partition and label the new disk with either - &man.sade.8; or &man.gpart.8;. If the disks are MBR-formatted, - you can also install booteasy on both disks with - &man.boot0cfg.8;, so that you can dual boot to the old or - new system after the copying is done. - - Now you have the new disk set up, and are ready to move - the data. Unfortunately, you cannot just blindly copy the - data. Things like device files (in + Alternatively, partition and label the new disk with + either &man.sade.8; or &man.gpart.8;. If the disks are + MBR-formatted, you can also install booteasy on both disks + with &man.boot0cfg.8;, so that you can dual boot to the + old or new system after the copying is done. + + Now you have the new disk set up, and are ready to + move the data. Unfortunately, you cannot just blindly + copy the data. Things like device files (in /dev), flags, and links tend to screw that up. You need to use tools that understand these - things, which means &man.dump.8;. Although it is suggested - that you move the data in single user mode, it is not - required. + things, which means &man.dump.8;. Although it is + suggested that you move the data in single user mode, it + is not required. You should never use anything but &man.dump.8; and &man.restore.8; to move the root file system. The - &man.tar.1; command may work — then again, it may not. - You should also use &man.dump.8; and &man.restore.8; if you - are moving a single partition to another empty partition. - The sequence of steps to use dump to move - a partitions data to a new partition is: + &man.tar.1; command may work — then again, it may + not. You should also use &man.dump.8; and &man.restore.8; + if you are moving a single partition to another empty + partition. The sequence of steps to use + dump to move a partitions data to a new + partition is: @@ -3059,21 +3062,22 @@ kern.sched.name: ULE For example, if you are going to move root to - /dev/ada1s1a, - with /mnt as - the temporary mount point, it is: + /dev/ada1s1a, with + /mnt as the temporary mount point, it + is: &prompt.root; newfs /dev/ada1s1a &prompt.root; mount /dev/ada1s1a /mnt &prompt.root; cd /mnt &prompt.root; dump 0af - / | restore rf - - Rearranging your partitions with dump - takes a bit more work. To merge a partition like - /var into its parent, create the new - partition large enough for both, move the parent partition - as described above, then move the child partition into the - empty directory that the first move created: + Rearranging your partitions with + dump takes a bit more work. To merge a + partition like /var into its parent, + create the new partition large enough for both, move the + parent partition as described above, then move the child + partition into the empty directory that the first move + created: &prompt.root; newfs /dev/ada1s1a &prompt.root; mount /dev/ada1s1a /mnt @@ -3096,72 +3100,69 @@ kern.sched.name: ULE &prompt.root; cd /mnt &prompt.root; dump 0af - / | restore rf - - You might prefer &man.cpio.1;, &man.pax.1;, &man.tar.1; - to &man.dump.8; for user data. At the time of this writing, - these are known to lose file flag information, so use them - with caution. + You might prefer &man.cpio.1;, &man.pax.1;, + &man.tar.1; to &man.dump.8; for user data. At the time of + this writing, these are known to lose file flag + information, so use them with caution. Which partitions can safely use Soft Updates? I have - heard that Soft Updates on / can cause - problems. What about Journaled Soft Updates? + heard that Soft Updates on / can + cause problems. What about Journaled Soft Updates? - Short answer: you can usually use Soft Updates safely on - all partitions. + Short answer: you can usually use Soft Updates safely + on all partitions. - Long answer: Soft Updates has two - characteristics that may be undesirable on certain - partitions. First, a Soft Updates - partition has a small chance of losing data during a system - crash. (The partition will not be corrupted; the data will - simply be lost.) Second, Soft Updates can cause temporary - space shortages. + Long answer: Soft Updates has two characteristics + that may be undesirable on certain partitions. First, a + Soft Updates partition has a small chance of losing data + during a system crash. (The partition will not be + corrupted; the data will simply be lost.) Second, Soft + Updates can cause temporary space shortages. When using Soft Updates, the kernel can take up to - thirty seconds to write changes to the physical - disk. When a large file is deleted the file still - resides on - disk until the kernel actually performs the deletion. This - can cause a very simple race condition. Suppose you delete - one large file and immediately create another large file. - The first large file is not yet actually removed from the - physical disk, so the disk might not have enough room for - the second large file. You get an error that the partition - does not have enough space, although you know perfectly well - that you just released a large chunk of space! When you try - again mere seconds later, the file creation works as you - expect. This has left more than one user scratching his - head and doubting his sanity, the &os; file system, or - both. + thirty seconds to write changes to the physical disk. + When a large file is deleted the file still resides on + disk until the kernel actually performs the deletion. + This can cause a very simple race condition. Suppose you + delete one large file and immediately create another large + file. The first large file is not yet actually removed + from the physical disk, so the disk might not have enough + room for the second large file. You get an error that the + partition does not have enough space, although you know + perfectly well that you just released a large chunk of + space! When you try again mere seconds later, the file + creation works as you expect. This has left more than one + user scratching his head and doubting his sanity, the &os; + file system, or both. If a system should crash after the kernel accepts a chunk of data for writing to disk, but before that data is - actually written out, data could be lost. This - risk is extremely small, but generally manageable. + actually written out, data could be lost. This risk is + extremely small, but generally manageable. These issues affect all partitions using Soft Updates. So, what does this mean for the root partition? Vital information on the root partition changes very - rarely. If the - system crashed during the thirty-second window after such a - change is made, it is possible that data could be lost. - This risk is negligible for most applications, but you - should be aware that it exists. If your system cannot - tolerate this much risk, do not use Soft Updates on the root - file system! + rarely. If the system crashed during the thirty-second + window after such a change is made, it is possible that + data could be lost. This risk is negligible for most + applications, but you should be aware that it exists. If + your system cannot tolerate this much risk, do not use + Soft Updates on the root file system! / is traditionally one of the smallest partitions. If you put the /tmp directory on / and you have a busy - /tmp, you might see intermittent space - problems. Symlinking /tmp to + /tmp, you might see intermittent + space problems. Symlinking /tmp to /var/tmp will solve this problem. @@ -3188,8 +3189,8 @@ kern.sched.name: ULE UFS CD-ROMs can be mounted directly on &os;. Mounting disk partitions from Digital UNIX and other systems that support UFS may be more complex, - depending on the details of the disk partitioning for - the operating system in question. + depending on the details of the disk partitioning + for the operating system in question. @@ -3208,8 +3209,9 @@ kern.sched.name: ULE FUSE based NTFS support is available as a port - (sysutils/fusefs-ntfs). - For more information see ntfs-3g. + (sysutils/fusefs-ntfs). For more + information see ntfs-3g. @@ -3226,19 +3228,20 @@ kern.sched.name: ULE ZFS - &os; includes a port of - &sun;'s ZFS driver. The current recommendation is to - use it only on &arch.amd64; platforms with sufficient - memory. For more information, see &man.zfs.8;. + &os; includes a port of &sun;'s ZFS driver. The + current recommendation is to use it only on + &arch.amd64; platforms with sufficient memory. For + more information, see &man.zfs.8;. - &os; also supports network file systems such as NFS (see - &man.mount.nfs.8;), NetWare (see &man.mount.nwfs.8;), and - Microsoft-style SMB file systems (see &man.mount.smbfs.8;). - You can find ports based on FUSE (sysutils/fusefs-kmod) for many - other file systems. + &os; also supports network file systems such as NFS + (see &man.mount.nfs.8;), NetWare (see &man.mount.nwfs.8;), + and Microsoft-style SMB file systems (see + &man.mount.smbfs.8;). You can find ports based on FUSE + (sysutils/fusefs-kmod) for many other + file systems. @@ -3251,8 +3254,8 @@ kern.sched.name: ULE The secondary DOS partitions are found after all the primary partitions. For example, if you have an E partition as the - second DOS partition on the second SCSI drive, there will be - a device file for slice 5 in + second DOS partition on the second SCSI drive, there will + be a device file for slice 5 in /dev, so simply mount it: &prompt.root; mount -t msdosfs /dev/da1s5 /dos/e @@ -3266,8 +3269,10 @@ kern.sched.name: ULE Yes. You can use either &man.gbde.8; or &man.geli.8;, - see the Encrypting Disk Partitions - section of the &os; Handbook. + see the Encrypting + Disk Partitions section of the &os; + Handbook. @@ -3282,9 +3287,9 @@ kern.sched.name: ULE your native root &os; partition into a file in the DOS/&windowsnt; partition. Assuming you name that file something like c:\bootsect.bsd - (inspired by c:\bootsect.dos), you can - then edit c:\boot.ini to come - up with something like this: + (inspired by c:\bootsect.dos), you + can then edit c:\boot.ini to come up + with something like this: [boot loader] timeout=30 @@ -3294,20 +3299,22 @@ multi(0)disk(0)rdisk(0)partition(1)\WIND C:\BOOTSECT.BSD="&os;" C:\="DOS" - If &os; is installed on the same disk as the &windowsnt; - boot partition simply copy /boot/boot1 to + If &os; is installed on the same disk as the + &windowsnt; boot partition simply copy + /boot/boot1 to C:\BOOTSECT.BSD. However, if &os; is installed on a different disk /boot/boot1 will not work, /boot/boot0 is needed. /boot/boot0 needs to be installed - using &man.sysinstall.8; by selecting the &os; boot manager - on the screen which asks if you wish to use a boot manager. - This is because /boot/boot0 has the - partition table area filled with NULL characters but - &man.sysinstall.8; copies the partition table before copying - /boot/boot0 to the MBR. + using &man.sysinstall.8; by selecting the &os; boot + manager on the screen which asks if you wish to use a boot + manager. This is because /boot/boot0 + has the partition table area filled with NULL characters + but &man.sysinstall.8; copies the partition table before + copying /boot/boot0 to the + MBR. Do not simply copy @@ -3322,9 +3329,9 @@ C:\="DOS" entry for that OS and then writes the whole 512-bytes of itself back to the MBR so if you just copy /boot/boot0 to - C:\BOOTSECT.BSD then it writes an empty - partition table, with the active flag set on one entry, to - the MBR. + C:\BOOTSECT.BSD then it writes an + empty partition table, with the active flag set on one + entry, to the MBR. @@ -3349,7 +3356,8 @@ C:\="DOS" (the above assumes that your &os; slice is known to &linux; as /dev/hda2; tailor to suit your setup). Then, run lilo as - root and you should be done. + root and you + should be done. If &os; resides on another disk, you need to add loader=/boot/chain.b to the LILO entry. @@ -3361,19 +3369,20 @@ C:\="DOS" label=&os; In some cases you may need to specify the BIOS drive - number to the &os; boot loader to successfully boot off the - second disk. For example, if your &os; SCSI disk is probed - by BIOS as BIOS disk 1, at the &os; boot loader prompt you - need to specify: + number to the &os; boot loader to successfully boot off + the second disk. For example, if your &os; SCSI disk is + probed by BIOS as BIOS disk 1, at the &os; boot loader + prompt you need to specify: Boot: 1:da(0,a)/boot/kernel/kernel - You can configure &man.boot.8; to automatically do this - for you at boot time. + You can configure &man.boot.8; to automatically do + this for you at boot time. - The &linux;+&os; mini-HOWTO - is a good reference for &os; and &linux; interoperability - issues. + The &linux;+&os; + mini-HOWTO is a good reference for &os; and + &linux; interoperability issues. @@ -3397,8 +3406,8 @@ C:\="DOS" root partition on the first disk. If you need to specify which slice number should be used, use something like this (hd0,2,a). By default, if the - slice number is omitted, GRUB searches the first slice which - has a partition. + slice number is omitted, GRUB searches the first slice + which has a partition. @@ -3409,29 +3418,31 @@ C:\="DOS" - Install LILO at the start of your &linux; boot partition - instead of in the Master Boot Record. You can then boot - LILO from BootEasy. + Install LILO at the start of your &linux; boot + partition instead of in the Master Boot Record. You can + then boot LILO from + BootEasy. If you are running &windows; and &linux; this is - recommended anyway, to make it simpler to get &linux; booting - again if you should need to reinstall &windows; (which is a - Jealous Operating System, and will bear no other Operating - Systems in the Master Boot Record). + recommended anyway, to make it simpler to get &linux; + booting again if you should need to reinstall &windows; + (which is a Jealous Operating System, and will bear no + other Operating Systems in the Master Boot Record). How do I change the boot prompt from - ??? to something more meaningful? + ??? to something more + meaningful? You can not do that with the standard boot manager without rewriting it. There are a number of other boot - managers in the sysutils ports category - that provide this functionality. + managers in the sysutils ports + category that provide this functionality. @@ -3441,19 +3452,17 @@ C:\="DOS" - If the drive already has a - file system on it, you can use a command like this: + If the drive already has a file system on it, you can + use a command like this: &prompt.root; mount -t msdosfs /dev/da0s1 /mnt - If the drive will only be used with &os; - systems it is better idea to - stick a BSD file system on it, like UFS or ZFS. - You will get long filename - support, at least a 2X improvement in performance, - and a lot more stability. If the drive will be - used by other operating systems a more portable - choice, such as msdosfs, is better. + If the drive will only be used with &os; systems it is + better idea to stick a BSD file system on it, like UFS or + ZFS. You will get long filename support, at least a 2X + improvement in performance, and a lot more stability. If + the drive will be used by other operating systems a more + portable choice, such as msdosfs, is better. &prompt.root; dd if=/dev/zero of=/dev/da0 count=2 &prompt.root; gpart create -s GPT /dev/da0 @@ -3467,9 +3476,9 @@ C:\="DOS" &prompt.root; mount /dev/da0s1 /mnt - It is a good idea to add a line - to /etc/fstab (see &man.fstab.5;) so - you can just type mount /mnt in the + It is a good idea to add a line to + /etc/fstab (see &man.fstab.5;) so you + can just type mount /mnt in the future: /dev/da0p1 /mnt ufs rw,noauto 0 0 @@ -3484,8 +3493,12 @@ C:\="DOS" You have to tell &man.mount.8; the type of the device - that you want to mount. This is described in the Handbook section on optical media, - specifically the section Using Data CDs. + that you want to mount. This is described in the Handbook + section on optical media, specifically the + section Using + Data CDs. @@ -3498,9 +3511,10 @@ C:\="DOS" This generally means that there is no CD-ROM in the CD-ROM drive, or the drive is not visible on the bus. - Please see the Using Data CDs - section of the Handbook for a detailed discussion of this - issue. + Please see the Using + Data CDs section of the Handbook for a detailed + discussion of this issue. @@ -3514,22 +3528,30 @@ C:\="DOS" Your CD-ROM probably uses the Joliet extension for storing information about files and directories. This is discussed in the Handbook chapter on - creating and using CD-ROMs, - specifically the section on Using Data CD-ROMs. + creating + and using CD-ROMs, specifically the section on + Using + Data CD-ROMs. - I burned a CD under &os; and now I can not read it under - any other operating system. Why? + I burned a CD under &os; and now I can not read it + under any other operating system. Why? You most likely burned a raw file to your CD, rather - than creating an ISO 9660 file system. Take a look at - the Handbook chapter on creating CD-ROMs, - particularly the section on Using Data CDs. + than creating an ISO 9660 file system. Take a look + at the Handbook + chapter on creating CD-ROMs, particularly the + section on Using + Data CDs. @@ -3539,9 +3561,13 @@ C:\="DOS" - This is discussed in the Handbook section on Writing Data to an ISO File System. - For more on working with CD-ROMs, see the Creating CDs Section - in the Storage chapter in the Handbook. + This is discussed in the Handbook section on Writing + Data to an ISO File System. + For more on working with CD-ROMs, see the Creating + CDs Section in the Storage chapter in the + Handbook. @@ -3554,10 +3580,11 @@ C:\="DOS" If you try to mount an audio CD, you will get an error like cd9660: /dev/acd0c: Invalid - argument. This is because - mount only works on file systems. Audio - CDs do not have file systems; they just have data. You need - a program that reads audio CDs, such as the audio/xmcd port. + argument. This is because + mount only works on file systems. + Audio CDs do not have file systems; they just have data. + You need a program that reads audio CDs, such as the + audio/xmcd port. @@ -3568,11 +3595,11 @@ C:\="DOS" - By default, &man.mount.8; will attempt to mount the last - data track (session) of a CD. If you would like to load an - earlier session, you must use the - command line argument. Please see &man.mount.cd9660.8; for - specific examples. + By default, &man.mount.8; will attempt to mount the + last data track (session) of a CD. If you would like to + load an earlier session, you must use the + command line argument. Please see + &man.mount.cd9660.8; for specific examples. @@ -3583,16 +3610,16 @@ C:\="DOS" - As root set the sysctl variable - vfs.usermount to + As root set + the sysctl variable vfs.usermount to 1. &prompt.root; sysctl vfs.usermount=1 To make this persist across reboots, add the line vfs.usermount=1 to - /etc/sysctl.conf so that - it is reset at system boot time. + /etc/sysctl.conf so that it is reset + at system boot time. Users can only mount devices they have read permissions to. To allow users to mount a device @@ -3606,8 +3633,8 @@ C:\="DOS" own /dev/da0 root:operator perm /dev/da0 0666 - All users can now mount devices they could read - onto a directory that they own: + All users can now mount devices they could read onto a + directory that they own: &prompt.user; mkdir ~/my-mount-point &prompt.user; mount -t msdosfs /dev/da0 ~/my-mount-point @@ -3616,14 +3643,15 @@ C:\="DOS" &prompt.user; umount ~/my-mount-point - Enabling vfs.usermount, however, has - negative security implications. A better way to access - &ms-dos; formatted media is to use the emulators/mtools package in the - Ports Collection. + Enabling vfs.usermount, however, + has negative security implications. A better way to + access &ms-dos; formatted media is to use the + emulators/mtools package in the Ports + Collection. - The device name used in the previous examples must be - changed according to your configuration. + The device name used in the previous examples must + be changed according to your configuration. @@ -3637,19 +3665,19 @@ C:\="DOS" You need to understand what du and - df really do. du goes - through the directory tree, measures how large each file is, - and presents the totals. df just asks - the file system how much space it has left. They seem to be - the same thing, but a file without a directory entry will - affect df but not + df really do. du + goes through the directory tree, measures how large each + file is, and presents the totals. df + just asks the file system how much space it has left. + They seem to be the same thing, but a file without a + directory entry will affect df but not du. - When a program is using a file, and you delete the file, - the file is not really removed from the file system until - the program stops using it. The file is immediately deleted - from the directory listing, however. You can see this - easily enough with a program such as + When a program is using a file, and you delete the + file, the file is not really removed from the file system + until the program stops using it. The file is immediately + deleted from the directory listing, however. You can see + this easily enough with a program such as more. Assume you have a file large enough that its presence affects the output of du and df. (Since @@ -3657,21 +3685,22 @@ C:\="DOS" very large file!) If you delete this file while using more on it, more does not immediately choke and - complain that it cannot view the file. The entry is simply - removed from the directory so no other program or user can - access it. du shows that it is gone - — it has walked the directory tree and the file is not - listed. df shows that it is still there, - as the file system knows that more is - still using that space. Once you end the - more session, du and - df will agree. + complain that it cannot view the file. The entry is + simply removed from the directory so no other program or + user can access it. du shows that it + is gone — it has walked the directory tree and the + file is not listed. df shows that it + is still there, as the file system knows that + more is still using that space. Once + you end the more session, + du and df will + agree. This situation is common on web servers. Many people - set up a &os; web server and forget to rotate the log files. - The access log fills up /var. The new - administrator deletes the file, but the system still - complains that the partition is full. Stopping and + set up a &os; web server and forget to rotate the log + files. The access log fills up /var. + The new administrator deletes the file, but the system + still complains that the partition is full. Stopping and restarting the web server program would free the file, allowing the system to release the disk space. To prevent this from happening, set up &man.newsyslog.8;. @@ -3688,8 +3717,11 @@ C:\="DOS" - In the Configuration and Tuning - section of the Handbook, you will find a section + In the Configuration + and Tuning section of the Handbook, you will find + a section describing how to do this. @@ -3705,32 +3737,34 @@ C:\="DOS" bytes each, whereas &os; calculates them as 1,073,741,824 bytes each. This explains why, for example, &os;'s boot messages will report a disk that - supposedly has 80 GB as holding 76,319 MB. + supposedly has 80 GB as holding + 76,319 MB. - Also note that &os; will (by default) reserve 8% of the disk - space. + Also note that &os; will (by default) reserve 8% of the + disk space. - How is it possible for a partition to be more than 100% - full? + How is it possible for a partition to be more than + 100% full? A portion of each UFS partition (8%, by default) is reserved for use by the operating system and the - root user. &man.df.1; does not count - that space when calculating the Capacity - column, so it can exceed 100%. Also, you will notice that - the Blocks column is always greater than - the sum of the Used and - Avail columns, usually by a factor of - 8%. + root user. + &man.df.1; does not count that space when calculating the + Capacity column, so it can exceed 100%. + Also, you will notice that the Blocks + column is always greater than the sum of the + Used and Avail + columns, usually by a factor of 8%. - For more details, look up - in &man.tunefs.8;. + For more details, look up in + &man.tunefs.8;. @@ -3744,10 +3778,9 @@ C:\="DOS" &os; does a short memory test early in the boot process. This test usually only takes several seconds, however if the system has many 10s or 100s of gigabytes - of memory it can take up to a few minutes. This test - can be disabled by setting - hw.memtest.tests to - 0 in + of memory it can take up to a few minutes. This test can + be disabled by setting hw.memtest.tests + to 0 in /boot/loader.conf. For more details, see &man.loader.conf.5;. @@ -3780,16 +3813,16 @@ C:\="DOS" The ZIL ((ZFS intent log) is a write log used to implement posix write commitment semantics across crashes. Normally writes - are bundled up into transaction groups - and written to disk when filled (Transaction Group + are bundled up into transaction groups and written to + disk when filled (Transaction Group Commit). However syscalls like &man.fsync.2; require a commitment that the data is written to stable - storage before returning. - The ZIL is needed for writes that have been acknowledged - as written but which are not yet on disk as part of a - transaction. The transaction groups are timestamped. - In the event of a crash the last valid timestamp is - found and missing data is merged in from the ZIL. + storage before returning. The ZIL is needed for writes + that have been acknowledged as written but which are not + yet on disk as part of a transaction. The transaction + groups are timestamped. In the event of a crash the + last valid timestamp is found and missing data is merged + in from the ZIL. @@ -3816,17 +3849,16 @@ C:\="DOS" The L2ARC is a read cache stored on a fast device such as an SSD. - This cache is not persistent across - reboots. Note that RAM is used as the first layer - of cache and the L2ARC is only needed if there is - insufficient RAM. + This cache is not persistent across reboots. Note that + RAM is used as the first layer of cache and the L2ARC is + only needed if there is insufficient RAM. L2ARC needs space in the ARC to index it. So, perversely, a working set that fits perfectly in the ARC will not fit perfectly any more if a L2ARC is used because part of the ARC is holding the L2ARC index, - pushing part of the working set into the - L2ARC which is slower than RAM. + pushing part of the working set into the L2ARC which is + slower than RAM. @@ -3838,20 +3870,20 @@ C:\="DOS" Generally speaking, no. - Deduplication takes up a significant amount - of RAM and may slow down read and write - disk access times. Unless one is storing data that is - very heavily duplicated (such as virtual machine images, - or user backups) it is possible that deduplication will - do more harm than good. Another consideration is the - inability to revert deduplication status. If data is - written when deduplication is enabled, disabling dedup - will not cause those blocks which were deduplicated to - be replicated until they are next modified. + Deduplication takes up a significant amount of RAM + and may slow down read and write disk access times. + Unless one is storing data that is very heavily + duplicated (such as virtual machine images, or user + backups) it is possible that deduplication will do more + harm than good. Another consideration is the inability + to revert deduplication status. If data is written when + deduplication is enabled, disabling dedup will not cause + those blocks which were deduplicated to be replicated + until they are next modified. Deduplication can also lead to some unexpected - situations. In particular deleting files may become much - slower. + situations. In particular deleting files may become + much slower. @@ -3863,20 +3895,20 @@ C:\="DOS" This could happen because the pool is 100% full. - ZFS requires space on the disk to write - transaction metadata. To restore the pool *** DIFF OUTPUT TRUNCATED AT 1000 LINES ***