Philip Durbin's questions

I noticed that https://github.com/apache/ant says "mirrored from git://git.apache.org/ant.git" (with a link) and I'd like to do the same.

https://exyr.org/2011/git-mirrors/ seems like a good write up of the general technique (basically a cron job), but I'm getting some odd errors and I don't see "mirrored from" at https://github.com/pdurbin/openscholar (the destinatation). I'd like the source for the mirror to be https://github.com/openscholar/openscholar

Here is the (trimmed) output I'm seeing:

murphy:~ pdurbin$ cd /tmp
murphy:tmp pdurbin$ git clone --mirror https://github.com/openscholar/openscholar.git
Cloning into bare repository 'openscholar.git'...
remote: Counting objects: 167069, done.
remote: Compressing objects: 100% (51806/51806), done.
remote: Total 167069 (delta 112936), reused 166304 (delta 112255)
Receiving objects: 100% (167069/167069), 82.77 MiB | 650 KiB/s, done.
Resolving deltas: 100% (112936/112936), done.
murphy:tmp pdurbin$ cd openscholar.git
murphy:openscholar.git pdurbin$ git remote add github [email protected]:pdurbin/openscholar.git
murphy:openscholar.git pdurbin$ git fetch -q && git push -q --mirror github
remote: error: hook declined to update refs/pull/1001/head
remote: error: hook declined to update refs/pull/1001/merge
(snip)
remote: error: hook declined to update refs/pull/957/head
remote: error: hook declined to update refs/pull/957/merge
To [email protected]:pdurbin/openscholar.git
 * [new branch]      1017 -> 1017
(snip)
 * [new branch]      origin/SCHOLAR-3.x-make-1072 -> origin/SCHOLAR-3.x-make-1072
 * [new tag]         SCHOLAR-2-0-BETA1 -> SCHOLAR-2-0-BETA1
(snip)
 * [new tag]         SCHOLAR-3.1.6 -> SCHOLAR-3.1.6
 ! [remote rejected] refs/pull/1001/head -> refs/pull/1001/head (hook declined)
 ! [remote rejected] refs/pull/1001/merge -> refs/pull/1001/merge (hook declined)
(snip)
 ! [remote rejected] refs/pull/957/head -> refs/pull/957/head (hook declined)
 ! [remote rejected] refs/pull/957/merge -> refs/pull/957/merge (hook declined)
error: failed to push some refs to '[email protected]:pdurbin/openscholar.git'
murphy:openscholar.git pdurbin$ 

I need to migrate a number of virtual machines from VMware ESX to CentOS 6 KVM hypervisors. Ultimately, I wrote an RPM spec file that solved my problem at https://github.com/fasrc/virtio-win/blob/master/virtio-win.spec but I'm not sure if there's another RPM in base CentOS or EPEL (something standard) I should be using instead.

Originally, I was getting this "No root device found in this operating system image" error when attemting to migrate a Window 2008 VM. . .

[root@kvm01b ~]# virt-v2v -ic 'esx://my-vmware-hypervisor.example.com/' \
-os transferimages --network default my-vm
virt-v2v: No root device found in this operating system image.

. . . but I solved this with a simply yum install libguestfs-winsupport since the docs say:

If you attempt to convert a virtual machine using NTFS without the libguestfs-winsupport package installed, the conversion will fail.

Next I got an error about missing drivers for Windows 2008. . .

[root@kvm01b ~]# virt-v2v -ic 'esx://my-vmware-hypervisor.example.com/' \
-os transferimages --network default my-vm
my-vm_my-vm: 100% [====================================]D
virt-v2v: Installation failed because the following files referenced in
the configuration file are required, but missing:
/usr/share/virtio-win/drivers/amd64/Win2008

. . . and I resolved this by grabbing an iso from Fedora at http://alt.fedoraproject.org/pub/alt/virtio-win/latest/ as recommended by http://www.linux-kvm.org/page/WindowsGuestDrivers/Download_Drivers and building an RPM from it with this spec file: https://github.com/fasrc/virtio-win/blob/master/virtio-win.spec

Now, virt-v2v exits without error:

[root@kvm01b ~]# virt-v2v -ic 'esx://my-vmware-hypervisor.example.com/' \
-os transferimages --network default my-vm
my-vm_my-vm: 100% [====================================]D
virt-v2v: my-vm configured with virtio drivers.
[root@kvm01b ~]# 

Now, my question is, rather that the virtio-win RPM from the spec file I wrote, is there some other more standard RPM in base CentOS or EPEL that will resolve the error above?

Here's a bit more detail about my setup:

[root@kvm01b ~]# cat /etc/redhat-release 
CentOS release 6.2 (Final)
[root@kvm01b ~]# rpm -q virt-v2v
virt-v2v-0.8.3-5.el6.x86_64

See also Bug 605334 – VirtIO driver for windows does not show specific OS: Windows 7, Windows 2003

In January 2012 Randal Schwartz gave a talk called Introduction to Git that I very much enjoyed, but I was left confused about his admonition not to use git to track individual files with unrelated or separate history.

Page 4 of his slides contain the following bullet points. . .

But not for...

• Tracking file permissions and ownership
• Tracking individual files with separate history
• Making things painful

. . . and here is what he says, around 4 minutes in:

It is not optimized for any kind of metadata about the files. It does not, it does not, track file permissions or file ownership. That is not its job. It's managing source files, and sources don't have owners, sources don't have permissions. Sources are used in recipes to build the real thing that you are going to deploy. So git does not have technology about that. People have tried to build structures on top of it to do that, with some degree of success, but really let's look at basically what git is meant for and not what people are building on top of it.

It's also not meant for tracking individual files with unrelated or separate history. For example, you may think, "Oh, I really like this. I want to track all my et cetera with it. But et cetera is really a bunch of separate, unrelated files. You wouldn't be doing branching and merging. . . add this change to that change and eventually want to back out both of them at the same time. It doesn't really work that way. So it's not good for individual files.

I still use RCS to track individual files in my /etc. It's really fast, it's cheap, and I can get back to the data I need to. It's also not optimized for making things painful. Ok? It's designed to be easy and stuff.

Personally, I have no plans to track my /etc with git, but I recently started using git to track /var/named (BIND configs). Given what Randal has to say above, should I stop using git for this purpose? Is there a downside, a problem I'm not anticipating, a gotcha? So far everything is working just as I expect, and I've had no problems, but I actually hesitated to start using git to track /var/named because of the warning above.

I'm influenced by the scm_track_enabled feature of Cobbler which says "enables a trigger which version controls all changes to /var/lib/cobbler when add, edit, or sync events are performed. This can be used to revert to previous database versions, generate RSS feeds, or for other auditing or backup purposes. git is the recommend SCM for use with this feature." My use of git with /var/named is very similar to this.

(As a side note, I've never used RCS and can't imagine bothering to learn it, even if it is easy, when I already have a decent understanding of git.)

Specifically, I'm wondering about using git to track /var/named, but I welcome answers about best practices for using git to track directories like it.

In migrating an Apache web site from RHEL 5 to CentOS 5 I noticed Chinese Traditional (Big 5) fonts look fine on the old site, but are garbled on the new site.

In Firefox, I can get the fonts to display properly by clicking View -> Character Encoding -> and changing "Unicode (UTF-8" to "Chinese Traditional (Big 5)".

How can I tell Apache to set the character encoding properly?

Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized:

[root@fs-2 ~]# tail -18 /var/log/messages
May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen
May 5 16:54:35 fs-2 kernel: ata1: SError: { PHYRdyChg CommWake }
May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0)
May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset
May 5 16:54:45 fs-2 kernel: ata1: soft resetting link
May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0)
May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16)
May 5 16:54:55 fs-2 kernel: ata1: soft resetting link
May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0)
May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16)
May 5 16:55:05 fs-2 kernel: ata1: soft resetting link
May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0)
May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16)
May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps
May 5 16:55:40 fs-2 kernel: ata1: soft resetting link
May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16)
May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up
May 5 16:55:45 fs-2 kernel: ata1: EH complete

I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn't work:

[root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan
-bash: echo: write error: Invalid argument
[root@fs-2 ~]#
[root@fs-2 ~]# /root/rescan-scsi-bus.sh -l
[snip]
0 new device(s) found.
0 device(s) removed.
[root@fs-2 ~]#
[root@fs-2 ~]# ls /dev/sda
ls: /dev/sda: No such file or directory

I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting?

The operating system in question is RHEL5.3:

[root@fs-2 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5.3 (Tikanga)

The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS.

Here is the lscpi output:

[root@fs-2 ~]# lspci
00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2)
00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3)
00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3)
00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1)
00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2)
00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1)
00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2)
00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3)
00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3)
00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02)
04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06)
04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06)

Update: In perhaps a dozen cases, we've been forced to reboot servers because hot swap hasn't "just worked." Thanks for the answers to look more into the SATA controller. I've included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn't supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful.

The good news is that hot swap "just worked" today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output:

[root@www-1 ~]# lspci
00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2)
00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3)
00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3)
00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1)
00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2)
00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1)
00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3)
00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2)
00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3)
00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3)
00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control
00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration
00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map
00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller
00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control
00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control
03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02)
04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06)
04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06)
09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)

How can I tell which MySQL users have access to a database and what privileges they have?

I seem to be able to get this information from phpMyAdmin when I click "Privileges". . .

                 Users having access to "mydatabase"
User     Host       Type               Privileges              Grant
myuser1  %          database-specific  ALL PRIVILEGES          Yes
root     localhost  global             ALL PRIVILEGES          Yes
myuser2  %          database-specific  SELECT, INSERT, UPDATE  No

. . . but I'd like to know how to perform this query from the command line.

(phpMyAdmin often shows me the SQL syntax of the command it is executing, but I don't see it in this case.)

Please note that I'm not asking what grants a particular user has (i.e. "SHOW GRANTS for myuser1") but rather, given the name of a database, how do I determine which MySQL users have access to that database and what privileges they have? Basically, how can I get the chart above from the command line?