HTF's questions

I would like to schedule a highstate to run every night but not in parallel. Is there a way to add batch option to the scheduling system?

Example:

schedule:
  highstate:
    enabled: True
    function: state.highstate
    maxrunning: 1
    when: 3:00am
    kwargs:
      batch: 1

Ideally I would like to also randomize the time when it runs. I guess I could schedule to run every two hours within one hour time range so it will run only once:

schedule:
  highstate:
    enabled: True
    function: state.highstate
    maxrunning: 1
    range:
      start: 3:00am
      end: 4:00am
    hours: 2
    kwargs:
      batch: 1

allow insecure wide links:

In normal operation the option wide links which allows the server to follow symlinks outside of a share path is automatically disabled when unix extensions are enabled on a Samba server. This is done for security purposes to prevent UNIX clients creating symlinks to areas of the server file system that the administrator does not wish to export.

Setting allow insecure wide links to true disables the link between these two parameters, removing this protection and allowing a site to configure the server to follow symlinks (by setting wide links to "true") even when unix extensions is turned on.

According to manual setting allow insecure wide links = yes should be enough to allow symlinks outside the shared path however it's not working for me unless I set unix extensions = no.

testparm is not even showing this variable?!

# testparm -s
Load smb config files from /etc/samba/smb.conf
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
Processing section "[Public]"
Loaded services file OK.
Server role: ROLE_STANDALONE
[global]
    workgroup = test
    server string = SambaBox
    syslog = 0
    log file = /var/log/samba/smb.log
    max log size = 50
    smb ports = 139
    socket options = TCP_NODELAY IPTOS_LOWDELAY SO_RCVBUF=65536 SO_SNDBUF=65536
    load printers = No
    printcap name = /dev/null
    disable spoolss = Yes
    show add printer wizard = No
    idmap config * : backend = tdb

[Public]
    comment = Public
    path = /data/Public
    valid users = smbguest
    create mask = 0644
    force create mode = 0644
    force directory mode = 0755
    map archive = No
    wide links = Yes

I have a CentOS 6 server with software RAID1 (2x3TB):

- sda

# parted /dev/sda unit s print
Model: ATA TOSHIBA DT01ACA3 (scsi)
Disk /dev/sda: 5860533168s
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number  Start     End          Size         File system  Name  Flags
 1      2048s     1026047s     1024000s     ext4               boot
 2      1026048s  5860532223s  5859506176s                     raid

- sdb

# parted /dev/sdb unit s print
Model: ATA TOSHIBA DT01ACA3 (scsi)
Disk /dev/sdb: 5860533168s
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number  Start     End          Size         File system  Name  Flags
 1      2048s     1026047s     1024000s     ext4               boot
 2      1026048s  5860532223s  5859506176s                     raid

- md[0-1]

# cat /proc/mdstat 
Personalities : [raid1] 
md0 : active raid1 sdb1[1] sda1[0]
      511936 blocks super 1.0 [2/2] [UU]

md1 : active raid1 sdb2[1] sda2[0]
      2929621824 blocks super 1.1 [2/2] [UU]
      bitmap: 1/22 pages [4KB], 65536KB chunk

unused devices: <none>

• md0 is mounted on /boot
• md1 is used for physical volume with 'root' and 'swap' logical volumes

I would like to use the same partitioning layout on CentOS 7 however anaconda is complaining about missing 'biosboot' partition:

Your BIOS-based system needs a special partition to boot from a GPT disk lable. To continue, please create a 1MB 'biosboot' type partition.

Is there a way to aviod this? I was thinking to create a two separate 'biosboot' partitions on each disk to mirror both HDDs.

The SSH console is timing out and I'm not able to execute any commands.

I've noticed that I can execute commands remotely but when I try to allocate TTY it hangs:

Works:

$ ssh [email protected] "uname -a"
Linux example.com 2.6.32-504.el6.x86_64 #1 SMP Tue Sep 16 01:56:35 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

Hangs:

$ ssh -t [email protected] "uname -a"
$ ssh [email protected] "dmesg"
tty_ldisc_hangup: waiting (sshd) for pts1 took too long, but we keep waiting...

• OS: RHEL 6.6
• Kernel: kernel-2.6.32-504.el6.x86_64

Is there a way to scan for free IPs on the network? I use nmap -sP 192.168.1.0/24 but this actually shows hosts that are up.

I would like to log SFTP commands to a separate file however it works only for root but not for chrooted user:

# cat /etc/ssh/sshd_config
...
Subsystem       sftp    internal-sftp -l INFO
Match Group user1
   ChrootDirectory /chroot
   ForceCommand internal-sftp -l INFO
   AllowTcpForwarding no
   X11Forwarding no

-

Default facility is AUTH according to man page

# cat /etc/rsyslog.d/sshd.conf
auth.* /var/log/sftp.log

-

tail -F /var/log/secure /var/log/sftp.log

==> /var/log/secure <==
Dec 27 12:35:09 lab sshd[43014]: Accepted publickey for root from 192.168.1.100 port 44706 ssh2
Dec 27 12:35:09 lab sshd[43014]: pam_unix(sshd:session): session opened for user root by (uid=0)
Dec 27 12:35:09 lab sshd[43014]: subsystem request for sftp

==> /var/log/sftp.log <==
Dec 27 12:35:09 lab internal-sftp[43016]: session opened for local user root from [192.168.1.100]
Dec 27 12:35:10 lab internal-sftp[43016]: opendir "/root/"
Dec 27 12:35:10 lab internal-sftp[43016]: closedir "/root/"
Dec 27 12:35:27 lab internal-sftp[43016]: session closed for local user root from [192.168.1.100]

==> /var/log/secure <==
Dec 27 12:35:27 lab sshd[43014]: Received disconnect from 192.168.1.100: 11: disconnected by user
Dec 27 12:35:27 lab sshd[43014]: pam_unix(sshd:session): session closed for user root
Dec 27 12:35:31 lab sshd[43017]: Accepted password for user1 from 192.168.1.100 port 44708 ssh2
Dec 27 12:35:31 lab sshd[43017]: pam_unix(sshd:session): session opened for user user1 by (uid=0)
Dec 27 12:35:31 lab sshd[43019]: subsystem request for sftp
Dec 27 12:35:31 lab sshd[43020]: session opened for local user user1 from [192.168.1.100]
Dec 27 12:35:31 lab sshd[43020]: opendir "/"
Dec 27 12:35:31 lab sshd[43020]: closedir "/"

EDIT: Mon Dec 30 11:40:18 GMT 2013

System: CentOS 6.5

I added the following options however events are still logged to the /var/log/secure log file:

# id user1
uid=501(user1) gid=501(user1) groups=501(user1)
# mkdir /chroot/dev
# cat /etc/rsyslog.d/sshd.conf
$AddUnixListenSocket /chroot/dev/log
auth.* /chroot/dev/sftp.log
# service rsyslog restart
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
# ll /chroot/dev/
total 0
srw-rw-rw- 1 root   root   0 Dec 30 11:44 log
-rw------- 1 nobody nobody 0 Dec 30 11:39 sftp.log

Is there a way to identify a parent template for VMs. I've got a few VMs created from different templates and I need to confirm source template.

I've tried blkid and dmidecode -s system-uuid but it looks like these IDs are re-generated for new VMs.

Regards

The following errors appear on the NFS server, could you please advise how I can fix this?

Details:

System: CentOS release 6.4, NFS: nfs-utils-1.2.3-36

# cat /etc/idmapd.conf

[General]
Domain = domain.com

[Mapping]
Nobody-User = nobody
Nobody-Group = nobody

[Translation]
Method = nsswitch

Sep  3 08:25:28 snode1 rpc.idmapd[1382]: nss_getpwnam: name '0' does not map into domain 'domain.com'
Sep  3 08:25:29 snode1 rpc.idmapd[1382]: nss_getpwnam: name '500' does not map into domain 'domain.com'

EDIT: 03 Sep 2013 10:41

Please note that I'm using NFSv4 and these errors appear on NFS server only (not NFS clients).

Server:

# cat /etc/sysconfig/nfs

MOUNTD_NFS_V2="no"
MOUNTD_NFS_V3="no"
...
RPCNFSDARGS="-N 2 -N 3"

Clients:

# cat /etc/fstab

server:/     /data  nfs4    defaults,hard,intr,timeo=15,_netdev,noatime,nodiratime,nosuid    0 0

Edit: Wed Jun 11 14:52:50 BST 2014

# getent passwd "0" | cut -d: -f1
root
# getent passwd "500" | cut -d: -f1
user1

-

# grep "^passwd" /etc/nsswitch.conf 
passwd:     files

According to Red Hat docs 'rpcbind' is not required any more:

Because protocol support has been incorporated into the v4 protocol, NFSv4 has no interaction with the portmap, rpc.lockd, and rpc.statd daemons. NFSv4 listens on the well-known TCP port 2049, which eliminates the need for portmap interaction. The mounting and locking protocols have been incorporated into the V4 protocol which eliminates the need for interaction with rpc.lockd and rpc.statd. The rpc.mountd daemon is still required on the server, but is not involved in any over-the-wire operations.

however I'm not able to start NFS demon when 'rpcbind' service is not running:

# service nfs start
Starting NFS services:                                     [  OK  ]
Starting NFS quotas: Cannot register service: RPC: Unable to receive; errno = Connection refused
rpc.rquotad: unable to register (RQUOTAPROG, RQUOTAVERS, udp).
                                                           [FAILED]
Starting NFS mountd:                                       [  OK  ]
Starting NFS daemon: rpc.nfsd: writing fd to kernel failed: errno 111 (Connection refused)
rpc.nfsd: unable to set any sockets for nfsd
                                                           [FAILED]

I've disabled NFS v2 and v3:

# grep -v "^#" /etc/sysconfig/nfs
MOUNTD_NFS_V2="no"
MOUNTD_NFS_V3="no"
RPCNFSDARGS="-N 2 -N 3"

Could you please confirm what services are required/essential on server and client from these listed below (basically I would like to disable services which are not needed):

# rpm -ql nfs-utils | grep 'init.d'
/etc/rc.d/init.d/nfs
/etc/rc.d/init.d/nfslock
/etc/rc.d/init.d/rpcgssd
/etc/rc.d/init.d/rpcidmapd
/etc/rc.d/init.d/rpcsvcgssd

Could you please help me to understand 'direct-io-mode' in GlusterFS.

I'm getting better read results with direct I/O mode disabled - is it mean that in disabled mode it's writing/reading from cache - is it a system cache or GlusterFS cache? What's the recommended method? I'm using 4 nodes with distributed-replicated volume for web serving:

Write: dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
echo 3 > /proc/sys/vm/drop_caches
Read: dd if=tempfile of=/dev/null bs=1M count=1024
Read-Read: dd if=tempfile of=/dev/null bs=1M count=1024

Write           Read            Re-Read
67.5 MB/s       94.9 MB/s       94.6 MB/s   direct-io-mode=enabled
65.8 MB/s       230 MB/s        226 MB/s    direct-io-mode=disabled

I would like to check how many file descriptors are actually used:

cat /proc/sys/fs/file-nr 
12750   0   753795

The first column (12750) indicates the number of file descriptors allocated since boot.

I would like to know why the number from the following command is different (assuming this one liner is returning the correct value:

for pid in $(lsof | awk '{ print $2 }' | uniq); do find /proc/$pid/fd/ -type l 2>&1 | grep -v "No"; done | wc -l

11069

I've noticed high memory usage on the server. Details:

OS: CentOS 6.3 - x86_64

Web server: Nginx with PHP-FPM

The server is generating PDF documents so the traffic is minimum.

top:

# top -b -n 1 -a
top - 10:04:51 up 21 days, 18:57,  1 user,  load average: 0.00, 0.00, 0.00
Tasks:  92 total,   1 running,  91 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.3%us,  0.2%sy,  0.0%ni, 99.6%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   3923092k total,  3720380k used,   202712k free,   133904k buffers
Swap:  4194296k total,       12k used,  4194284k free,   147404k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                     
15855 www-data  20   0  199m 4952 2128 S  0.0  0.1   0:00.06 php-fpm                                                                                     
15853 www-data  20   0  199m 4940 2028 S  0.0  0.1   0:00.06 php-fpm                                                                                     
15850 www-data  20   0  199m 4928 2020 S  0.0  0.1   0:00.05 php-fpm                                                                                     
15851 www-data  20   0  199m 4888 2020 S  0.0  0.1   0:00.06 php-fpm                                                                                     
15852 www-data  20   0  199m 4852 2020 S  0.0  0.1   0:00.06 php-fpm                                                                                     
15857 www-data  20   0  198m 4716 2020 S  0.0  0.1   0:00.06 php-fpm                                                                                     
17553 root      20   0 97816 3860 2924 S  0.0  0.1   0:00.03 sshd                                                                                        
15849 root      20   0  198m 3460 1072 S  0.0  0.1   0:00.12 php-fpm                                                                                     
13441 nginx     20   0 65608 2968 1604 S  0.0  0.1   0:02.06 nginx                                                                                       
13440 nginx     20   0 65608 2964 1600 S  0.0  0.1   0:01.87 nginx                                                                                       
17561 root      20   0  105m 1944 1488 S  0.0  0.0   0:00.01 bash                                                                                        
 1150 xfs       20   0 20980 1784  704 S  0.0  0.0   0:00.13 xfs                                                                                         
15863 root      20   0  179m 1424 1028 S  0.0  0.0   0:00.00 rsyslogd                                                                                    
    1 root      20   0 19224 1360 1088 S  0.0  0.0   0:17.96 init                                                                                        
 1201 nrpe      20   0 40928 1288  704 S  0.0  0.0   3:57.64 nrpe                                                                                        
13226 root      20   0  114m 1216  612 S  0.0  0.0   0:00.01 crond                                                                                       
 6691 root      20   0 64068 1156  488 S  0.0  0.0   0:09.59 sshd                                                                                        
13439 root      20   0 65104 1128  292 S  0.0  0.0   0:00.00 nginx                                                                                       
19026 root      20   0 15040 1116  844 R  0.0  0.0   0:00.00 top                                                                                         
  451 root      16  -4 11052 1096  316 S  0.0  0.0   0:00.02 udevd                                                                                       
 1174 root      18  -2 11048 1064  288 S  0.0  0.0   0:00.00 udevd                                                                                       
 1175 root      18  -2 11048 1064  288 S  0.0  0.0   0:00.00 udevd                                                                                       
 1065 root      16  -4 93168  824  560 S  0.0  0.0   0:16.00 auditd                                                                                      
 1165 root      20   0  4056  564  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
 1167 root      20   0  4056  564  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
 1169 root      20   0  4056  564  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
 1171 root      20   0  4056  564  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
 1163 root      20   0  4056  560  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
 1176 root      20   0  4056  560  480 S  0.0  0.0   0:00.00 mingetty                                                                                    
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd                                                                                    
    3 root      RT   0     0    0    0 S  0.0  0.0   0:11.75 migration/0                                                                                 
    4 root      20   0     0    0    0 S  0.0  0.0  44:30.28 ksoftirqd/0                                                                                 
    5 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0                                                                                 
    6 root      RT   0     0    0    0 S  0.0  0.0   0:03.51 watchdog/0                                                                                  
    7 root      RT   0     0    0    0 S  0.0  0.0   0:11.63 migration/1                                                                                 
    8 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/1                                                                                 
    9 root      20   0     0    0    0 S  0.0  0.0  11:35.50 ksoftirqd/1                                                                                 
   10 root      RT   0     0    0    0 S  0.0  0.0   0:03.34 watchdog/1                                                                                  
   11 root      20   0     0    0    0 S  0.0  0.0   1:36.68 events/0                                                                                    
   12 root      20   0     0    0    0 S  0.0  0.0   1:50.57 events/1                                                                                    
   13 root      20   0     0    0    0 S  0.0  0.0   0:00.00 cgroup                                                                                      
   14 root      20   0     0    0    0 S  0.0  0.0   0:00.00 khelper                                                                                     
   15 root      20   0     0    0    0 S  0.0  0.0   0:00.00 netns                                                                                       
   16 root      20   0     0    0    0 S  0.0  0.0   0:00.00 async/mgr                                                                                   
   17 root      20   0     0    0    0 S  0.0  0.0   0:00.00 pm                                                                                          
   18 root      20   0     0    0    0 S  0.0  0.0   0:07.86 sync_supers                                                                                 
   19 root      20   0     0    0    0 S  0.0  0.0   0:10.38 bdi-default                                                                                 
   20 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kintegrityd/0                                                                               
   21 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kintegrityd/1                                                                               
   22 root      20   0     0    0    0 S  0.0  0.0   0:04.35 kblockd/0                                                                                   
   23 root      20   0     0    0    0 S  0.0  0.0   0:04.18 kblockd/1                                                                                   
   24 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kacpid                                                                                      
   25 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kacpi_notify                                                                                
   26 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kacpi_hotplug                                                                               
   27 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ata/0                                                                                       
   28 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ata/1                                                                                       
   29 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ata_aux                                                                                     
   30 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksuspend_usbd                                                                               
   31 root      20   0     0    0    0 S  0.0  0.0   0:00.00 khubd                                                                                       
   32 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kseriod                                                                                     
   33 root      20   0     0    0    0 S  0.0  0.0   0:00.00 md/0                                                                                        
   34 root      20   0     0    0    0 S  0.0  0.0   0:00.00 md/1                                                                                        
   35 root      20   0     0    0    0 S  0.0  0.0   0:00.00 md_misc/0                                                                                   
   36 root      20   0     0    0    0 S  0.0  0.0   0:00.00 md_misc/1                                                                                   
   37 root      20   0     0    0    0 S  0.0  0.0   0:00.48 khungtaskd                                                                                  
   38 root      20   0     0    0    0 S  0.0  0.0   1:07.52 kswapd0                                                                                     
   39 root      25   5     0    0    0 S  0.0  0.0   0:00.00 ksmd                                                                                        
   40 root      39  19     0    0    0 S  0.0  0.0   0:22.00 khugepaged                                                                                  
   41 root      20   0     0    0    0 S  0.0  0.0   0:00.00 aio/0                                                                                       
   42 root      20   0     0    0    0 S  0.0  0.0   0:00.00 aio/1                                                                                       
   43 root      20   0     0    0    0 S  0.0  0.0   0:00.00 crypto/0                                                                                    
   44 root      20   0     0    0    0 S  0.0  0.0   0:00.00 crypto/1                                                                                    
   49 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthrotld/0                                                                                  
   50 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthrotld/1                                                                                  
   52 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kpsmoused                                                                                   
   53 root      20   0     0    0    0 S  0.0  0.0   0:00.00 usbhid_resumer                                                                              
   83 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kstriped                                                                                    
  233 root      20   0     0    0    0 S  0.0  0.0   0:00.00 scsi_eh_0                                                                                   
  234 root      20   0     0    0    0 S  0.0  0.0   0:00.00 scsi_eh_1                                                                                   
  321 root      20   0     0    0    0 S  0.0  0.0   0:00.00 virtio-blk                                                                                  
  359 root      20   0     0    0    0 S  0.0  0.0   0:03.24 kdmflush                                                                                    
  360 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kdmflush                                                                                    
  380 root      20   0     0    0    0 S  0.0  0.0   0:20.64 jbd2/dm-0-8                                                                                 
  381 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ext4-dio-unwrit                                                                             
  382 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ext4-dio-unwrit                                                                             
  694 root      20   0     0    0    0 S  0.0  0.0   0:00.00 vballoon                                                                                    
  697 root      20   0     0    0    0 S  0.0  0.0   0:00.00 virtio-net                                                                                  
  818 root      20   0     0    0    0 S  0.0  0.0   0:00.00 jbd2/vda1-8                                                                                 
  819 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ext4-dio-unwrit                                                                             
  820 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ext4-dio-unwrit                                                                             
  851 root      20   0     0    0    0 S  0.0  0.0   0:06.96 kauditd                                                                                     
 1013 root      20   0     0    0    0 S  0.0  0.0   0:15.45 flush-253:0

ps:

# ps aux --sort -vsz | head
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
www-data 13213  0.0  0.1 204416  4772 ?        S    08:28   0:00 php-fpm: pool default
www-data 13214  0.0  0.1 204416  4776 ?        S    08:28   0:00 php-fpm: pool default
www-data 13215  0.0  0.1 204416  4832 ?        S    08:28   0:00 php-fpm: pool default
www-data 13216  0.0  0.1 204416  4776 ?        S    08:28   0:00 php-fpm: pool default
www-data 13218  0.0  0.1 204416  4956 ?        S    08:28   0:00 php-fpm: pool default

free:

#free -m
             total       used       free     shared    buffers     cached
Mem:          3831       3530        300          0        130        143
-/+ buffers/cache:       3256        574
Swap:         4095          0       4095

When I stooped Nginx, PHP-FPM the memory usage was still the same.

Could you help me to investigate what is consuming the memory on the system?

Regards

I'm trying to configure phpMyAdmin so I've set the flowing location in Nginx however it apends the "pma" to the root directory:

2012/08/14 13:59:49 [error] 10151#0: *2 "/usr/share/phpMyAdmin/pma/index.php" is not found (2: No such file or directory), client: 192.168.1.2, server: domain.com, request: "GET /pma/ HTTP/1.1", host: "192.168.1.24"

Config:

location ^~ /pma {
            root /usr/share/phpMyAdmin;

        location ~ \.php$ {
            root /usr/share/phpMyAdmin;
            fastcgi_pass unix:/var/run/php-fpm/www.sock;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            include fastcgi_params;
            fastcgi_param HTTPS on;
        }

## HTTP to HTTPS redirect
server {
    listen  80;
    root  /var/empty;
    server_name domain.com;
    rewrite ^ https://domain.com$request_uri permanent;
    }


server {

    listen      443 default_server ssl;
    root        /var/www/html;
    index index.php index.html index.htm;
    server_name domain.com;

    location / {
        try_files $uri $uri/ /index.php?$args;

    }


    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php-fpm/www.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
    fastcgi_param HTTPS on;
    }

## phpMyAdmin
    location ^~ /pma  {
    alias /usr/share/phpMyAdmin/;
       try_files $uri $uri/ /index.php;

    location ~ ^/pma(.+\.php)$ {
    fastcgi_pass unix:/var/run/php-fpm/www.sock;
    fastcgi_index index.php;
    alias /usr/share/phpMyAdmin$1;
    fastcgi_param SCRIPT_FILENAME /usr/share/phpMyAdmin$1;
    include fastcgi_params;
    fastcgi_param HTTPS on;

    try_files $uri $uri/ /index.php?q=$request_uri;
    }
    }

## deny access to .htaccess files, if Apache's document root concurs with nginx's one
    location ~ /\. {
    access_log off;
    log_not_found off;
    deny  all;
    }

#serve static files directly
location ~* \.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|mid|midi|wav|bmp|rtf|js|swf|flv|mp3)$ {
    access_log off;
    log_not_found off;
    expires 2w;
    add_header Pragma "public";
        add_header Cache-Control "public, must-revalidate, proxy-revalidate";
    }

}

I currently have Nagios installation for monitoring various systems (mainly Linux). I would like to implement some graphing tool for historical data (CPU, memory, disk usage, web server QPS etc). I've tried Nagiosgrpah however it's not reliable and very limited.

I would like to try Cacti but I'm not sure what's the recommenced/secure way to pull the data from the remote servers. Is there some agent that needs to be installed on the monitored machine?

I've came across other tools like Ganglia and Graphite.

Could you recommend any of these tools in my case?

Regards

I've got two options (return and rewrite) for redirection and I'm not sure which is recommended for performance, SEO, etc:

## Redirect from non-www to www
server {
        server_name example.com;
        # Option 1
        return 301 $scheme://$host$request_uri;

        # Option 2
        rewrite ^ http://$host$request_uri? permanent;
    }

## Default server config

server {
        ...
        listen      192.168.1.1:80 default_server;
        root        /www;
        server_name www.example.com;

Option 2 seems to work with curl but it's not redirecting when called by a browser and the return code is that of a temporary redirect despite the rewrite directive being set to permanent:

 curl -I example.com
 HTTP/1.1 302 Moved Temporarily
 Server: nginx
 ...
 Location: http://www.example.com/
 ...

I would like to monitor the number of MySQL databases with Nagios. I've installed the official Nagios plugins.

I'm using 'check_mysql_query':

./check_nrpe -H 192.168.1.10 -c check_mysql_query

Nagios agent:

command[check_mysql_query]=/usr/lib64/nagios/plugins/check_mysql_query -d mysql -q "select count(*) from information_schema.SCHEMATA where schema_name not in ('mysql','information_schema');" -w 100 -c 150

I had to add client credentials to 'my.cnf' file.

Questions:

1. Is there any better/secure solution for this?

2. What's the minimum MySQL required privileges to run this command:

select count(*) from information_schema.SCHEMATA where schema_name not in ('mysql','information_schema');

I would like to redirect admin subdirectory to a subdomain. I tried to create this rule for Nginx however it's not working:

location ^~ /admin/ {
        rewrite ^/admin(.*) http://admin.example.com$uri permanent;
     }

Thank you Regards

What's the relation between:

innodb_buffer_pool_size and query_cache_*

Both are use for caching queries but what's the difference? Can I use both?

Thank you

I've got MySQL Master/Slave setup and I've noticed the following warnings in the mysql log files on both servers:

[Warning] IP address 'xxx.xxx.xxx.xxx' could not be resolved: Name or service not known

I've checked and the DNS lookups works fine and most of these IPs are from China.

I planning to limit access on port 3306 on the firewall however could you please help me to understand what they are trying to do. Are they just trying to connect to the MySQL server. Where I can look for some more details.

Thanks

What's the secure/proper way of restarting the MySQl slave server. I need to reboot the machine in order to update the kernel and apply some configuration changes.

I've tested it on my lab and unfortunately it didn't work properly:

1. I powered down slave server.
2. I've created new database with one simple table on the master server
3. I powered up the slave server (I haven't noticed any errors in the logs) The slave server has the correct master log position but there is no data created on the master while the slave was down. The master log position is updated when i create new data on the master but it's not appear on the slave?

I'm wondering if I should make any extra steps before I reboot the server, like "SLAVE STOP;" etc.

I have also another question regarding Percona Xtradb backup. When this script is running on the slave it's going behind the master (The I/O is not high and I've set --throttle option anyway)

What's the maximum value that the slave server can go behind the master and it still will be able to catch up with master?