Ramblings of yet another Sysadmin
Unless the archive is totally foobar one way is to use this quick command
pax -v -r * < /path/to/archive
This will restore your archive to the paths in the archive (ie /home/user will be restored to that path) if you need different options man pax is your new friend.
I am going to start a new section of Linux CLI foo that you may or may not know about. Many of these will be faster ways of doing things or getting information in a slightly different fashion. Many are old favorites of mine that I just wanted to share in case they help someone else.
Now without further ado the first command is :
ip -s l
short for ip stats list this gives a fast overview of your interfaces and the types of packets that have been going through them. Output looks like this :
[root@pbnj lisa11]# ip -s l
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
RX: bytes packets errors dropped overrun mcast
1084866683 400954 0 0 0 0
TX: bytes packets errors dropped carrier collsns
1084866683 400954 0 0 0 0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:30:48:61:c7:64 brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped overrun mcast
552827144 1541759 0 0 0 0
TX: bytes packets errors dropped carrier collsns
1428902993 1445402 0 0 0 0
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
link/ether 00:30:48:61:c7:65 brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped overrun mcast
0 0 0 0 0 0
TX: bytes packets errors dropped carrier collsns
0 0 0 0 0 0
More information on interface stats can be found via:
ethtool -S $DEVICE
ifconfig $device (or just ifconfig for all devices)
ifconfig -s $DEVICE
among others….
If you are running tuned these settings will likely “undo” themselves. I found this out the hardway ;)
Update: If you are running a old firmware (older than CC34) update !! More on the update are on Seagates page and here http://niallbest.com/seagate-2tb-st32000542as-cc35-firmware-upgrade/. To find your firmware use `hdparm -I /dev/sd[a-z] | grep Firmware`.
I was noticing Samba being slow when I would access it from time to time. It would always work but man was it annoying. Since this was right after I added some new 2TB drives to my LVM/Software Raid 1 array I figured I would check to see if power management had been the cause for my pain. Sure enough I found this :
[root@stardust ~]# hdparm -C /dev/sd[a-z] | sed ‘/^$/d’
/dev/sda:
drive state is: active/idle
/dev/sdb:
drive state is: standby
/dev/sdc:
drive state is: active/idle
/dev/sdd:
drive state is: active/idle
/dev/sde:
drive state is: standby
/dev/sdf:
drive state is: active/idle
/dev/sdg:
drive state is: active/idle
To which I answered with :
hdparm -B 255 -S 0 -K 1 /dev/sd[b,e]
and wala all was happy again and my delay was gone!
/dev/sda:
drive state is: active/idle
/dev/sdb:
drive state is: active/idle
/dev/sdc:
drive state is: active/idle
/dev/sdd:
drive state is: active/idle
/dev/sde:
drive state is: active/idle
/dev/sdf:
drive state is: active/idle
/dev/sdg:
drive state is: active/idle
The new drives were Seagate “Green” drives (ST32000542AS) so I cant blame them for shipping with aggressive power save settings. If you need to check what your power save settings are you can do something like :
for d in /dev/sd[a-z]; do echo $d; hdparm -I $d | grep level; done
/dev/sda
/dev/sdb
Advanced power management level: disabled
/dev/sdc
/dev/sdd
/dev/sde
Advanced power management level: disabled
/dev/sdf
/dev/sdg
HDIO_DRIVE_CMD(identify) failed: Invalid exchange
The /dev/sdg device is a USB drive and they dont play nice with hdparms commands usually.
Found this URL on a website pop-up spam :
http://weeklycontestwinner.s3.amazonaws.com/***********
No I do not recommend clicking on it (but you might get something free …..yeah right). The interesting thing here is the use of the cloud for quick and easy spammer/phishing/whatever-else-malware sites. Futher proof that :
A: Amazon isnt doing good policing of content.
B: The Internet’s underbelly is light years ahead of most IT departments in understanding how to use the cloud.
I could keep going ..just wanted to share something I have seen growing in use over the last year.
# uptime
15:05:59 up 271 days, 22:45, 2 users, load average: 1789.01, 2333.21, 3025.28
This was a managed system where qmail ran away with a high remote concurrency set (5000). System was very responsive despite the load .
I am usually not one to get involved with politics and this matter is no different. Whichever way you lean on this DNS matter I feel it is a good chance to learn more about what options are out there. If you need to catchup here is some reading:
http://torrentfreak.com/bittorrent-based-dns-to-counter-us-domain-seizures-101130/
http://hotair.com/archives/2010/11/27/doj-seizes-domain-names-of-more-than-70-websites-suspected-of-piracy/
http://da.feedsportal.com/c/270/f/470440/s/1023e6ae/l/0Lnews0Btechworld0N0Csme0C32510A10A0Ctorrent0Efinder0Eshut0Edown0Eby0Eus0Eagencies0C0Dolo0Frss/ia1.htm
These show how government is getting more involved in DNS which is the core of how we do things on the net. This opens the door for further understanding/learning of the other options that are available on the net.
One of these is a great project for a open DNS system:
What OpenNIC are doing already and the push to a torrent driven DNS system with the .p2p extension are making the DNS world get interesting!
So what you have here is a change that is causing “ripples” all over the ‘net that could lead to major/minor changes into how DNS is done. Whatever you think will become of this it is going to be interesting to watch play out.
PRC | sys 0.22s | user 0.01s | | | #proc 158 | #zombie 0 | clones 0 | | | #exit 0 |
CPU | sys 1% | user 0% | irq 131% | | idle 668% | | wait 0% | | steal 0% | guest 0% |
cpu | sys 0% | user 0% | irq 80% | | idle 20% | | cpu007 w 0% | | steal 0% | guest 0% |
cpu | sys 0% | user 0% | irq 52% | | idle 48% | | cpu006 w 0% | | steal 0% | guest 0% |
cpu | sys 1% | user 0% | irq 0% | | idle 99% | | cpu004 w 0% | | steal 0% | guest 0% |
cpu | sys 0% | user 0% | irq 0% | | idle 100% | | cpu000 w 0% | | steal 0% | guest 0% |
CPL | avg1 0.07 | avg5 0.10 | | avg15 0.07 | | csw 3209 | intr 65623 | | | numcpu 8 |
MEM | tot 5.8G | free 5.4G | cache 185.4M | dirty 0.0M | buff 91.2M | slab 33.8M | | | | |
SWP | tot 2.2G | free 2.2G | | | | | | | vmcom 136.4M | vmlim 5.1G |
NET | transport | tcpi 3 | tcpo 3 | udpi 0 | udpo 0 | tcpao 0 | tcppo 0 | tcprs 0 | tcpie 0 | udpip 0 |
NET | network | ipi 438568 | ipo 438568 | ipfrw 0 | deliv 438569 | | | | icmpi 438565 | icmpo 438565 |
NET | eth0 70% | pcki 438531 | pcko 438566 | si 70 Mbps | so 50 Mbps | coll 0 | erri 0 | erro 0 | drpi 0 | drpo 0 |
PID RUID EUID THR SYSCPU USRCPU VGROW RGROW RDDSK WRDSK ST EXC S CPUNR CPU CMD 1/1
24 root root 1 0.18s 0.00s 0K 0K 0K 0K – - S 7 6% ksoftirqd/7
4314 root root 1 0.01s 0.01s 0K 0K 0K 0K – - S 0 1% atop
3727 root root 1 0.02s 0.00s 0K 0K 0K 0K – - S 7 1% kondemand/7
7825 root root 1 0.01s 0.00s 0K 0K 0K 0K – - R 4 0% atop
7135 root root 1 0.00s 0.00s 0K 0K 0K 0K – - S 7 0% sshd
This was created with several `ping -s 1 -q -f $IP` commands across several systems. The CPU is :
Intel(R) Xeon(R) CPU W3530 @ 2.80GHz
What can I say , I am impressed ! I am going to try and max it out and see what it can do all out! This is a HUGE jump from our old P4 based firewall that barfed at 80-100K pps inbound!
Had to do a quick test of a Magento server getting ready for production recently. Being a big fan of Apaches Worker MPM (even when using PHP with ZTS) I thought i would test their recommended settings for Prefork vs one of my homebrew Worker configs. The results can be found on my wiki at http://misterx.org/wiki/index.php/Worker_vs_prefork_MPM.
