You can remove a user and their home directory, however to preserve their login, but disable it the easiest way is to change their shell to one that doesn’t exist, or /bin/false. /bin/nologin leaves a breadcrumb that someone else can tell that a human disabled the account.
# chsh -s /bin/nologin firedemployeersync -a --ignore-existing --remove-source-files src/ destAny existing files in the destination will not be overwritten. After it’s done, look in src to see what is also in destination, then diff to see which ones to manually keep, or quickly write a one-liner to compare time stamps and keep newer ones and overwrite older versions.
# usermod -a -G
#
# usermod -a -G netops jdoe During massive outages (which thankfully happen rarely), I like to keep my Nagios monitoring machines online and working. This is because I like to have a view of the servers with remaining problems, or processes that didn’t come back online correctly. However, I stop our MTA (postfix) on those servers, because I don’t want to receive texts and emails complaining about all the servers that are still down. Once the problem is resumed, I could just startup postfix, but lets take a look at the mailqueue:
# mailq 2>&1 | tail -1 | cut -d " " -f 5-
428 Requests.
Hmm… seems a bit high. If we start postfix again, guess how many text messages are going to wind up on my phone? Let’s drop all of the messages in the queue:
# postsuper -d ALL
postsuper: Deleted: 428 messagesNow we can start postfix without excessive messages being sent.
Alternatively, if the main MX relays go down for a period of time, you will see the mailqueue fill up with undelivered mail. After you bring the MXs back online, the mail may be sent to them immediately. Your MTA probably has an increasing retry interval, which could lead to a one hour delay or longer. Do this to attempt to relay all the mail in the queue:
# postqueue -fIt will try to reconnect immediately to the MX relay, and deliver all mail if it can.
I once had a migration project to move 40TB of data that needed to be moved from source to destination NFS volumes. Naturally, I went with rsync. This was basically the command for the initial transfers:
rsync -a --out-format="transfer:%t,%b,%f" --itemize-changes /mnt/srcvol /mnt/destvol >> /log/file.logPretty simple right? The logs are a simple csv file that looked like this:
transfer:2013/05/02 10:16:13,35291,mnt/srcvol/archive/foo/bar/barfoo/IMAGES/1256562131100.jpgThe customer asked for daily updates on progress. I said no problem, and this one liner takes care of it:
# grep transfer /log/file.log | awk -F "," '{if ($2!=0) i=i+$2; x++} END {print "total Gbytes: "i/1073741824"\ntotal files: "x}'
total Gbytes: 1153.29
total files: 123686From the rsync command above, the %t means timestamp (2013/05/02 10:16:13), the %b means bytes transferred (35291), and the %f means the whole file path. By adding up the %b column of output and counting how many times you added it, you get both the total bytes transferred and the total number of files transferred. Directories show up as 0 byte transfers so in awk we don’t count them. Also, I threw in the divide by 1073741824 (1024*1024*1024), which converts bytes to Gebibytes.
I ended up putting it in a shell script and adding options such as, just find transfers for a particular day/hour, better handling for the Gbytes number, rate calculation, and the ability to add logs from multiple data moving servers.
I had to copy the contents of a .iso file. It’s easy to mount it and see what’s in the iso.
# mkdir /mnt/iso
# mount -o loop VMware-VMvisor-Installer-5.1.0-799733.x86_64.iso /mnt/iso
# cd /mnt/disk
# ls
a.b00 ata_pata.v05 boot.cfg ima_qla4.v00 isolinux.bin misc_dri.v00 net_e100.v01 net_r816.v00 ohci_usb.v00 sata_sat.v02 scsi_bnx.v00 scsi_meg.v01 scsi_qla.v01 upgrade xlibs.v00
ata_pata.v00 ata_pata.v06 chardevs.b00 imgdb.tgz isolinux.cfg net_be2n.v00 net_enic.v00 net_r816.v01 safeboot.c32 sata_sat.v03 scsi_fni.v00 scsi_meg.v02 scsi_rst.v00 user.b00 xorg.v00
ata_pata.v01 ata_pata.v07 efi imgpayld.tgz k.b00 net_bnx2.v00 net_forc.v00 net_s2io.v00 sata_ahc.v00 sata_sat.v04 scsi_hps.v00 scsi_mpt.v00 s.v00 useropts.gz
ata_pata.v02 b.b00 efiboot.img ipmi_ipm.v00 mboot.c32 net_bnx2.v01 net_igb.v00 net_sky2.v00 sata_ata.v00 scsi_aac.v00 scsi_ips.v00 scsi_mpt.v01 tboot.b00 vmware-esx-base-osl.txt
ata_pata.v03 block_cc.v00 ehci_ehc.v00 ipmi_ipm.v01 menu.c32 net_cnic.v00 net_ixgb.v00 net_tg3.v00 sata_sat.v00 scsi_adp.v00 scsi_lpf.v00 scsi_mpt.v02 tools.t00 vmware-esx-base-readme
ata_pata.v04 boot.cat esx_dvfi.v00 ipmi_ipm.v02 misc_cni.v00 net_e100.v00 net_nx_n.v00 net_vmxn.v00 sata_sat.v01 scsi_aic.v00 scsi_meg.v00 scsi_qla.v00 uhci_usb.v00 weaselin.t00
#
Now the contents of /mnt/disk appear as if you had burned the .iso and put it in the CD drive.
If you want to find all symlinks on a file system or in a folder use this:
find . -type l -ls# sed -i '$d' file.txtBy default ssh runs on TCP port 22. If you have a ssh configured to listen on a non standard port, you may need a special option to make rsync connect to that port. I was writing a quick backup script for this worpress site, and ran into this issue. In my case I was trying to rsync to a remote server with ssh listening on 4590. You have to give rsync a special ssh option:
# rsync -a --rsh='ssh -p 4590' /srv/www/wp-uploads/ backupsite.com:/backups/wp/wp-uplodas
To find the 10 newest items in your home directory you can just use ls.
# cd
# ls -lt | head
total 1197116
-rw-r--r-- 1 fordodone fordodone 5353 2013-04-23 10:42 file1
-rw-r--r-- 1 fordodone fordodone 2945 2013-04-23 10:21 file2
drwxr-xr-x 2 fordodone fordodone 12288 2013-04-12 08:53 bin
-rw-r--r-- 1 fordodone fordodone 0 2013-03-27 08:45 file3
-rw------- 1 fordodone fordodone 90420 2013-03-23 09:03 file4
-rw-r--r-- 1 fordodone fordodone 83 2013-03-19 10:35 file5
-rw-r--r-- 1 fordodone fordodone 8683 2013-03-15 10:26 file6
-rw-r--r-- 1 fordodone fordodone 28628 2013-03-15 09:15 file7
-rw-r--r-- 1 fordodone fordodone 81303 2013-03-15 09:15 file8
You could even get more aggressive by throwing the recursive flag in. Simple, right? But what if you need to recurse a large number of files and directories on a storage system, say 123,000 directories and 37 million files. I think find might be the way to go.
This will find files modified in the last 24 hours:
# find . -type f -mtime -1 -lsfind doesn’t really provide granular control of searching for files with a certain modified time. If you just want to find files that have been modified today (i.e. since 12am) we can use the -newer flag. First touch a temporary file with a timestamp to compare to files you want to find. In this case we make a date string of 04240000, or today at 00:00, and touch a file with that timestamp. Then use find to find files that are newer than the timestamp of the file you just touched.
# touch -t `date +%m%d0000` /tmp/compare
# find . -type f -newer /tmp/compare
(long output)
# rm /tmp/compare