How to find which hard drives a LVM volume uses to decide which volume will be affected if a disk failes.
You can use lvdisplay with the --maps option to display the the mapping of logical extents to physical volumes and physical extents:
# lvdisplay --maps
To map physical extents to logical extents, use
# pvs --segments -o+lv_name,seg_start_pe,segtype
Vim is pretty fast and powerful. However, the core of Vim is (yet) single-threaded (some discussions and tries on porting Vim to be multi-threading, but not yet there). This means some functions that are slow will block Vim there and you have to wait for it. While Vim is fast, some plugins are not. When…
Admins usually need to generate some passwords for others, such as when creating a new user in a Linux system. How to generate a password in Shell on Linux? Several possible and short methods. Here, we generate a password of length 8. Using pwgen: $ pwgen 8 1 dao3PaW9 Password based on base64 (note that…
For local filesystems, root usually has full access (read/write) to directories/files inside of it. But for NFS directory mounted from network, root usually has no permission to write to directories or files within the NFS directory. How to make root act similarly in an NFS directory to the behavior in local directories? The reason that…
I have a text file with many lines of text. In Linux, how to sort the lines by their length? You can make use of awk together with the sort program like awk ‘{ print length(), $0 | “sort -n” }’ /path/to/text/file Here, we use awk to calculate the text length and sort -n to…
Here is a list of tutorials for learning how to write MapReduce programs on Hadoop, the opensource MapReduce implementation with HDFS. MapReduce Tutorials The official tutorial on Hadoop MapReduce framework: http://hadoop.apache.org/docs/r1.0.4/mapred_tutorial.html. Yahoo! Hadoop Tutorial A comprehensive tutorial on Hadoop from Yahoo! Developer Network: http://developer.yahoo.com/hadoop/tutorial/. More about MapReduce To better understand the design behind MapReduce, it…
I want to submit my paper to NAS 2015 but I am confused about its double-blind review 盲审又包括单盲审（Single-Blind Peer Review, SBPR）和双盲审（Double-Blind Peer Review, DBPR）。双盲审是审者与作者之间互相都不知道彼此身份的匿名评审。在双盲审的过程中，中间组织者的规范和保密工作很重要。单盲审一般是审者知道作者的身份，而作者不知道审者是谁。 计算机有不少会议实行双盲评审。 Reference: http://emuch.net/html/201104/3022021.html Read more: When should the authors anonymize themselves in a paper submitted to a conference for review? How to write paper reviews? How to convert A4 paper format…