When you write your master thesis (in Chinese) on windows, you may have following worries. a, Be afraid your master thesis is lost (or can not be accessed) when hard disk/udisk is broken (or something other viruses). b, Keep master thesis availability (7×24) and safety. c, Do not want anyone else to access it before
Read more
Tag: Hard disk
mkfs refuses to make filesystem with message “is apparently in use by the system; will not make a filesystem here!”
Posted onI have a disk from another server installed on a new server. However, when I try to make a filesystem on it, mkfs reports # mkfs -t ext4 /dev/sdd1 mke2fs 1.42.8 (20-Jun-2013) /dev/sdd1 is apparently in use by the system; will not make a filesystem here! This is a new disk to the new server.
Read more
How to mount LVM volume from an external hard disk on CentOS?
Posted onOn Fedora, after inserting/plugging in an exteranl hard disk with LVM partitions on it, the partitions will appear under /dev like /dev/lvm-group/lvm-partition. However, on CentOS 6, the LVM volumes do not appear automatically. How to mount LVM partitions from an external hard disk on CentOS? What you need on CentOS is to activate the LVM
Read more
How to erase disk partitions on U disks on Windows?
Posted onHow to erase disk partitions on U disks on Windows? Check the HDD LLF low level format tool: http://hddguru.com/software/HDD-LLF-Low-Level-Format-Tool/ It is free for personal usage. Run it as Adminiatrator and you can choose to erase partitions and MBR on the U disks. Be careful that the operation is is recoverable.
How to delete a disk from a LVM group while keeping the data
Posted onThis is the scenario: I want to remove a old hard disk which is a LVM PV and contains data. There is free space available on other PVs in the VG. It should move the data from the disk to be removed to other PVs and then remove the disk. The process to remove sdb
Read more
How to find the disk space left for a file on Linux
Posted onHow to find the disk space left for a file on Linux? For example, a program may append data to a file: /mnt/logs/app-log.log How to find which partition the app-log.log is on and how much disk space left on that partition? Use this command: $ df -B1 /mnt/logs/app-log.log | tail -1 | cut -d’ ‘
Read more
How to quickly find out failed disks’ SATA port in Linux? (how to map Linux disk names to SATA ports)
Posted onI find one disk failed on my server which have several ones installed. I know the disk’s name in Linux (e.g. sda, sdb). However, the Linux disk name to SATA port mapping does not follow the same order. Now, I want to find out the failed disks. How to quickly find out them and which
Read more
Making GPT Partition Table and Creating Partitions Using parted in Linux
Posted onMy best favorite disk partition table manipulation tools are cfdisk/fdisk on Linux. However, for large disks, cfdisk/fdisk (of the versions by this post is written) will just give up with a message suggesting GPT partition table format and using GNU parted like WARNING: The size of this disk is 6.0 TB (6001042391040 bytes). DOS partition
Read more
How to Set Up RAID0 in MegaRAID BIOS with New Disks
Posted onThe LSI MegaRAID is widely used like in IBM x3620M3 servers. This post introduces the process with screenshots of how to configure the new disks and set up RAID0 in the MegaRAID BIOS for reference by other and myself. It is illustrated with one example by adding a new 2TB hard disk and creating a
Read more
HP Compaq BIOS Crisis Recovery from a Failed BIOS Flashing Using a USB Flash Disk
Posted onI tried to flash my HP Compaq CQ35-240TX’s BIOS to F.15 but unfortunately failed. The computer turned to white screen. When I restarted (powered off then boot again), this is no response any more: the hard disk and caps lock’s LED keep blinding. I thought “Oh my God! I must send it to HP to
Read more
Extending a LVM Volume Group
Posted onWe introduced how to create a LVM group with two hard disk partitions, which the LVM group can be used for [[setting-up-lvm-backed-xen-domu|installing LVM backed Xen DomUs]]. The LVM volume can have large capacity from several hard disks. However, we may use all the disk space after some time and we may need to extend the
Read more
Setting Up Ubuntu DomU on Xen: Ubuntu 10.10 on Fedora Xen Dom0
Posted onSetting up Ubuntu 10.10 DomU on top of Fedora Xen Dom0 is introduced in this post. The process of setting up Ubuntu 10.10 DomU is the same as Setting Up Stable Xen DomU with Fedora: Unmodified Fedora 12 on top of Xenified Fedora 12 Dom0 with Xen 4.0 This post only show the difference which
Read more
Creating LVM Volume Group
Posted onHow to create a LVM group from two hard disk partitions is introduced in this post. Assume we have installed two hard disks /dev/sdb and /dev/sdc to the server, our task now is to create one LVM volume group vg_xen for installing LVM backed Xen DomUs from these two disks. We will do this by
Read more
Duplicating and Backing Up LVM Backed Xen DomU from a Remote Server
Posted onLVM’s snapshot feature enables us to duplicate an LVM backed Xen DomU in seconds inside of the same volume group. When we want to duplicate LVM backed Xen DomU from a remote server, we need to make use of LVM’s snapshot function and tools like scp and dd. Backing up the DomU is only part
Read more
Xen DomU’s I/O Performance of LVM and loopback Backed VBDs
Posted onThis posts list benchmark (using bonnie++) result of I/O performance of Xen LVM and loopback backed VBDs. The configuration of machines Dom0 VCPU: 2 (Intel(R) Xeon(R) CPU E5520Â @ 2.27GHz) Memory: 2GB Xen and Linux kernel: Xen 3.4.3 with Xenified 2.6.32.13 kernel DomU VCPU: 2 Memory: 2GB Linux kernel: Fedora (2.6.32.19-163.fc12.x86_64) DomU’s profile: name=”10.0.1.200″ vcps=2
Read more
How to Create Fedora Live USB Media
Posted onHow to create a Fedora live USB media is introduced in this post. We can boot to Fedora operating system environment through a live USB system in the USB flash media on a USB-bootable computer without writing the computer’s hard disk. We can also install Fedora operating system from the live system environment. Remember to
Read more
How to Backup Linux Home Directories Using rsync
Posted onI need to backup my Linux home directory to one of my portable hard disk. I tried to use git, but failed since git doesn’t support large file (I failed after many tries, I have file larger than 5G). I find rsync, the fast, versatile, remote (and local) file-copying tool and I am happy with
Read more
Automatically Backing Up Xen File-backed DomU
Posted onA script for backing up file-backed Xen DomU is introduced in this post. This script can be changed to similar platform. In our cluster, virtual machines are stored under /lhome/xen/. Virtual machine with id vmid is stored in directory vmvmid. The raw image disk file name can also be derived from vmid. Some more details
Read more