Questions about disk drives under the UNIX and Linux systems. See also the "filesystems" tag.

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AIX equivalent of Solaris' iostat -E

On Solaris you can use the command iostat -En to view "disk error statistics" as counted by the kernel since the last reboot, where the -n option causes iostat to show "nice" device names. I'm ...
0
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0answers
32 views

Calculate Total disk i/o by a single process [duplicate]

I am looking for some tool that will dump total disk I/O by a single process after it ends. So far my finding is :- iotop= It shows i/o per process in real time but does not give total after process ...
0
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1answer
55 views

What do these errors mean in sysbench disk test?

I have been running a continuous test of sysbench disk tests on my Linux system that uses compact flash. I am seeing some errors in the output, as shown below. What do these errors mean exactly? Do ...
2
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0answers
83 views

The proper way to turn off an external sata encolsure?

I have an e-sata external enclosure with a port expander and 4 sata disks in it that I use for periodic backups. I have what I think is a sound method for powering it off, but not sure if it is the ...
92
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26answers
11k views

Tracking down where disk space has gone on Linux?

When administering Linux systems I often find myself struggling to track down the culprit after a partition goes full. I normally use du / | sort -nr but on a large filesystem this takes a long time ...
6
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2answers
69 views

FreeBSD 10 trace disk activity

Is there any way to find some process which is periodically writing to disk (according to hdd led) on FreeBSD 10 with ZFS (maybe turn ZFS into verbose logging mode)? lsof and other instantly ...
0
votes
1answer
170 views

How to mount the `D:\` disk of Windows in linux mint? [closed]

I am unable to mount the D:\ disk of windows in linux mint. What to do?
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0answers
14 views

SMART extended offline test validity

Is it possible for the smartctl -t long /dev/sda to complete without error and still the drive fail? How detrimental to the disk's life expectancy is running the test daily/weekly? Thanks!
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0answers
26 views

Disk copying with two OS on it

I want to change HDD in my laptop to bigger one. I have installed WIN XP and Mageia Linux and GRUB ver 1 as bootloader. So I want to use such procedure for copying and changing disk: plug new one ...
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0answers
51 views

Monitoring Disk Latency

We have quite a few physical machines in our environment, yet we have no trending data over a period of time for disk latency statistics. We can easily run the standard iostat commands to see what the ...
1
vote
1answer
117 views

CentOS 5 - hdparm - how to set DMA mode

I'm running CentOS 5 with a PATA hard drive. I've used hdparm to tune the hard disk for better performance, but there are 2 settings that don't work: hdparm -M 254 /dev/hda gives the error ...
3
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4answers
351 views

How can I zero files out inside a VMware image file so that their space can be reclaimed?

is there a command on Linux to remove a file but zeroing it's contents first? so if i do, something like this: rm -rf /var/cache/pacman/pkg/* it would overwrite each file on that directory with 0 ...
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0answers
48 views

expanding boot, moving LUKS root

GPT > Partition2 > LUKS > btrfs I need some additional space for my boot volume, so far I did: Shrink my btrfs volume by 250MB. btrfs resize -250M / Shrink the LUKS root volume cryptsetup ...
1
vote
1answer
133 views

Stat disk drives wihout lsblk?

I have a minimalist busybox system that I was recently trying to use, and I found a small problem: it has no lsblk command. Is there another command to list disks, partitions, and sizes like lsblk? ...
2
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0answers
23 views

midnight commander: rules for accessing archives through VFS

Midnight Commander uses virtual filesystem (VFS) for displying files, such as contents of a .tar.gz archive, or of .iso image. This is configured in mc.ext with rules such as this one (Open is Enter, ...
2
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3answers
211 views

Any programs suitable for making a database over disk-content?

I have quite a lot of external hard-drives, and often have a hard time finding what I'm looking for - not to mention not storing the same file several times on different drives or finding free space ...
1
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0answers
26 views

Edit partition of disk part of a ZFS Raid

I've gota strange problem. Since a previous failure from one of my hard drive, I had to replace one of my 4 hdd running in RAIDZ. But since I changed this disk, the last partition of my disk appear ...
1
vote
1answer
80 views

Problem creating raw disk image and mounting it in rescue mode to QEMU

I am trying to create booting system from raw disk image. This is what I do: $ dd if=/dev/zero of=system2.img bs=1M count=6000 6000+0 records in 6000+0 records out 6291456000 bytes (6.3 GB) copied, ...
1
vote
1answer
55 views

How to find the true disk usage on my Linux box?

I have a linux box on my school's server. When I was trying to install Protocol Buffers, disk usage is reported as exceeded. So I checked my disk usage by two command on my home directory: du -h ...
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0answers
14 views

Install system to Disk on Chip

I'm looking for an easy way to install linux on a PC104 (x86 no cmov) system with a Disk-on-Chip. It can be a very simple system (BusyBox, etc) or a distro the installs in under 512mb. I just need to ...
1
vote
0answers
4 views

Unable to open Windows Disk partitions in solaris 11 [duplicate]

I have recently installed solaris 11, but I am an absolute beginner in unix systems. The only unix like environment I have got myself into before is ubuntu which was quite a bit different from solaris ...
3
votes
1answer
1k views

Expanding the disk size on pfsense under VMWare ESXi

I've been testing pfsense on ESXi for a while. And now I'm almost running out of space. Currently it holds around 30GB and I would like to expand it to 150GB as I'm planning on installing squid for ...
1
vote
2answers
91 views

start qemu by giving it a path to a linux root

Good evening, I installed ArchLinux on a USB stick, and I would like to boot it in qemu. Unfortunately, most examples I found boot an image (iso..). The stick is definitely bootable as if I restart ...
36
votes
7answers
51k views

How can I monitor disk io?

I'd like to do some general disk io monitoring on a debian linux server. What are the tools I should know about that monitor disk io so I can see if a disk's performance is maxed out or spikes at ...
4
votes
2answers
453 views

How does Linux md-RAID handle disk read errors?

There are 2 cases: the read command times out at kernel level (30 seconds by default), the drive reports its unability to read a given sector before the kernel lose patience (the case I'm ...
1
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2answers
163 views

Disk on key is read only on every computer

I have a 16 GB SanDisk Cruzer Blade Disk-on-key. After a few days of use, it has become write-protected/read-only. When I plug it in, you can see this in my Ubuntu's dmesg: [ 819.003359] usb 2-5: ...
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8answers
6k views

How to determine which sd* is usb? [duplicate]

Possible Duplicate: How to know if /dev/sdX is a connected USB or HDD? The output of ls /dev/sd* on my system is - sda sda1 sda2 sda3 sda4 sda5 sda6 sda7 sdb sdc sdc1 sdc2 ...
2
votes
3answers
223 views

/dev/disk/by-uuid/ not working on one machine

I have a iSCSI disk which I am mounting from several machines (exclusively, not concurrently). On machine A, I start iscsi service open-iscsi start and the iscsi disk is discovered as /dev/sdb1. ...
0
votes
2answers
174 views

How to get total disk read/write in bytes per hdd device from /proc

How to get total disk read/write in bytes per hdd device? for example if i have sda, sdb, and sdc, is there any file on /proc that i could use similar to /proc/net/dev for networking?
2
votes
1answer
186 views

libata patch to allow disable sata port

My question is related to the patch introduced in this post How to tell Linux Kernel > 3.0 to completely ignore a failing disk? If the kernel is patched with this code what is the kernel parameter ...
-1
votes
1answer
52 views

What is a file? [closed]

I thought that the file is a reserved place on disk and it is a Record collection but i found that it is a wrong definition because the empty file capacity is 0kb so it can't be a reserved place on ...
3
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0answers
94 views

Unable to close a Luks partition

For backup purposes, I have "snapshotted" a LVM partition. This partition was crypted so I have opened this Luks partition (snapshot) in order to do my backup. The problem is that I have forgotten to ...
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3answers
1k views

How to get total number of bytes/sectors/blocks written to disk since booting?

I'm considering and update from HDD to SSD. But since Flash cells can only sustain limited writes. I want to know how much data my computer write during normal operation. So I can determine how long ...
6
votes
4answers
1k views

Given a kernel ATA exception, how to determine which physical disk is affected?

I woke up this morning to a notification email with some rather disturbing system log entries. Dec 2 04:27:01 yeono kernel: [459438.816058] ata2.00: exception Emask 0x0 SAct 0xf SErr 0x0 action 0x6 ...
4
votes
1answer
245 views

Edit file on image created with dd [duplicate]

I've a bootable USB with Debian. Normally I clone the disk with dd, write the image on a new USB disk, mount this disk on my filesystem and edit some files. Is it possible to edit files on the image ...
0
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1answer
58 views

Why I got a strange result for fdisk -l

root@host [~]# fdisk -l Disk /dev/sdc: 128.0 GB, 128035676160 bytes 255 heads, 63 sectors/track, 15566 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 ...
2
votes
4answers
510 views

What is the /dev/disk/by-uuid/ and why does it use all free space on the disk

I have the following Debian that works in Virtual Box: $ uname -a Linux debian 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 x86_64 GNU/Linux Recently I notice that I don't have any free space: $ df ...
5
votes
2answers
270 views

How to create a fixed size Linux ramdisk which does never swap to disk?

I want to create a fixed size Linux ramdisk which never swaps to disk. Note that my question is not "why" I want to do this (let say, for example, that it's for an educative purpose or for research): ...
0
votes
1answer
73 views

Is there something wrong with df output? [duplicate]

I'm using the command df -h to check disk usage on CentOS 6.4. I see an inconsistency with the output. look at the line Filesystem: total 490Gb, used 55Gb, and Available 411Gb. What is it mean? I ...
4
votes
1answer
7k views

/dev/sdb: No such file or directory (but /dev/sdb1 etc. exist)

I'm not sure what is wrong here but when running fdisk -l I don't get an output, and when running fdisk /dev/sdb # I get this fdisk: unable to open /dev/sdb: No such file or directory I'm ...
2
votes
1answer
341 views

Mounting another VM's .vdi in VirtualBox

I have two VMs in VirtualBox. For exmaple, VM 1 runs Red Hat, and VM 2 runs Ubuntu. For the Red Hat VM I have redhat.vdi and redhat2.vdi, and for the Ubuntu VM I have ubuntu.vdi and unbuntu2.vdi. ...
3
votes
2answers
51 views

Uniquely identifying a drive (not a partition)

I'm writing some automation scripts for full disk backups and I'd like to be fairly precise with which devices are used. I know that one can uniquely identify a partition using UUIDs and blkid, but ...
2
votes
2answers
207 views

How do I navigate to a CD drive?

I'm trying to install Virtualbox Guest Additions in Elementary OS. cd doesn't seem to work with cd VBOXADDITIONS_4.2.6_82870. Update: I did what @ivica recommended, and here's what I'm getting: I ...
0
votes
1answer
57 views

How to create memory-based disk in linux? [duplicate]

I need to have a very fast disk for keeping cache. How can I do that in Linux?
2
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1answer
232 views

Difference between “blockdev --flushbufs” and “sync” on Linux?

Is there a difference in practice between running blockdev --flushbufs and sync(1) on Linux? (apart from blockdev flushing for a specific device, and sync being system-wide). sync(1) manpage says it ...
2
votes
2answers
539 views

Free space: 0 bytes and files full of data shown as empty

I don't know what's going on. The last evening I left my computer with about 700MB of free space on the system partition and today there is no free space on disk, moreover a lot of files containing ...
1
vote
1answer
67 views

Repartion multiple disks and reallocate storage

I’m trying to re-partition from an Arch Linux install disc. I’m doing so because my current OS is corrupted. When running fdisk –l this is what it looks like: /dev/sda1 * start=2048 end=1026047 ...
3
votes
2answers
1k views

How to Add Extra Disks on KVM based VM

I installed Redhat 6.4 on KVM Server. Right Now there is only One Disk /dev/vda. Now I need to add extra Disk like /dev/vdb I tried adding New Volume but it is not showing when I do fdisk -l How to ...
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0answers
141 views

How different is I/O handling of hard disk in AIX and Redhat Linux?

I am running a hadoop I/O workload in redhat linux and have ran that in IBM AIX as well with same underlying hardware, disk and disk configuration. With the default settings on the os redhat linux is ...
6
votes
2answers
370 views

Creating formatted partition from nothing

I need to create filesystem with just one partition from nothing (/dev/zero). I tried this sequence of commands: dd if=/dev/zero of=mountedImage.img bs=512 count=131072 fdisk mountedImage.img n ...