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3
votes
1answer
434 views

Does the (source) device in a tmpfs type mount mean anything?

I just went into /etc/fstab (Linux) and changed my line for /tmp (on which a specific ext4 partition was previously mounted) to tmpfs. This was clearly a bit silly, but I wasn't thinking. Anyway, I ...
1
vote
2answers
552 views

Writing data on particular sectors or blocks

Not sure if it's better suited for superuser of serverfault boards, let me know. I have a drive which I repartitioned with fdisk. Initially there was only one big partition, now there are a number ...
3
votes
3answers
782 views

When and why do block devices need to be partitioned? [duplicate]

Possible Duplicate: The merits of a partitionless filesystem So I've got a block device, say /dev/sda or /dev/loop0. Clearly if I want to boot from the former, or I want to subdivide it ...
2
votes
0answers
68 views

xdelta3 fails to decode on block device

I'm trying to use xdelta3 to bring a remote block device into sync with a local one. I'm able to easily generate a xdelta3 patch file using the command: xdelta3 -e -B 33554432 -v -9 -I 0 -s ...
6
votes
1answer
609 views

Run shell script when new volume mounted

I'm interested in running an rsync script whenever any new volume is mounted on my Debian box. What are some potential triggers / strategies for listening for a new volume mount?
4
votes
2answers
2k views

What is /dev/xvde1?

I'm having to do with an OpenShift RHEL Linux installation running on Amazon EC2. In the filesystem, there is a device file named /dev/xvde1 mounted to / ... and a device file named /dev/xvde2 mounted ...
4
votes
2answers
3k views

Where is the GUID Partition Table stored on a device?

A friend of mine used my USB stick to install a new version of OS X on his mac. Now that I got it back, I wanted to wipe it (I use Linux myself). However, I'm having a bit of trouble doing so. The ...
9
votes
1answer
711 views

What driver is behind a certain device file?

Given a device file, say /dev/sdb, is it possible to determine what driver is behind it? Specifically, I want to determine what driver my storage devices are using. fdisk -l lists 2 devices: /dev/sda ...
2
votes
2answers
2k views

Mixing 4k/512 drives with ZFS (FreeNAS)

I have the following drives: Seagate Barracuda ST3200054AS WDC WD20EADS-00S2B0 Samsung HD204UI As far as I understand, the first are ordinary 512 drives while the last is 4096 (Advanced format). ...
6
votes
3answers
3k views

How to read the in-memory (kernel) partition table of /dev/sda?

I accidentally overwrote my /dev/sda partition table with GParted (full story on AskUbuntu). Since I haven't rebooted yet and my filesystem is still perfectly usable, I was told I might be able to ...
5
votes
3answers
1k views

Does /init (or /linuxrc) script creates temporary device nodes in /dev?

Considering that GRUB executes following lines: kernel /vmlinuz root=/dev/sda1 ro initrd /initrd On boot, how does the Linux kernel finds out about /dev/sda1 device node? I know that ...
7
votes
2answers
2k views

Find filesystem of an unmounted partition from a script

I'm writing a custom automated install using AIF (Arch Installation Framework), and I need to find the filesystem on a partition given a partition. So far I have this: grok_partitions () { local ...
2
votes
0answers
472 views

How to check/test internal card reader speed

I got new SD card claimed to be 10 class of speed, but internal Disk utility in linux after test showed up only 6th class of speed. How can I check my card reader speed to be sure that it's not the ...
5
votes
3answers
5k views

Mapping between logical and physical block device names

I cannot figure out the mapping between different logical and physical block device names. The output of "cat /proc/diskstats" is : 104 0 cciss/c0d0 ... 104 1 cciss/c0d0p1 ... 104 2 ...
5
votes
1answer
2k views

Udev rule is not being used?

I'm setting up udev to handle my external USB hard drive when it gets plugged in and removed (no mounting yet). So far, I've made two new rules in /etc/udev/rules.d/10-local.rules to log ...
21
votes
6answers
6k views

How do I correlate /dev/sd devices to the hardware they represent?

A drive is beginning to fail and I only know the device by its /dev/sdb device file designation. What are the ways that I can use to correlate that device file to an actual hardware device to know ...
3
votes
4answers
3k views

From df device name to physical drive name (vendor / type)

Seeing the device name by df, is it somehow possible to resolve it to the physical drive name such as vendor / type. /dev/sda3 915.4G 34.9G 880.0G 4% /share/HDA_DATA /dev/sdd3 ...
4
votes
1answer
222 views

Can unformatted partitions have UUIDs?

Can a partition have a UUID without a filesystem?
2
votes
5answers
1k views

sda and sdb block specials point to same device and get mixed up (hardware RAID doesn't work after new installation of 12.04)

I just installed the latest Ubuntu 12.04 and obviously it screws something up. I'm not sure if this has anything to do with the fact that I have a Raid 1 but at the moment, I have sda and sdb which ...
2
votes
1answer
171 views

Check which network block devices are in use

How can I tell if a /dev/nbd* device is in use? Will "lsof" tell me? Or is there a better way? Is there an equivalent to "losetup -a" which will tell me the next free one?
1
vote
1answer
517 views

Multipath device name doesn't display correctly

I'm playing with iscsi and I'm trying to figure out why the vendor/product names aren't showing up correctly. I've restarted all the appropriate services along with a reboot. Listed below are the ...
1
vote
4answers
10k views

SD card corrupt and stuck at 32MB, any way to fix it?

Using the Linux area since I'm using Linux apps and utilities. My phone crashed (several times) and managed to corrupt my microSD card. It no longer appears to have partitions and shows as 32MB ...
1
vote
1answer
237 views

Bind specific usb out

How can I bind specific usb out to specific /dev/sd* value? Each time that I plugged in some device in specific usb out it binds to different /dev/sd* location. How can I avoid it to set mounting ...
3
votes
4answers
2k views

Comparison of raw block devices

Is there a utility (or some shell magic) that allows me to compare two block devices? Details: I have one large (0.5 TB) RAID device that I've backed up to a slightly larger SATA device using dd. ...
5
votes
1answer
419 views

Unmounting HTC device takes forever

Not sure if should post this on Android SE because I don't think this is directly related to the Android OS. On my system I manually mount and umount my HTC device with these options in /etc/fstab: ...
9
votes
4answers
1k views

Is there a way to sync only one partition?

Is there a way to sync only one partition instead of all partitions? Something like "sync /dev/sdc1".
0
votes
1answer
305 views

block device usage and several mount points

There is some weird thing I don't understand: I have 2G block.img file with an ext4 filesystem inside. There is a 2G test.txt file in block.img. test.txt consists of letters 'a'. Then I mount ...
3
votes
2answers
1k views

Linux Mint: drives' map changing at reboot brings fstab error

I've set up fstab to auto mount media drives on a Linux Mint machine. The OS is installed on a IDE/ATA Disk while 3 SATA disks hold data to share. The BIOS has the ATA disk as first boot device. All ...
3
votes
2answers
1k views

How can I test whether a block device is read-only from /sys or /proc?

On a CentOS6 system I have /dev/block/sr0 (read only) and /dev/block/sda (read/write). How can I find out programmatically which devices are read-only? There is a ro file in there, but it's '0' for ...
2
votes
2answers
885 views

How do I get losetup -a to behave?

# losetup /dev/loop0 /tmp/tmpuUwgbn # losetup -a # losetup -f /dev/loop1 # losetup /dev/loop0 /dev/loop0: [0806]:33654 (/tmp/tmpuUwgbn) # ls -la /tmp/tmpuUwgbn -rw------- 1 root root 0 2011-08-24 ...
12
votes
2answers
1k views

Weight-based block IO control for VMs

I use KVM to manage my virtual machines. I am trying to limit the resources provided for VMs. I am able to limit the CPU and memory allocated for VMs using libvirt/cgroups. Now I want to control the ...
7
votes
3answers
2k views

Mounting multiple img files as single loop device

Is there a way to take a disk img file that is broken up into parts and mount it as a single loop device?
3
votes
2answers
262 views

raid 1/LVM at the level of directories (aka mknodding a directory)

I just experienced data loss, so I am interested in some form of data duplication. I was thinking of mdadm and companions to raid 1 through software. However, I just want a given, not too big ...
2
votes
2answers
285 views

Questions on using command mount

When using command mount for a device, I was wondering about the following questions: Since device file is a parameter to mount, how does one know what the device file for a device is in general? Do ...
5
votes
3answers
2k views

Detecting that a device is mounted to a particular folder?

As part of revamping my backup scheme, I'm now adding rotating external hard drives, keeping one safely off-site at all times while the other is receiving backup data. Naturally, to ensure that my ...
5
votes
1answer
815 views

How to determine if disk is compact flash or standard hard drive

I need to determine in a shell script if a given block device (e.g. /dev/sda) is a compact flash disk or a regular hard drive. Google did not help me out for once, and while udevadm info --query=all ...
3
votes
4answers
1k views

How to get size of a block special file?

I need to be able to determine the size of a block special file. For example, given /dev/sda, I need a command that will provide the size of the device. (By size I mean capacity, since this is a ...
6
votes
3answers
6k views

Prevent a USB external hard drive from sleeping

Does anyone know if there is an elegant way to tell an external usb drive not to spin down after a period of inactivity? I've seen cron based solutions that write a file every minute, but nothing ...
8
votes
2answers
473 views

Prevent disk renumbering on reboot in OSX

I have 3 physical drives in my Mac Pro with OSX 10.6.4. Occasionally after rebooting the machine, the disk numbering changes such that the /dev/disk# does not reference the same drive as it did before ...