A data storage device that supports reading/writing data in fixed-size blocks, sectors, or clusters.

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2
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2answers
43 views

No space left on device on CentOS7

My machine which OS is CentOS7 have to backup 50G data into MySQL. But, there is no space left on the device. But there are many spaces on /home. How can I make user that there are enough space for ...
2
votes
2answers
664 views

KVM linux guest, 2nd HDD, LVM partition or whole disk

I've got a RAID 10 arrays on a couple of KVM host machines. The RAID 10 array is one big VG. I usually create a small LV for guest disk image storage then the rest of the VG I carve out as LVs to add ...
0
votes
2answers
43 views

Can we predict the next registered SCSI mass storage device name

I need to anticipate the device name (sdX) that the next mass storage device (sda, sdb, sdc, …) will receive from the SCSI driver. If I remove one device and connect another one, I noticed that the ...
0
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2answers
261 views

M17: Trying to mount Windows 10 .iso onto partition via terminal, getting “block device ? is write-protected, mounting read-only”. Can I get a help?"

I have Linux Mint 17.1 and am trying to dual boot Windows 10 Technical Preview OR install it on my other hard drive. Extra easy damage-control for you guys- I do not care if I lose any data, as long ...
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2answers
40 views

Cloning a drive larger than your own

I made this nice backup system to turn drives into vdi's and put them on our network share. Then the next day my boss walks in with 20 new machines to replace our old ones, they have 2TB drives. How ...
7
votes
1answer
94 views

Command to generate /dev/disk/-by-path/ name on a system without udev daemon

On most Linux systems udev usually creates symlinks in /dev/disk/by-uuid/ /dev/disk/by-path/ which point to actual device nodes (/dev/sda, /dev/sdb, etc). I don't have udev on my system, and I ...
3
votes
1answer
35 views

Why is the block size of a partition smaller than that of the underlying disk?

My understanding is that the block (in the phrase "block size") is like an IO buffer, or minimum IO size for a device. Since partitions are built on top of physical devices, how can they have blocks ...
3
votes
1answer
223 views

How do I change the OS block size

I am using SUSE 11SP3 and formatted the devices with a block size of 4KB using mkfs.ext3. /sys/block/sda/queue/logical_block_size and /sys/block/sda/queue/physical_block_size show the OS is using 512 ...
1
vote
1answer
35 views

Block device disappears after suspend-resume

After few suspend/resume cycles one of my hdd disappears from the list of devices, here is part of dmesg output that seems to be related to issue: [ 450.005310] sd 5:0:0:0: [sdc] Starting disk [ ...
1
vote
1answer
92 views

How to find the driver (module) associated with SATA device on Linux?

For one of my applications, I have to understand the the SATA device driver flow. As per my understanding, SATA device driver should be there in the Linux kernel tree. I have referred how to find the ...
1
vote
1answer
48 views

DVD giving inconsistent size informatin

I have a (read-only, commercial, dual-layer) DVD which I’m trying to create a backup copy of on my computer (because DVDs can be damaged). However, when I try to determine the size of the disc, I get ...
0
votes
1answer
44 views

How do I detect used harddrive space on a block device?

I want to look at a raw block device (as in /dev/sda) and know how much space is being used on the drive. I don't know what type of file system is on the harddrive, nor do I have any way of figuring ...
3
votes
0answers
62 views

How to cache block devices (for device mapper)?

problem / observed effect It seems that the page cache ignores block devices which are not opened. And worse: Reads from device mapper (DM) devices which use a cached device are not cached at all ...
3
votes
0answers
29 views

Enumerate valid values for mknod

I have access to an embedded device which has a bunch of block/char files under /dev. However, this is not a satisfying description of the hardware, because since the firmware is shared with small ...
3
votes
0answers
291 views

How to change block device names, e.g. /dev/sdc to /dev/sdb?

Example of why this might be desired: I connect a block device, which shows up as /dev/sdb, and mount it. Later that device gets removed without being unmounted. The block device is reconnected, but ...
3
votes
0answers
105 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 ...
3
votes
0answers
764 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 ...
2
votes
0answers
87 views

How to use blktrace to monitor the eMMC Flash access pattern?

I'm trying to simulate a FTL(Flash Translation Layer) algorithm and evaluate its performance. What I need is a trace file of a flash access(containing information about block and page access). I'm ...
2
votes
0answers
136 views

Disk page cache size in Linux for integrity purposes

I am trying to bound corruption in a block-based disk format in the presence of plausible machine failures in a Linux-specific application. That is, the file is read and written in application-defined ...
2
votes
0answers
210 views

Block Devices & Partitions

I partitioned a microSD card (mmcblk1) into two partitions mmcblk1p1 and mmcblk1p2. If use a dedicated card reader I am able to see the entire SD card and its partitions using various disk management ...
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vote
0answers
9 views

Files backing loop devices opened without O_EXCL

Loop devices are the primary way (and perhaps the only way) to treat normal files as block devices in Linux. It's strange that backing files aren't protected by O_EXCL flag. Why is that? Why nobody ...
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vote
0answers
20 views

Tar waiting a long time at end of block device

I had some trouble getting Linux installed to a particular netbook and had to restart it from scratch multiple times. Re-typing the same commands to set up networking and bootstrap the install was ...
1
vote
0answers
36 views

Storage device trouble: IO errors but no bad sectors?

I have a lightly used spinning metal drive (internal) with some VMs on it. I'm running into IO errors while running a VM and upon closer examination I have found a virtual disk file that is reporting ...
1
vote
0answers
12 views

Getting mmc_block to display more than 8 partitions

When you format an SD card or a USB drive with the Chromebook Recovery Utility, it creates twelve partitions. It also leaves the rest of the memory unallocated. I want to be able to use this space as ...
1
vote
0answers
208 views

CentOS 7 - Forcing a disk to be /dev/sda

I've been wrestling with this problem for awhile now, and I've hit a wall and need help. In my system, I have 1 drive connected to a SATA port, an SSD. CentOS 7 is installed to this disk. Also in ...
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0answers
69 views

List partition type GUID's for all disks from command line?

I need to list the partition type GUID's from the command line. Note: This is not the same as the partition UUID. Basically I'm needing to search for all disks that have the Ceph OSD type GUID: ...
1
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0answers
36 views

Remove orphaned rados block device

I'm testing ceph at the moment. Today I decided to start over with my cluster and deleted the old one to setup a new one. I forgot to unmap and delete a mapped rbd device from another host. Now I see ...
1
vote
0answers
394 views

Map a Linux VM's block device to its vmdk file on the vmware datastore

For development and staging purposes, I must frequently create clones of individual virtual harddisks (vmdk container) and move/deploy them into some other system. While I have been able to hack a ...
1
vote
0answers
87 views

GKrellM vs. udev's asynchronous drive mappings on bootup

Well, supposing you had multiple drives (3 in this example), udev would always play dice with them on each system reboot. And now, let's make things a little more quirky by adding one USB flash drive ...
0
votes
0answers
10 views

is `blockdev --flushbufs /dev/mmcblk0p1"` blocking call?

I am using blockdev --flushbufs /dev/mmcblk0p1 in onf the shell script and would like to know if this command doing blocking call or not? I see it from man page that it is ioctl call to the block ...
0
votes
0answers
8 views

How “ata_for_each_link” and “ata_for_each_dev” macros works in linux kernel?

I am trying to understanding the SATA device enumeration sequence from the ata_piix.c Host controller driver which resides at /driver/ata/ata_piix.c in linux kernel. During understanding the flow,a ...
0
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0answers
29 views

RHEL7 : Freeing memory allocated for Block IO i.e. bio -> bio_destructor

I want to know HOW memory allocated for BIO gets free specific to RHEL 7. I think, in RHEL 7 , bio->destructor field is removed from the bio structure. So, how exactly the memory will be freed? ...
0
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0answers
250 views

DRBD device names and numbers

I am trying to deploy a DRBD setup. I am using two virtual machines running CentOS 6.6. It is quite unclear to me how should the drbd configuration file should look like. I am using the following ...
0
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0answers
40 views

one nautilus device went missing, why? and how to fix?

nautilus devices are provided by /usr/lib/gvfs/gvfs-udisks2-volume-monitor, I've already restarted it but one device is still missing. I also tried strace on it, but it only outputs info about mounted ...