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4
votes
2answers
178 views

Can you identify transport via sysfs?

I'm writing a script, and I'm interested in being able to identify the transport class (fc - "fibre channel", scsi, iscsi, etc.) for a given block device. I can retrieve this information via ls -l ...
2
votes
1answer
2k views

Linux EMC scan Lun not working

We have CX4-120 EMC SAN storage, I expend existing LUN size to 20GB but now i am not able to see any cylinder changes on host fdisk -l output. Following command i am running to re-scan my hda or LUN ...
1
vote
2answers
147 views

mknod of content in directory

I would like to create a virtual device from a directory i.e. you know, there's these cloud storage providers like dropbox and co and they generally have a software client and then give you access to ...
5
votes
1answer
2k views

Is it possible to change the sector size of a partition for zfs raidz pool in linux?

I've been migrating a zfs raidz pool on linux to new discs via virtual devices which were sparse files. I've used partitions on the discs as the discs are different sizes of 1.9T each. The last disc ...
0
votes
2answers
480 views

Should I change SSD?

Demsg shows this EXT4-fs error (device sda1): ext4_ext_get_blocks: inode #7743113: (comm flush-8:0) bad extent address iblock: 3503, depth: 1 pblock 0 EXT4-fs (sda1): delayed block allocation failed ...
0
votes
0answers
83 views

Redundant and Load Balanced storage on FreeBSD?

Back from: Load balanced & Redundant Storage on FreeBSD How do I create a (Redundant and Load Balanced) Storage based on FreeBSD? Storage should be located on (2 or more servers) providing ...
2
votes
2answers
109 views

What is a good way of layering zfs filsystems to manage unpredictable future workload that doesn't severely compromise performance?

I've been playing around with ZFS and using sparse files as virtual devices to learn how to use the zfs tools. It seems that there isn't much of a hit in performance by creating a raid pool out of ...
1
vote
1answer
766 views

-bash: /usr/sbin/useradd: Input/output error — What does this mean?

Today, on my Centos server I tried to add a user but got the following error: -bash: /usr/sbin/useradd: Input/output error How do I fix it?
1
vote
1answer
284 views

can linux be configured to blink an LED (GPIO) on disk activity?

I'm hoping to blink an LED that is wired up to a GPIO line whenever the USB connected disk has activity is there an easy way to pull this off?
2
votes
0answers
223 views

Move boot disk on SAN storage on Solaris 10

I'm looking for some infos/official docs/howto for migrating boot disks in a production enviroment server from internal disks to SAN on Solaris 10. It's possible for every kind of hw? It's also ...
3
votes
1answer
477 views

What are potential consequences of going nuts with sparse file based vdevs for a LVM to ZFS migration?

I've been playing around with ZFS having finally accepted that it's mature enough I shouldn't get burned. Now to migrate the home NAS box which is currently an LVM JBOD set up that's quite full, but ...
1
vote
1answer
230 views

Can we create lvm volume group with mapped device?

I can create a lvm volume group with a loop device. But if I use dmsetup to map the loop device into several devices, then I can't create a lvm group with /dev/dm-. Why is it not possible to create ...
0
votes
1answer
2k views

How to open OLE2 Compound Document Storage database?

I have file called Thumbs.db that I seem unable to open with anything. SQLite Database Browser can't do it, nor can LibreOffice Base. Opening up the file properties tells me it's an 'OLE2 Compound ...
3
votes
2answers
1k views

Load balanced & Redundant Storage on FreeBSD [closed]

Did Google for this the last week, still can't find any reasonable solutions for FreeBSD. Most of the articles contain solutions for a fail-over storage only (FreeBSD HAST). This is NOT what I'm ...
2
votes
2answers
910 views

How can I mount vxfs FS to two or more Solaris servers?

I want to have two Solaris servers share the same SAN vxfs Filesystem. Though at a time just one would be accessing the share. This is to allow for a quick failover in case the primary server ...
2
votes
1answer
5k views

What to do after the LUNS are created

Our Management bought a New EMC2 VNX storage device . And a guy from vendor came to create the LUNS. I honestly have no idea how to configure the EMC SANS as i never got a chance to work on such ...
1
vote
2answers
481 views

How can I check how much space I am allowed to use on a linux server?

I have some giant files I'd like to back up by putting them on a server I am allowed to use for such things. However, I am uncertain about how much space I am allowed to use. Is there any way of ...
5
votes
2answers
675 views

How do I refresh the magnetic state on a disks with backups?

I have a couple of large disks with backup/archive material on them. They're ext4. Regarding the ones of those that will be stored for a couple of years without reading the whole disc again I've been ...
13
votes
1answer
3k views

How do pdflush, kjournald, swapd, etc interoperate?

Recently saw a question that sparked this thought. Couldn't really find an answer here or via the Google machine. Basically, I'm interested in knowing how the kernel I/O architecture is layered. For ...
7
votes
3answers
5k views

What is the best practice for adding disks in LVM

According to the Linux manpages you can add raw disks as well as partitions to a volume group. In other documentation (RedHat, CentOS or openSUSE), all examples refer to adding partitions to the VG ...
2
votes
1answer
8k views

extending a partition by resize2fs

I have a 4 GB SD card. Before the image load root@ubuntu# fdisk -l Disk /dev/sdb: 3965 MB, 3965190144 bytes 49 heads, 48 sectors/track, 3292 cylinders, total 7744512 sectors Units = sectors of 1 * ...
0
votes
0answers
154 views

Custom Bluetooth Configuration through terminal

I am running a Bluetooth module on my circuit for transmitting data. I want to connect this module to my Linux OS (openSUSE) and read data from it. I want to do custom configs and also custom read ...
1
vote
1answer
496 views

Can you mount UFS partitions made in Solaris (Sparc) on Solaris (x86)?

I am reading about Endianness and it seems both systems save their data differently. Sparc uses big endian and x86 uses small endian, meaning the byte order is different. That makes me wonder... is ...
0
votes
1answer
181 views

Arch installation and swap partition

to install Arch on a PC I have to make partition of the HDD boot swap / The swap is used by virtual memory, right? What's up if I make a too small or a too big swap partition? Could I have as ...
1
vote
1answer
556 views

File access after fsck very slow for first-time access?

My drive started to show up errors, I unmounted it and ran fsck on it. It's a 2TB drive installed on Debian Squeeze, using ext3. The fsck too about 17 hours. I found some, luckily mostly unimportant, ...
2
votes
1answer
265 views

Alix Board write performance

I have an alix board on which I have installed debian4alix (sqeeze). After using it for a while I noticed that the write performance of the board was pretty low. I ran the following test: dd ...
1
vote
0answers
167 views

iSCSI on startup

I've configure iSCSI but CentOS 6.3 is unable to recognize if on startup. Here is fstab config: /dev/sdb1 /home ext4 _netdev 0 0 Here is iscsi.conf ...
8
votes
1answer
214 views

How to re-size partitions in a complete hard drive image?

I have taken a complete image of a hard drive using: dd if=/dev/sda of=/home/user/harddriveimg bs=4M It would seem to me, that I should be able to re-size the partitions within it after suitably ...
1
vote
1answer
83 views

Does a return from a shell command guarantee that output files have been written?

I'm building an OSX app and use the screencapture command to grab a screenshot and write it to disk: screencapture -mT0 ~/screenshot.png Can I, if I'm not running a UNIX commands in the background, ...
0
votes
0answers
217 views

Can't format SSD during installation

Last night I tried to install Mandriva Linux on PC, where I have already Windows 7. In PC I've got 2 128GB SSD and 1 2TB HDD. On one SSD I installed Win7, and when I select the other empty SSD for ...
1
vote
2answers
675 views

luxadm disp equivalent for Red Hat?

Is there an equivalent to: luxadm disp *disk* for Red Hat? I need to check that all the device address to the SAN are ONLINE for a certain disk.
5
votes
7answers
26k views

Finding all storage devices attached to a Linux machine

I have a need to find all of the writable storage devices attached to a given machine, whether or not they are mounted. The dopey way to do this would be to try every entry in /dev that corresponds ...
1
vote
1answer
2k views

EMC storage + powercf command + powerpath

When I run powercf -q on my Solaris machine, what changes does this command do on the EMC storage, or on Solaris file system? From manual page: DESCRIPTION During system boot on Solaris hosts, ...
2
votes
2answers
185 views

How to securely export a device (HDD)?

So I have a Scientific Linux 6.3 (RHEL clone so basically the question is Redhat related) machine called "B" (with an extra "A" HDD besides the system HDD) and a notebook with SL 6.3. They are in a ...
3
votes
1answer
724 views

Trapping “READ FPDMA QUEUED”

Recently I encountered a kernel message: ata3.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 ata3.00: irq_stat 0x40000008 ata3.00: failed command: READ FPDMA QUEUED ata3.00: cmd ...
10
votes
1answer
3k views

Defragmentation of LVM2 logical volumes

Question: Is there a tool supporting de-fragmentation of LVM2 logical volumes ? (Making their extents into consistent sequences) Preferably by defining desired order of extents (something like ...
10
votes
1answer
7k views

Understand output of `udevadm info -a -n /dev/sdb`

I plug an external HDD into my laptop. I try to find out the information by $ udevadm info -a -n /dev/sdb Udevadm info starts with the device specified by the devpath and then walks up the chain of ...
3
votes
1answer
3k views

Clear unused space with zeros (btrfs)

How to clear unused space with zeros ? (I am asking for tool for btrfs filesystem) I'm looking for something smarter than cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero Like ...
1
vote
1answer
367 views

Do I need ephemeral storage?

I was running a small instance on Amazon EC2. I'm trying to migrate it to a micro as it requires very minimal processing power. One thing I just learned though, is that micro instances do not come ...
22
votes
4answers
18k views

Clear unused space with zeros (ext3,ext4)

How to clear unused space with zeros ? (ext3,ext4) I'm looking for something smarter than cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero Like FSArchiver is looking for "used space" ...
5
votes
3answers
2k views

Resume interrupted copying process

How to resume securely and reliably process of copying file $A into backup location $B done with pv "$A" > "$B" or cat "$A" > "$B" ? (let's assume file $A is very big, e.g. LVM2 snapshot file) ...
2
votes
0answers
60 views

Limiting write rate of a device

How does one go about limiting the write/read rate of a device, E.G., USB drive, SD card? Motivation behind this question is covered here (superuser.com).
2
votes
0answers
219 views

How do create an encrypted system with multiple Linux distributions?

A few weeks ago I created a completely encrypted system on a notebook and must say I like the idea. It's a little bit annoying to enter the password on every boot, but it's nice to know even if I ...
0
votes
1answer
67 views

Will SGE output slow down my simulation, if so, how much?

I am using clusters at my university's high performance computing center, they are using SGE system to do the job management. You might know that by default the SGE will output two files: NAME.oXXXXX, ...
1
vote
0answers
176 views

Getting from proficient to expert [closed]

I've got my vacation coming in and thought I might use that for something useful. Essentially, I've been a Linux user since around 1995 when I installed Slackware 2.0 on my computer and have been ...
1
vote
1answer
2k views

Where can I find storage integrity (write/read) test tools?

I am in need of tools to verify data integrity of local harddrives, usb-drives, etc. I am looking for a solution like the famous www.heise.de/download/h2testw or something that is at least common ...
8
votes
1answer
4k views

How can I check the condition of an SD card?

How can I check the health condition of an SD card? When I want to check a hard drive, I can use SMART, how should I check an SD card? Is there a universal approach?
2
votes
1answer
207 views

What is the smallest LVM2 logical volume unit?

Could you ensure me that minimal LVM2 size Unit is one extent to which all sizes are rounded up ? Is 4MiB the default size of extent for LVM2 ? Can it be configurable or is it the only size ? Small ...
6
votes
2answers
2k views

How to properly unplug/plug removable LVM2 device?

How to properly unplug (remove) and later plug (insert) removable (hot-plug, usb etc) storage device with LVM2 on it ? I've found this note Remove (unplug, eject): lvchange -an ...
6
votes
1answer
2k views

Move qcow2 image to physical hard drive

I have a qcow2 image that I use to boot an installation of linux using QEMU; I would like to place the contents of that image directly onto a physical hard drive so that I can boot to that linux ...