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0
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1answer
211 views

Where does bash store the time commands were executed?

Enabling history to display time via export HISTTIMEFORMAT='%F %T ' shows the times of the commands but .bash_history doesn't contain any times. Where does bash store the times the commands were ...
5
votes
1answer
352 views

Can I make a USB port on my Linux computer look like a mass storage device?

I'm running Kubuntu 12.04 on my PC. I want to make one USB port on my computer appear as if it is a USB mass storage device to other devices. In other words, something connected to this USB port will ...
0
votes
2answers
291 views

Does configuring iscsi target and iscsi initiator in two linux nodes and using ethernet cable for communication make it SAN?

I'm using freeNAS to share an extent via iSCSI to my another Linux box using Ethernet cable. It work as a block storage. So SAN work as a block storage. Now, in my scenario is it working as a NAS or ...
3
votes
1answer
182 views

rsync move files, leave directories?

I'm using rsync to copy data between my internal and external hard drives. It's done what I need, but I'm running out of room on my internal hard drive. So, is there any way to get rsync to function ...
0
votes
3answers
690 views

Software RAID 1 with dissimilar size and performance drives

Background I was experimenting with a home server setup in a small box I had that was supposed to be a media centre but never found much use. I installed CentOS 6.5 in a software RAID1 configuration ...
3
votes
2answers
160 views

Does using full-disk encryption affect the probability of losing data in case of storage errors?

So.. if there is a bad block on the HDD, what can survive better? not using FDE (full disc encryption) using FDE - since the whole disk has "1 partition" - the encrypted one, isn't it more likely to ...
2
votes
0answers
61 views

Too large cache causes disks to grind, I/O to drop

This is a followup question to my earlier problem. In short I was experiencing massive I/O drops together with not-so-violent disk grinding, and with help I found out that the big caches were the ...
3
votes
3answers
589 views

How to migrate data from server to server with as little downtime as possible?

I have a server running dovecot using the maildir format with a fairly large userbase (10k users or so) with each user having around a GB quota. The actual mail directories are stored on a separate ...
3
votes
1answer
470 views

How does ZFS grow/scale?

I am wondering how would one design a ZFS system to build something that is massively scalable, along the lines of your favorite cloud storage, but with all the neat benefits the come with ZFS. A ...
1
vote
0answers
141 views

Mount an SD card over USB?

I'm currently using: insmod g_file_storage.ko file=/dev/mmcblk0p1 stall=0 removable=1 This works as I can see the device in Windows. However when it comes to changing a file, the changes are not ...
4
votes
2answers
207 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
153 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
540 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
84 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
112 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 ...
2
votes
1answer
854 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
303 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
235 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
531 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
242 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
1k 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
6k 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
554 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
771 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 ...
9
votes
3answers
7k 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
163 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
531 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
195 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
581 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
269 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
169 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
219 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
225 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
733 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.
6
votes
7answers
32k 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
195 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
815 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 ...
11
votes
1answer
4k 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
8k 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
371 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 ...
23
votes
4answers
21k 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" ...