Questions about hard disks' performance, issues, tips, and software.

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How to determine disc spindown time

I am able to set both APM and spindown times using the command: hdparm -S 246 -B 128 /dev/sda Unfortunately I can only find the APM value in the information output: hdparm -I /dev/sda | grep ...
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votes
3answers
3k views

When to use Truecrypt, and when not to?

I have about 30 (this number will most likely grow over the next few years to 50 or more) unencrypted laptops that I have been tasked to encrypt (entire drive). These machines will be used off site ...
5
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5answers
654 views

Unix command to suspend a job while there is console activity?

I want to do a large disk transfer, which slows down responsiveness of my system. What I want is a Unix command that will only run the command after I have been idle at the console for a few minutes. ...
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2answers
11k views

What is QSignoff?

The QSignoff folder uses a lot of disk space, can is be pared down without issue?
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2answers
13k views

How do I recover from a faulted zpool where one device is OK, but was temporarily offline?

I have a zpool with 4 2TB USB disks in a raidz config: [root@chef /mnt/Chef]# zpool status farcryz1 pool: farcryz1 state: ONLINE scrub: none requested config: NAME STATE READ ...
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4answers
3k views

Does virtual hard disk fragmentation reported by a guest machine matter?

We have a VM Ware ESXi virtual machine, where the guest is reporting high fragmentation. The host virtual machine file is not fragmented. The datastore is on a RAID 5 array. Does the fragmentation of ...
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4answers
5k views

Which FileSystem is best for CentOS 5 on SSD?

Background: We have gigs of data, which require to process large files simultaneously and in parallel with similar processes. We are going to get SSD just because of fastest latency. We will install ...
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4answers
5k views

How much impact does hard drive cache have on IO performance

How much impact does hard drive cache have on IO performance Are there any statistics or performance tests available that can tell me if there is a difference is 16MB vs 32MB Cache? If it matters, I ...
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2answers
11k views

How can I set the disk partition alignment using linux tools?

After reading Disk Partition Alignment Best Practices for SQL Server, I just want to give those advices a try, but on my linux test server. What are the required parameters in order to set the ...
5
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3answers
210 views

Shared Disk in modern data center (SAN, virtualization, etc)

I'm a developer...treading here on foreign terrain. Please pardon any naivete. I work on an application that stores data both in a database and the filesystem. Context: Clustering and Network ...
5
votes
1answer
502 views

Corrupt files' contents, while FS is OK

Looks like my USB HDD is old and corrupted: rsync: read errors mapping "path/to/file.jpg": Input/output error (5) Syslog: kernel: [58927.940676] sd 6:0:0:0: [sdb] Unhandled sense code kernel: ...
5
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1answer
590 views

Identify which process is responsible for heavy disk i/o under FreeBSD

I wonder how I can monitor which process takes out all my IO bandwith. The only command i know is gstat but it shows cumulative info. Is there any tools i can use to inspect the running processes for ...
5
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2answers
931 views

Managing consistent mounting of external USB hard drives in Linux (CentOS 5)

I have configured a server with CentOS 5.2 and am now working out a backup strategy. I plan on using Amanda as the backup application. Additionally, I am leaning towards using some USB hard drives for ...
5
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2answers
942 views

Linux disable disk cache for a single command

Our server is performing decently, but when backups or other scan processes run it will tank the entire server. Something like clamd will run and scan many files. While we expect slow performance, ...
5
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3answers
260 views

Is visiting the memory of a remote system through network faster than local disk seek?

It seems that network connections are usually faster than local disk seek, as discussed in the question Are networks now faster than disks? I come up with this question when I am using Berkeley DB, ...
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3answers
212 views

Portable, Direct Attached Storage: does such a device exist?

I'm still a fan of tape. I know it's "dying" but for capacity, longevity, and portability, it's pretty tough to beat. However, I have some clients and prospects that have a "hate-on" for tape and ...
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3answers
39k views

centos 100% disk full - How to remove log files, history, etc?

mysqld won't start because disk space is full: 101221 14:06:50 [ERROR] /usr/libexec/mysqld: Error writing file '/var/run/mysqld/mysqld.pid' (Errcode: 28) 101221 14:06:50 [ERROR] Can't start server: ...
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6answers
17k views

How can I tell what filesystems are on a disk in AIX?

I use the tool "topas" to get a quick peek at CPU, memory, and disk statistics on an AIX machine. I understand the numbers on the disk section, but what I don't know is how to tell which ...
5
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1answer
232 views

HDD is acting up, but S.M.A.R.T says everything is fine

Before I begin, a quick disclaimer. I'm basically a developer forced into a sysadmin role by circumstances, so I apologize in advance if I say something stupid or seem like I don't know what I'm ...
5
votes
1answer
284 views

Why are cgroups (blkio serviced bytes) and iotop producing diverging results

I work with lxc user space tools on ubuntu 14.04 and I want to perform some stress tests and benchmarking within a container. I know that free and htop are not working properly in a container. I am ...
5
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1answer
213 views

26 hard drive limit on x86 servers, IBM x3650, Dell PE 2950, Dell PE 2850, where is my limitation?

This is in regard to mass HDD wiping/testing. The software I use, WipeDrive Pro 5 and 7, both fall victim. I originally thought it was a limitation of the software, but after speaking with the ...
5
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2answers
111 views

Is it true that is better to differentiate manufacturers when buying Hard drives for a server?

This morning, listening to Stack Overflow podcast #35 *, talking about Server, RAID controllers and Hard Drives, I heard this thing: if you are going to buy Hard drives for your server, you would ...
5
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1answer
129 views

Getting Error: “No space left on device” for a particular filename

I have a ext4 volume with lot of files inside a particular directory. Whenever I am trying to create a file inside it of a particular name, I am getting "No space left on device" error. $ touch ...
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5answers
3k views

Which hard drive corresponds to ata1.00 and ata12.00?

I have an Ubuntu installation which has a lot of hard drives. Two of these drives have hiccups and SMART is reporting errors. However, I cannot figure out how to determine which drive is ata1.00 and ...
5
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3answers
269 views

Can a VM's virtual disk span over multiple nodes in Ubuntu Enterprise Cloud?

How does storage works with the ubuntu enterprise cloud? If I have two disks (on separate machines) with free space 10gb and 20gb, can I have a VM running with 30gb of disk space?
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2answers
3k views

Mount an ext3 partition with a 16k blocksize?

We are attempting to recover data from a drive which was formated by Netgear ReadyNas Duo. We have dropped it in a linux box and discovered that it is formated as ext3 with a 16k block size. Mounting ...
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3answers
1k views

How do I calculate the disk subsystem i/o capacity

I am trying to figure out the number of 8K page i/o capacity for a disk subsystem. The drives are SATA 7200 RPM - 4 drives in a RAID-5 configuration. I am not sure about the SCSI controller but the ...
5
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1answer
4k views

Change owner of LVM LV's device node in RHEL5

First time using serverfault, please excuse any breaches of etiquette. I've created several LVM2 logical volumes in local storage on a server, and would like one of the device nodes - not the ...
5
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2answers
4k views

Issues with Server 2012 using DFSR running on Hyper-V 2012

We have a number of Server 2012 systems, all of which run virtualised on Hyper-V 2012 server. We are having problems with two such virtual instances, both of which are used as file servers, whereby ...
5
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2answers
2k views

e2fsck extremely slow, although enough memory exists

I've got this external USB-Disk: kaefert@blechmobil:~$ lsusb -s 2:3 Bus 002 Device 003: ID 0bc2:3320 Seagate RSS LLC As can be seen in this dmesg output, there is some problem that prevents that ...
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2answers
1k views

Disk (EXT4) suddenly empty without any sign of why

I have a Ubuntu 10.04 server with several disks in it. The disks are setup with a union filesystem, which presents them all as one logical /home. A few days ago, one of the disks appears to have ...
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2answers
1k views

HP 4TB SATA Midline in D2600 - what disk make is HP using & why WD RE4 don't work?

Does anyone know what make of disk HP are using in their 4TB SATA Midline & why WD RE4 don't work? So we use D2600 crates with HP 2TB disks, and just buy WD2003FYYS - pop them in old HP caddies. ...
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5answers
2k views

What options are available to perform whole disk encryption with Snow Leopard

We would like to encrypt the entire disk of a Snow Leopard workstation running some sensitive file, database and web services. PGP does not yet work for 10.6, and we cannot use FileVault as it is not ...
4
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7answers
1k views

Tips and tricks for identifying the dying hard drive

I have a raid 1 that has failed partially. The controller tells me the raid is degraded, but does not tell me which drive is failing. When I look in My Computer, I see that the controller split my ...
4
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7answers
763 views

Inexpensive degaussers or HDD shredders?

Apologies, I'll simplify my question: Are there any degaussers or HDD shredders out there in the $500-1500 range designed for use as such that you would recommend for low-volume use?
4
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6answers
851 views

What are the the potential drawbacks of using non-OEM hard drives in a server?

I'm currently speccing a Hyper-V host for my company and would like to use solid state drives for local storage. The problem is, most oem drives have a hefty premium when compared to retail ...
4
votes
3answers
2k views

Why do servers have SAS instead of SSDs? [closed]

I was wondering why do servers still come with SAS disks instead of SSD disks? I know that SAS are faster than normal hard drives but they are still much slower than SSDs. I think they are more ...
4
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6answers
24k views

How can I convert a logical partition to a primary partition?

I had my primary partitions maxed out but I deleted some and now I want to make one of my logical partitions a primary. Can I do this with gparted or other free tools? Thanks
4
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2answers
833 views

Web site kills hard disk I/O, how to prevent?

The situation: I have a server, on which we have 2-3 projects. Starting not long ago, the server started hanging up (We could not connect to it by ssh, and the connected clients had to wait 20 minutes ...
4
votes
3answers
695 views

RAID - buy spare disks at same time as originals?

When using RAID1, is it best practice to buy spare disks at the same time as the original disks to ensure you have the identical type in case they become unavailable in future?
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6answers
1k views

Securing a single HDD from a retired RAID 5 array

I want to sell two hard drives. Both have been used in a software RAID5 with a logical volume manager. I want to delete all data in order to sell them. But on the devices are no partitions. Is it ...
4
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5answers
839 views

Hard drive throttling?

You're copying a lot of stuff in same time and computer performance just dies. Try for example to copy 10+ ISO images same time. There's QoS in networking, affinities and priorities in CPUs, but is ...
4
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4answers
268 views

Is it safe to mark a disk ok, in a degraded raid 5 array?

Intel Matrix Storage Console 8.9 showed a degraded array with one disk failure. Yet it offers the option to mark the disk as ok and rebuild the array? When would it be appropriate to do this? Does it ...
4
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4answers
336 views

What is the best hard drive for random-reading small blocks

We need to do random reads (seeks) on 5 KB blocks from a huge file (150 gigabyte). What hard drive is the best suited for this type? What is the expected performance from an SSD in this scenario? I ...
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8answers
956 views

Getting data out of a non-working SATA drive

Can anything be done to get data out of a dead SATA drive, the drive won't even show up on the list of drives when booting the computer? UPDATE: The drive was never backed-up. It was an external ...
4
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6answers
504 views

Is there a Linux utility that can distribute files to an array of hard disks, like a load balancer, but for storage?

I have 2 1TB disks not in any RAID configuration. I'd like files I need to store to be placed on one of the disks depending on the capacity of the disks, and when accessing the file I suppose I'd need ...
4
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4answers
537 views

I have a 3.46 TB Raid disk array, but when I setup windows server 2012, it only refers to it as 2TB

I have a 3.46 tb raid disk array, but in volumes it shows it only as 2.00TB What have I done wrong, and how can I fix it? Thanks Noam
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3answers
1k views

mdadm RAID 5 Failed with 2 Drives while rebuilding

I have a RAID 5 array with 3 Disks (sdb sdc sdd) Over last weekend I was prompted that sdd had failed. so replaced the drive, added it back into the array and let it rebuild (1.5TB) It stopped at ...
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4answers
5k views

Are new HP Gen8 servers compatible with g7 drives?

Are HP Gen8 servers (namely DL380 Gen8 with 2.5" HP disks) compatible with 2.5" harddrives from G5-G7 servers? I mean original HP disks in HP caddies not plain SAS/SATA drives.
4
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4answers
967 views

Disk full on linux server, blocks used is much less then blocks avalable

Output of df is: [root@backup log]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/VolGro 1889811408 1861658948 0 100% / /dev/sda1 101086 ...