Primarily questions about disk storage, sometimes questions about application storage or cloud storage. Always questions about storing data.

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8
votes
2answers
30k views

Fibre Channel LUN rescan and QLogic

I have a serious problem with a SAN storage array connected to a Linux box through Fibre Channel. Here is the configuration : Debian with plain vanilla linux 2.6.27.25 Fibre controller QLogic 4Gb ...
7
votes
6answers
3k views

hardware recommendations for a DIY storage system based on ZFS [closed]

Looking to make use of old server lying idle as a proof-of-concept ...here are specs Dell PE 2900: Xeon 5110 - 2P, 12 GB RAM, 8x 300 GB 15K drives, Perc 5i+256 MB cache what additional h/w would be ...
7
votes
16answers
6k views

Cheap but Highly Available Shared Storage? [closed]

my group is in the market for plentiful storage. We traditionally used big-iron FC-attached SANs, but they are way expensive and provide much more performance than we require. We want highly ...
7
votes
6answers
1k views

solution to store 10TB /Month

I'm working at a small TV company. They generates 11TB of video files per month. What can I do?. I just need ordinary SATA disks, in RAID. What solution should I buy? (They are using a lot of ...
7
votes
4answers
14k views

What is the difference between LVM and LUN

Both seem to be a virtualization layer on top of physical disks. I'm having a hard-time understanding each of them and the difference between them.
7
votes
3answers
716 views

What is the use-case for NAS on a mid-to-high end storage array?

Many large storage vendors (EMC, NetApp, etc) provide storage equipment that does NAS in addition to FCP, FCoE, or iSCSI. When would it be appropriate to use the NAS functionality of these boxes? In ...
7
votes
6answers
3k views

Truecrypt: File vs Device hosted encryption

TrueCrypt allows the user to create an encryption volume on a file or a device hosted encryption on a drive or partition.What is advantage or disadvantage of one over the other?
7
votes
4answers
234 views

Does orientation during storage affect CD-ROM or DVD lifespans?

Related: Does orientation affect hard drive lifespan? I have been told that optical media must be placed in the horizontal position during storage, the theory being that gravity can affect the ...
7
votes
5answers
666 views

How should we serve files in a small bioinformatics cluster?

We have a small cluster of six ubuntu servers. We run bioinformatics analyses on these clusters. Each analysis takes about 24 hours to complete, each core i7 server can handle 2 at a time, takes as ...
7
votes
2answers
308 views

Storage issues: Prolonging the life of a legacy Compaq ML370

I have an original ML370, from before there even were generations (2000). The storage system is comprised of a Smart Array 431 controller, 2 9.1 Gb Ultra3 SCSI (COMPAQ BD009635C3), and 4 146.8 Gb ...
7
votes
5answers
1k views

ML350 G5 - upgrade hot swap drives to 6 Gb/s?

I support a non profit. They got an ML350 G5 donated to them and I immediately put it to good use for them :) It came with four HP 300GB 15K SAS drives - and of course, they have all now failed. I ...
7
votes
1answer
13k views

KVM guest io is much slower than host io: is that normal?

I have a Qemu-KVM host system setup on CentOS 6.3. Four 1TB SATA HDDs working in Software RAID10. Guest CentOS 6.3 is installed on separate LVM. People say that they see guest performance almost equal ...
7
votes
3answers
358 views

Hard disk write-once mode on Windows

Is it possible to force a hard disk into 'write-once' mode in Windows? I want to securely store logs so they can't be changed, but I can't use tapes or optical media due to performance reasons.
7
votes
1answer
8k views

Why does “eager” vs “lazy” zeroing take much longer when provisioning a VM from a template?

Slightly related to a previous question about thick vs thin provisioning, why does eager zeroing the to-be-cloned VM take longer than lazy zeroing? For example, in a recent test we ran, an ...
7
votes
2answers
166 views

Array free space requirement

The general rule of thumb is don't use more than 80-85% of your capacity, otherwise performance degrades sharply, and other bad stuff may happen. On a 8TB array, this comes out to around 1.6TB of ...
7
votes
1answer
848 views

VMWare ESX and guest settings for Netapp cluster failover

If I'm running VMWare 5.x on FC [edit] LUNs presented from a Netapp running ontap 8.x in 7 mode, what steps should I take to ensure that the VMs can withstand a worst possible case cluster node ...
7
votes
1answer
553 views

IQN Naming convention

I've seen a lot of information about how IQN's should be formatted, but there's not a lot of information on how to build them. I'm kind of a newb when it comes to iSCSI, and i have it working, but I'm ...
7
votes
5answers
3k views

Block-level LUN replication options for Windows [closed]

When it comes to replicating a LUN or partition to a physically separate server, Linux has DRBD (now in the kernel!). As I understand it, it has both synchronous and asynchronous replication modes. ...
7
votes
8answers
810 views

How to store terabytes of large, randomly accessed files?

Lets say I have a couple of thousand large files (1-800mb each), that are all accessed at random, with newly uploaded files accessed very frequently, and as time passes, the access times drops off in ...
7
votes
1answer
245 views

Protecting Network attached storage

In your answers, please keep in mind that it is all about a home network. What is the best way of protecting a network attached storage from the outside world? Currently i have a NAS connected ...
7
votes
1answer
497 views

Which block sizes for millions of small files

I have 2x 4TB Disks in hardware RAID1 (it might be a LSI MegaRaid) on Debian Wheezy. The physical block size is 4kB. I'm going to store 150-200 million of small files (between 3 and 10kB). I'm not ...
7
votes
1answer
131 views

Disk size addressable by the OS

I have a 3ware 9550SXU-12 storage controller and 750G disks connected to it. The disks are configured as single units (not JBOD). I've been running some performance tests, mainly to see the impact of ...
6
votes
5answers
18k views

How do I get my HP servers to email me when a drive fails?

Ideally, with as simple of install as possible and without requiring rebooting the servers. Mostly for DL380 G5's if it helps. Thanks.
6
votes
8answers
2k views

What are SAS external storage options (Promise, Infortrend, SuperMircro, …)?

We are looking for a ~32T external storage solution for two 48-core AMD servers. These will be used for a small Linux OpenVZ cloud for CPU intensive web-servers and data warehousing. Dual path with ...
6
votes
2answers
616 views

Server Rack vs. Server in PC “Towers”

A friend of mine told me that the company he made an internship at didn't have server racks, because the cooling just takes up too much energy and thus isn't effective. That company was using "normal" ...
6
votes
3answers
650 views

With 200TB of needed storage, is a SAN a good idea?

My employer has, what I consider to be, a lot of data. We currently have about 10TB of data on our NAS, which is about its capacity, and we would have more data on it if we didn't constantly move ...
6
votes
4answers
242 views

Storage Architecture

Related to this question: When building a storage area network, do storage administrators generally create the physical disk arrays based on I/O type (sequential versus random access) and provision ...
6
votes
2answers
29k views

What is the fastest and safest RAID combination for SATA drives?

I wonder what is the fastest and safest RAID combination for SATA drives and general use (some write, mostly read)? RAID 0 is fast but utterly unsafe, RAID 1 is safe but slow, RAID 5 is safe but not ...
6
votes
5answers
844 views

LUNs and virtual machines

I have HP P2000 + XenServer solution working. What I'm thinking about is how to create LUNs for 20 virtual machines. Separate LUN for every VM ? It gives me ability to backup the specific virtual ...
6
votes
3answers
961 views

What are the typical methods used to scale up/out email storage servers?

What I've tried: I have two email storage architectures. Old and new. Old: courier-imapds on several (18+) 1TB-storage servers. If one of them show signs of running out of disk space, we migrate ...
6
votes
4answers
347 views

Is DAS OK for under-utilised virtual machines?

We're a little behind in the virtualization game, I'll have to admit. We currently have nothing virtualized, but I'm trying to change that. We want to get our feet wet with virtualization and get a ...
6
votes
3answers
1k views

Dell MD1000 and an x4 SAS connector throughput / layout

I'm trying to get my head around how a multi lane x4 SAS connector works in a DAS system such as the Dell MD1000. I understand that each lane is 3Gbps, and that multiple hard drives can share a lane. ...
6
votes
4answers
4k views

SAN or NAS 100-200TB - where to start looking? [closed]

I'm starting a project to consolidate a bunch of data and make it available on our LAN. I'm thinking that we may have a need for anywhere from 100-200TB at any one time. What factors should I be ...
6
votes
4answers
2k views

SAN system upgrade/design

Greetings, I'm a long-time lurker, first time poster. For brevity, let me ask my question up-front and then give the longer backstory, so you can choose how much you want to read. Short version... ...
6
votes
1answer
3k views

How to get checksum data integrity on ext4?

On file systems like btrfs you can preform a scrub, which will go though all the data to see if the data still matches the file system checksum. I would like to check the data on ext4 if it is ...
6
votes
3answers
1k views

Seeking distributed, fault-tolerant, networked block storage [closed]

I'm looking for a distributed, fault-tolerant network storage system which exposes block devices (not filesystems) on the clients. A client's block device should write simultaneously to several ...
6
votes
1answer
499 views

Completely disjoint iSCSI networks vs dedicated switches and VLANs

I'm looking for best practice or pros/cons for deploying an iSCSI storage network. The two options are: A completely disjoint iSCSI storage network Dedicated switches with a separate VLAN for ...
6
votes
4answers
367 views

What should I watch out for in building low-budget storage servers?

I'm looking to replace our current storage. The existing system is just a 450GB file share on our 7yr old domain controller, plus another 150GB from another server. We map these to drives on the ...
6
votes
4answers
219 views

Secure storage solution sought

I need an end-to-end multi-client/multi-supplier secure storage system, I can build it using various bits and pieces but it feels overcomplex - am I missing a trick? Specifically I need to offer ...
6
votes
2answers
4k views

Can I determine IOPS on a disk array using bonnie++?

I would like to measure the read and write performance of a RAID6 array verses a RAID10 array. I understand that bonnie++ can be used to calculate disk performance, but the numbers produced by ...
6
votes
3answers
2k views

Replicate a big, dense Windows volume over a WAN — too big for DFS-R

I've got a server with a LOT of small files -- many millions files, and over 1.5 TB of data. I need a decent backup strategy. Any filesystem-based backup takes too long -- just enumerating which ...
6
votes
1answer
853 views

Replace HP Smart Array E200i without losing data

I've got a Smart Array 200i which seems to have some bad slots (slot 3 and slot 5). It doesn't matter what HD I put in these slots, it keeps telling me the drive is bad. My question is two-fold: Is ...
6
votes
1answer
654 views

DFSR Backlog Stuck on Non-Existent Folders

I have two 2008r2 servers setup in a full-mesh multipurpose replication group. (01 and 02). 01 was the source server. The initial sync just finished last night and there are 2 folders that do not ...
6
votes
1answer
212 views

HP P9500 block level data integrity checking

Does the HP P9500 do any sort of block level data integrity checking on reads? If so, I'm looking for actual documentation that it does indeed do such a thing.
6
votes
1answer
392 views

DFSr detected that a file was changed on multiple servers, but “winning” file and that moved to conflicts folder have same hash

We've just deployed a new DFS replication system between two Windows 2012 R2 servers. We cloned the DFSr database using MS's recommendations ...
5
votes
3answers
16k views

Measure Linux IOPS for a running system

How do I measure IOPS of a running Linux server? I know that the theoretical IOPS of a SATA drive is around 90 and enterprise 10k SAS/FC disk is 180. I want to know how much my running system is using ...
5
votes
7answers
2k views

setup lowcost image storage server with 24x SSD array to get high IOPS?

I want to build let's name it a lowcost Ra*san which would host for our social site the images (many millions) we have 5 sizes of every photo with 3 KB, 7 KB, 15 KB, 25 KB and 80 KB per Image. My ...
5
votes
4answers
15k views

Pros and cons of installing ESXi on a SSD vs USB flash drive?

I'm debating on doing an ESXi 4.1/5.0 installation on a USB stick or a pair of 32GB SATA II SSDs (RAID1 mirror). According to VMWare's documentation, when ESXi is booting it looks for a 4GB space for ...
5
votes
4answers
14k views

Howto check disk I/O utilisation per process

Im having a problem with a stalling Linux system and I have found sysstat/sar to report huge peaks in disk I/O utilization, average service time as well as average wait time at the time of the system ...
5
votes
1answer
721 views

popular mass storage options

Can someone give me some examples of common mass storage devices people are using? Specifically, say you have front end servers that all need to connect to a mass storage device (SAN?), that provides ...