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

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7
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5answers
606 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
5answers
868 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
3answers
323 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
6k 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
143 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
655 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
278 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
2k 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
806 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
242 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
350 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
120 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
14k 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
529 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
326 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
5answers
814 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
884 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
337 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
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
4k views

mdadm and 4k sectors (advanced format)

There are numerous questions on Serverfault about aligning 4k sectors disks, but one thing is not really clear to me yet. I successfully aligned my RAID1+LVM. One of the things I did was use mdadm ...
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
462 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
362 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
216 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
3k 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
282 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
201 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
213 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
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
12k 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
7answers
5k views

Do you lose everything when you have a hard disk failure in a multi-hard disk LVM that does NOT use RAID?

I'm debating about using LVM for a media/file server because I would like to combine multiple physical hard disks into one volume. I do not wish to use any RAID in my LVM so my question is: If one ...
5
votes
4answers
10k 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
715 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 ...
5
votes
3answers
1k views

Open-source Shared Storage file system?

Can anyone advice for a production-level, open-source shared storage (SAN) file-system? I read about GFS and GFS2, but the first one seems a bit outdated, and the second is not considered stable for ...
5
votes
2answers
3k views

Does adding more drives to a RAID 10 Array increase performance?

I'd like to know if I were to add additional drives to an existing Raid 10 if this would increase the speed of the entire array?
5
votes
4answers
3k views

Does Windows Defrag utility reports fragmentation correctly on a RAID system?

We have a server with a RAID volume. Windows DEFRAG shows very high fragmentation (90%) on the volume. My chief asked if DEFRAG reported fragmentation is correct (or near correct) or not. We don't ...
5
votes
6answers
241 views

In a managed environment, should user PCs have local external HD backups?

Our environment manages thousands of user PCs, provides high-end secure file servers. Users (from new staff to executive-level) are urged to store data to the file servers and generally do so. PCs ...
5
votes
4answers
1k views

Do you use SSD in a production environment yet? [closed]

I'm not asking whether or not it's worth the money, as in Question 2425. I'm interested to see the level of acceptance in the production world up to now. Money can certainly relate to the answer, ...
5
votes
4answers
433 views

19" Rackmountable fast storage arrays

I'm in need of some fast (15+ GB/s write) and somewhat large (50 TB+) storage subsystem with a standard storage interface. I'd prefer something other than Fibre Channel, which admittedly appears to ...
5
votes
6answers
5k views

Is there a way to do something like LVM over NFS?

I realize that since NFS is not block-level, LVM can't be used directly. However: is there a way to combine multiple NFS exports (from, say, 3 servers) into one mount point on a different server? ...
5
votes
4answers
228 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 ...
5
votes
2answers
293 views

Networking with VMware, physical adapters and iSCSI

New VMware user here, setting up my first environment. I have an ESXi host that has four physical NiCs (NiC0, NiC1, NiC2, NiC3). I have installed ESXi, the VCVA appliance, and several VMs ...
5
votes
2answers
6k views

How do I change the size of a VHD?

I have a fixed size virtual hard drive that is running out of space. What's a good way to go about increasing the size? This VHD is created from Microsoft Virtual PC and/or Microsoft Virtual Server.
5
votes
3answers
784 views

Recommendations: configuring a 10GbE NAS stack for virtualisation storage

I'll try as hard as I can to word this so it is not considered a shopping list. We have been successfully running a dev/test ESXi environment for some time, with a couple of Dell PE2950III servers ...
5
votes
3answers
527 views

What is the ZFS ACL limit?

Does anyone know how many user ACL's ZFS can handle? With other words: for how many users can I set ACL's like this one for the same directory? setfacl -m user:test1:rwxpDdaARWcCos:fd----:allow ...
5
votes
1answer
9k 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 ...
5
votes
3answers
14k views

Is RAID 0 or JBOD better for home media server? [closed]

I have an external two-bay drive enclosure (the OWC Mercury Elite-AL Pro) connected to a Mac Mini (my home media server) over FireWire 800. I'm streaming media to other computers in the house over ...