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Questions tagged [storage-area-network]

A SAN is a Storage Area Network, for providing block-level access to storage subsystems across a network.

66
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5answers
135k views

What is the difference between SAN, NAS and DAS?

What is the difference between SAN, NAS and DAS?
35
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2answers
7k views

What is a Storage Area Network, and which benefits does it have over different storage solutions?

I'm proposing this to be a canonical question about enterprise-level Storage Area Networks. What is a Storage Area Network (SAN), and how does it work? How is it different from a Network Attached ...
35
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5answers
2k views

Pay no attention to that SAN behind the curtain

Once upon a time, I built my own SQL servers, and had control over drive configuration, RAID levels, etc. The traditional advice of separation of data, logs, tempdb, backups, (depending on budget!) ...
29
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3answers
10k views

Tuning iSCSI storage

This is a Canonical Question about iSCSI we can use as a reference. iSCSI is a protocol that puts SCSI commands as payload into TCP network packets. As such, it is subject to a different set of ...
28
votes
4answers
33k views

Testing whether jumbo frames are actually working

Is there a command to test whether jumbo frames are actually working? i.e. some sort of "ping" that reports whether or not the packet was broken up along the way. I've an ESXi host with an Ubuntu VM ...
27
votes
7answers
8k views

SQL Server disk design on an ISCSI SAN

Its standard practice to separate log and data files to separate disks away from the OS (tempdb, backups and swap file also) Does this logic still make sense when your drives are all SAN based and ...
27
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1answer
12k views

How should I set up my Fibre Channel (FC) network?

How do FC switches work, and how should I configure mine?
27
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9answers
14k views

What kind of storage do people actually use for VMware ESX servers?

VMware and many network evangelists try to tell you that sophisticated (=expensive) fiber SANs are the "only" storage option for VMware ESX and ESXi servers. Well, yes, of course. Using a SAN is fast, ...
25
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15answers
20k views

Cheapest iSCSI SAN for Windows 2008/SQL Server clustering?

Are there any production-quality iSCSI SANs suitable for use with Windows Server 2008/SQL Server for failover clustering? So far, I've only seen Dell's MD3000i, and HP's MSA 2000 (2012i), which both ...
21
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4answers
2k views

Why would a heavily disk intensive application run faster on a SAN than on a Physical Disk?

Why would a heavily disk intensive application run faster on a SAN than on a Physical Disk? I would have expected the Physical disk to be slightly faster but in fact the process ran 100 times faster ...
18
votes
3answers
3k views

150 TB and growing, but how to grow?

My group currently has two largish storage servers, both NAS running debian linux. The first is an all-in-one 24-disk (SATA) server that is several years old. We have two hardware RAIDS set up on it ...
17
votes
5answers
3k views

Best Practices for virtualizing servers onto the SAN?

Alright, so I want to start leveraging my SAN a little more than I have been, and at the same time, take advantage of ESXi. Currently, I've got an array of Dell PowerEdge 1955 blades connected to a ...
16
votes
5answers
8k views

ZFS and SAN — best practices?

Most discussions of ZFS suggest that the hardware RAID be turned off and that ZFS should directly talk to the disks and manage the RAID on the host (instead of the RAID controller). This makes sense ...
15
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12answers
11k views

Are there no downsides to NetApp SAN solutions other than price? [closed]

We have pretty much decided on a NetApp solution for our first SAN. Given that, I've been tasked with finding as much reason not to go with NetApp as I can. We like to do this A) so we know what we're ...
15
votes
5answers
1k views

Choosing a SAN technology for 100s of VM Web Servers

The Problem We have an issue with performance on an existing platform, so I'm turning to the hive mind for a second opinion on this. The performance issue so far relates to IOPS rather than ...
15
votes
5answers
959 views

Is my new Oracle DBA talking sense

When we setup FC LUNs for our MSSQL boxes we rarely have to present them with more than about 8 distinct LUNs of various kinds (Quorum, MSDTC, TempDB, Data, Logs, Backup and a few others). We have a ...
15
votes
2answers
338 views

How to get free space from mounted drive Redhat 7

In our VM infrastructure, we have clustered hosts going to a SAN. What i am trying to figure out is how much "white space" is left over when deleting files within our Redhat servers. On our Windows ...
14
votes
9answers
40k views

How many disks is too many in this RAID 5 configuration?

HP 2012i SAN, 7 disks in RAID 5 with 1 hot spare, took several days to expand the volume from 5 to 7 300GB SAS drives. Looking for suggestions about when and how I would determine that having 2 ...
14
votes
3answers
47k views

SAS vs. Nearline/MDL SAS - What is the difference?

As subject I guess, looking at SAN's and most vendors offer 10k or 15k "proper" SAS drives, many also offer 7.2k MDL/Nearline SAS drives. Does anyone have an authoritative explanation of the ...
14
votes
4answers
51k views

Best practice for assigning private IP ranges?

Is it common practice to use certain private IP address ranges for certain purposes? I'm starting to look into setting up virtualization systems and storage servers. Each system has two NICs, one ...
14
votes
7answers
16k views

SQL Server Files Local or NAS or SAN?

I have to install a new Server with SQL Server 2008, What do you recommend, One server with Raid 10 or the Files in a NAS? What about iSCSI should I use it? What about SAN? The server has 4Gb of ...
13
votes
5answers
71k views

SSH / SCP Server on Windows [duplicate]

Possible Duplicate: What is a good SSH server to use on Windows? Can anyone on the SF community recommend a trustworthy/easy to set up SCP server for windows. I do not want to go through the ...
12
votes
1answer
450 views

What's the point of SAN routing?

I'm familiar with extending fabrics by adding more switches to it, but i don't get why sometimes it's better to do routing between fabrics (considering all the switches are from the same vendor, using ...
11
votes
4answers
7k views

Disk Speed Performance in a SAN

We are currently looking into buying a SAN, and have some concerns over the speed of disks we are going to put into the array. We would normally have gone for 15k disks over 10k every time, but one of ...
11
votes
6answers
18k views

How do you backup a SAN?

long time reader, first time asker :) I have been reading up a lot on iSCSI and SANs in general and I believe I have been able to answer most of my questions and concerns on the topic, but this one ...
10
votes
10answers
4k views

Cost effective and frugal SAN solution for under $5000?

I will have 3-4 servers that will need SAN access for both IOPS performance, and raw storage capacity. The limit is, cost. Solutions I have seen run $10,000+ for anything 9TB or higher. If I were to ...
10
votes
6answers
52k views

VMware VMFS5 and LUN sizing - multiple smaller datastores, or 1 big datastore?

With VMFS5 no longer having the 2TB limit for a VMFS volume, I'm considering which scenario would be more beneficial overall:- Less LUNs of larger size, or More LUNs of smaller size. In my case, I ...
10
votes
1answer
921 views

Correct placement of devices on a Fibre Channel fabric

We're getting a pair of new 8Gb switches for our fibre channel fabric. This is a Good Thing since we're running out of ports in our primary datacenter, and it'll allow us to have at least one 8Gb ISL ...
9
votes
5answers
2k views

Is brand-name NAS overpriced?

NetGear's ReadyNAS 2100 has 4 disk slots and costs $2000 with no disks. That seems a bit too expensive for just 4 disk slots. Dell has good network storage solutions too. PowerVault NX3000 has 6 disk ...
9
votes
2answers
4k views

Can you connect a SAN directly to a HBA with Fibre Channel?

I am in the process of sourcing our company's first SAN as we have the need for high availability/shared storage. I have noticed fibre channel switches are extremely expensive, and for redundancy we ...
9
votes
4answers
5k views

SAN with a few SSD drives, or lots of old fashioned HDDs?

My company is trying to figure out what type of SAN to purchase. This is specifically for database servers that are becoming IO constrained (storage is DAS right now, but we're hitting the limit of a ...
9
votes
4answers
1k views

ZFS stripe on top of hardware RAID 6. What could possibly go wrong?

I have 36*4TB HDD SAN Rack. RAID controller did not support RAID60 and not more than 16 HDDs in one RAID group. So I decided to make 2 RAID6 groups of 16HDD or 4 of 8 HDDs. I want to get all storage ...
9
votes
1answer
1k views

Why MPIO instead of 802.3ad Team for iSCSI

Doing my first server to iSCSI target and I thought i would be off to a running start by teaming my NIC on the server (conventional 802.3ad team). However, from many online sources I see this is NOT ...
9
votes
1answer
220 views

Mixing HBAs in a failover cluster?

I have a two server failover cluster, and for various reasons - they're on mismatched hardware. One has Emulex HBAs installed, the other Qlogic. I'd be twitchy about using two different makes/...
9
votes
5answers
4k views

Is there a Distributed SAN/Storage System out there? [closed]

Like many other places, we ask our users not to save files to their local machines. Instead, we encourage that they be put on a file server so that others (with appropriate permissions) can use them ...
8
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 ...
8
votes
3answers
7k views

Why should iscsi traffic be isolated?

Why should iscsi SAN traffic be isolated? I'm trying to explain to my network guy why we should isolate the traffic.
8
votes
3answers
10k views

Setup of HP ProCurve 2810-24G for iSCSI?

I have a pair of ProCurve 2810-24G that I will use with a Dell Equallogic SAN and Vmware ESXi. Since ESXi does MPIO, I am a little uncertain on the configuration for links between the switches. Is a ...
8
votes
2answers
350 views

What is “deduplication”?

I mean, I can look up the dictionary definition, but why is everyone suddenly talking about it in reference to virtual tape libraries? What's "new" here so that it's so much in the news lately?
8
votes
2answers
735 views

“Mandatory” free space on a SAN?

I'm not an expert of SANs, I'm writing here to get some clues on continuous and exasperating problems we're having which our supplier seems not to be able to solve. we own an ENHANCE ES3160P4 SAN ...
8
votes
2answers
309 views

Can i pause VM's while power-cycling iscsi storage array

Unfortunately I may have to power-cycle my storage array. In the context of using KVM with libvirt managing the Virtual Machines where i need to power-cycle the storage array, is it possible or even ...
8
votes
1answer
600 views

Using non-certified hard drives in Dell MD3220 storage array

Is it possible to use non-certified hard drives in a Dell MD3220 storage array? I ended up getting 3 new drives that were the EXACT same model number as the existing ones. Then I bought the drive ...
8
votes
2answers
452 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 ...
8
votes
6answers
47k views

Windows share: The specified network name is no longer available

We've got an EMC NX4 SAN box serving a CIFS share to a number of Windows Server 2008 R2 app servers. The app servers are using the CIFS share to serve lots of image files (~2500 ops/sec on the share), ...
8
votes
6answers
3k views

What are the most important aspects to consider when choosing a SAN for a small office virtualization project?

I am in the process of consolidating 6 physical servers running 6 different operating system flavors (don't ask) into two identical physical servers (Dell PowerEdge 2900), using the free VMware ESXi 4....
8
votes
1answer
5k 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 ...
8
votes
4answers
3k views

What Makes Cloud Storage (Amazon AWS, Microsoft Azure, google Apps) different from Traditional Data center storage networking (SAN and NAS)?

Some confusion because of my question so to make it simple : "What kind of storage do big cloud providers use and why?" As far as i understand, however I am not able to find any kind of official ...
8
votes
2answers
3k views

How Fibre Channel Frames are populated and traverse a Fabric?

Trying to wrap my head around how Fibre Channel Frames are actually populated and sent through a switched fabric. I Understand WWNN WWPN, WWNN is a WWN of the actual HBA, and WWPN are the WWN of the ...
8
votes
2answers
41k 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
3answers
13k views

How can I use NTFS and iSCSI and not corrupt my SAN?

I know you can't use multiples NTFS machines/servers with the same SAN iSCSI target without corruption. I have multiple servers, however, that need access to the same data on the same SAN. I do not ...