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

learn more… | top users | synonyms (1)

32
votes
5answers
1k 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
votes
3answers
5k 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
2answers
3k 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 ...
26
votes
7answers
7k 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 ...
25
votes
1answer
4k views

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

How do FC switches work, and how should I configure mine?
24
votes
5answers
30k views

What is the difference between SAN, NAS and DAS?

What is the difference between SAN, NAS and DAS?
24
votes
3answers
18k 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 ...
23
votes
8answers
7k 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, ...
19
votes
4answers
1k 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 ...
15
votes
4answers
5k 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
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 ...
14
votes
12answers
9k 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 ...
14
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 ...
13
votes
3answers
2k 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 ...
13
votes
7answers
11k 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 ...
12
votes
1answer
203 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
9answers
17k 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 ...
11
votes
4answers
1k 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 ...
10
votes
10answers
3k 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
13k 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
1answer
753 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
3answers
29k 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 ...
9
votes
5answers
32k 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 ...
9
votes
6answers
34k 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 ...
8
votes
5answers
1k 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 ...
8
votes
3answers
904 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
7k 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
4answers
136 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 ...
8
votes
2answers
245 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
5answers
2k 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
6answers
2k 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 ...
8
votes
4answers
2k 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
27k 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
16answers
5k 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
7answers
1k views

What is a storage area network (SAN)? and What are some of the ways that it can be used? [closed]

I need some good examples and links to companies that you are already using for buying SAN hardware, SAN data centers, etc.,
7
votes
2answers
318 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?
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
2answers
296 views

iSCSI using uplink ports on switch

Do the uplink ports on switches typically work okay as iSCSI ports? We're adding a 10gb iSCSI SAN, and want to get a combo switch (48x1gb & 4x10gb SFP+ uplink ports) and use the 10gb for the iSCSI ...
7
votes
1answer
279 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
2answers
845 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 ...
7
votes
1answer
7k views

Windows 2008 Unknown Disks

I have a BL460c G7 blade server with OS Windows 2008 R2 SP1. This is a brand new C7000 enclosure, with FlexFabric interconnects. I got my FC switches setup and zoned properly to our Clariion CX4, ...
6
votes
5answers
569 views

Why do they use laptop form factor HDD's for storage servers?

The storage servers I've seen generally use 2.5" drives instead of 3.5" drives. In my experience the larger drives have better capacity, speed, and durability. Why are the smaller ones favored in ...
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
3answers
1k views

So what really makes a server grade NIC?

We have a couple servers hosting Citrix VM's. We are planning on adding SAN storage to our network so that we can do the quick migration and high availability thing. The question comes up with ...
6
votes
4answers
725 views

What would cause IO Wait on a SAN?

I understand IO wait when I see it on a server, it means that the CPU is blocked while I wait for the IO to catch up [source]. I am trying to understand why a SAN stats would show a high IO wait - ...
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
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
390 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 ...
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
2answers
693 views

links between switches for iSCSI

We inherited a SAN/vmWare/iSCSI setup with both Dell and HP equipment purchased for it, but not fully setup, and we need to get some additional switches to make it all work. But we're getting ...