45

First of all, for a (broad) comparison of DAS, NAS and SAN storage see here. There are some common misconceptions about the term "SAN", which means "Storage Area Network" and as such, strictly speaking, refers only to the communication infrastructure connecting storage devices (disk arrays, tape libraries, etc.) and storage users (servers). However, in ...


32

One of the servers that I administrate runs the type of configuration that you describe. It has six 1TB hard drives with a LUKS-encrypted RAIDZ pool on it. I also have two 3TB hard drives in a LUKS-encrypted ZFS mirror that are swapped out every week to be taken off-site. The server has been using this configuration for about three years, and I've never had ...


25

I generally use one of the following two filesystems: XFS for anything which does not play well with CoW (or for virtual machines whose datastore already is on a CoW filesystem) or when extremely fast direct I/O is required; ZFS for anything else. For your use case I would use ZFS, especially considering that Ubuntu 18.04 already ships it. As you can ...


18

I would like to improve the answer of this question as it was asked me many times. If your asking the differences between DAS- NAS -SAN you are in the data storage context; in this area many technologies exists which share a primary common goal: the persistence and availability of your data. Block devices and filesystems Most storage devices share the ...


13

BINGO!!! Alright, here is how this was resolved: I referenced this artice for unmounting the datastore, https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2004605 Step 1: Manually unmount the datastore from the host with this command: esxcli storage filesystem unmount [-u UUID | -l label | -p path ] In ...


11

S.M.A.R.T. can be used as an indicator that there are drive problems but can never be relied upon to indicate that a drive is good. When there is disagreement between multiple diagnostic systems always favour the one that shows the worst results.


10

What exactly are you talking about? Enterprise drives are typically SAS, and though SAS controllers can support SATA disks, SATA controllers cannot support SAS disks. If you got a SOHO NAS, then you probably cannot put SAS disks in it at all. If your NAS only supports SATA disks, you can't mix and match SAS/SATA at all. If your NAS does support SAS and SATA,...


9

I understand the desire to move away from pure block storage to something more flexible. However, I would avoid using a straight-up Linux storage stack for this when several storage appliance software offerings are available right now. A Linux approach could work, but the lack of management features/support, the XFS tuning needed (here and here) and the ...


9

rsync doesn't do SFTP. From the man page: There are two different ways for rsync to contact a remote system: using a remote-shell program as the transport (such as ssh or rsh) or contacting an rsync daemon directly via TCP. SFTP doesn't give you a shell, ergo it doesn't work for rsync. You'll need an SSH connection instead. Once you've ...


8

The first thing to think about is that if you run a file system and file sharing protocol on your storage device (making it a NAS), you won't have to run it on the server. That's a little bit of work avoided. If the file system will need to be shared among other servers and users, this might represent quite a bit of work avoided. If the server using the ...


8

Most NAS snapshots implement copy-on-write, so the snapshot itself initially takes up no space (or next-to-none, there is some overhead). But any block that is changed whilst the file it's part of is snapshotted must be copied. If an entire file is deleted whilst it's still in a snapshot, all those blocks must still be kept. So in your case above, as long ...


8

LACP always helps with redundancy but isn't your panacea for performance. https://thenetworkway.wordpress.com/2015/05/01/an-overview-of-link-aggregation-and-lacp/ TL;DR: You really need multiple TCP connections to get performance boost, and this isn't what's always possible... SMB can do that "automagically" so you either LACP or SMB Multichannel but say ...


8

The NAS is a 2U Synology Rack set up in SMB 2.0 and higher mode. Plenty of space on the share (and NAS). The server is Windows 2012 R2 SMB 2.xx is your problem. You need SMB 3.xx to allow Hyper-V running VMs from your file share. https://blogs.technet.microsoft.com/yungchou/2012/09/10/windows-server-2012-hyper-v-over-smb-explained/


8

Nowadays the border between NAS and SAN is unclear especially for SMB products. Historically NAS devices consist of the bunch of disks arranged in some RAID to maximize the overall performance and achieve the required data redundancy. These devices have core operating systems aboard. Those OS do all low-level processing and file systems maintenance. File ...


7

The advantage comes when you're supporting solutions that may not work well with block storage, or if cost of proper FC infrastructure is prohibitive. Think of a large distributed application in a high-performance computing environment. Let's say 1,000 compute nodes. NFS may be ideal for application data because its per-port cost is low, it scales and is ...


7

Why on earth would you want to replace wired Ethernet with wireless? Especially if the wiring is already in the walls! Wireless should be a supplement to the business, not the only means of connectivity. The rest of your question is unanswerable. How can I possibly know if one AP will cover your whole office without going there to do a site survey? Sure ...


7

WDC Green drives have the "deep recovery" problem. You'll need Red or RE drives to avoid it. I have a ZFS RAIDZ of Green drives at home. They've lasted almost 3 years of Power On Hours without a single error. This may be just lucky, but errors don't generally happen all that often. So you have to ask, is the cost difference worth it. Take the value of up-...


7

NET USE does not allow you to connect to the same server with different credentials. This is because it reuses the same relationship to map additional shares on the same server. You can work around this by making windows think it's a different server either by creating DNS aliases for the same NAS with different names or editing the hosts file on the clients....


7

We are using Veeam generally over the whole company's infrastructure and it works great for a years. AFAIR you can even use free version. https://www.veeam.com/free-virtualization-software-vmware-hyper-v.html


7

SAN/NAS for < $3,600 per TB? This is totally doable. However, don't forget that apart from SAN hardware/software itself, there are lots of things that should be considered, such as: redundant power supplies, redundant WAN/LAN, IT staff onsite who will manage your infrastructure, etc.. First off, define how much downtime costs for you company and ...


6

You could reword this as a non-shopping question, "How do I hook up a dozen SATA drives without using port multipliers or multiple PCI cards?" so I'll write an answer to that magical question: Buy a multi-ported SAS card and associated SAS 4x breakout cable (SFF-8087 MiniSAS to 4 SATA). 6gbps SAS2 is like SATA3 (6Gbps). Then use whatever motherboard you ...


6

Definitely agree with both answers already provided here. If head office is running on a single host you should probably get a second one regardless of storage latency - phoebus Nov 1 '13 at 12:17 My understanding is that average latency for a VMFS datastore should be 20ms or less, so I don't see a problem here. – joeqwerty Nov 1 '13 at 15:12 I would dig ...


6

Yes, it's still the convention, and yes, it holds true even as you scale. With ZFS, in fact, you really don't want to get to the 75% mark in your zpool too often. Fragmentation, snapshots and general performance tend to be impacted. If building anew, don't start with anything more than 40% utilization and be sure to plan for growth.


6

This tip worked for me in the past, if you can disable ATS-Only: Cannot mount the VMFS5 datastore when using storage encryption appliances (2030416) I guess no VM are up in your case, but they need to be close to be able to run the command. Some storage encryption appliances may block certain SCSI commands, including ATS commands, sent from ESXi ...


6

I have reproduced this scenario in my test environment and I could find my data normally. To reproduce it I've followed these steps. Make sure that you follow every steps. Editing this file needs root access; therefore you will need to use sudo with your command. You can also open the file in any of your personal favorite text editors. 1 - Installed and ...


6

They use MDRAID+LVM and they use their proprietary software RAID implementation. Second one should be avoided due to smaller user base and recovery issues. https://www.synology.com/en-us/knowledgebase/DSM/tutorial/Storage/What_is_Synology_Hybrid_RAID_SHR


5

The thing to remember about WiFi is that the maximum throughput with n is about 144Mbps. Compare this to your wired connection which is most likely running 1Gbps. Now, add to this the fact that WiFi is a shared medium meaning all wireless clients associated to a single AP are sharing that 144Mbps. Wired connections will provide significantly greater ...


5

There's no point in re-inventing the wheel. I know that Synology and QNAP use mdadm (all bets are off with Netgear hardware). It's a tried and true solution, and in a NAS a huge cost saving and performance is OK. Given that new file systems like ZFS basically make hardware-level raid redundant, this is an OK thing. The only time when it's not so great is ...


5

Just because you can hot-swap a disk doesn't mean you should. The backplane and connectors aren't likely designed for large numbers of insertions / removals and the mechanical stress alone is probably going to create reliability problems for you. That alone would dissuade me from doing what you're trying to do. Having only two or three generations of ...


5

Storage latency will be your metric. If your application is highly sensitive to storage latency you'll want to steer clear of AWS and go physical, or drop the money to get the Storage Optimized instances. They specifically state those are the types for things like Hadoop and Cassandra. The thing about the higher tiers of AWS instance types is that it isn't ...


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