85

You are confusing your units. M = mega m = milli B = byte b = bit When referring to disk usage, we measure throughput in megabytes per second, or MB/s. Notice the capital M for mega and the capital B for bytes. When referring to network performance, we measure throughput in megabits per second, or Mb/s. Notice the lowercase b. A bit is eight times ...


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 ...


23

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 ...


15

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 ...


12

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.


12

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 ...


10

My current recommendation is NexentaStor, available in a free community-supported edition and as a commercial offering. Also see: Anybody have experience with using Nexenta? NexentaStor CE or Openfiler? Which do you recommend?


10

FreeBSD 8.2, running ZFS. ZFS includes the following out of the box: Supports NFS & iSCSI out of the box. ZFS includes Snapshots, data checksums, multiple copies, filesystem compression RAID-Z - Similar to RAID-5, but without the RAID-5 write hole. All disk writes are atomic copy-on-write transactions, so the on-disk state is never inconsistent (No ...


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 concur with the NexentaStor suggestion, but since I work for Nexenta I suppose that's expected. Bear in mind no matter whom you go with, big storage (which 200 TB would qualify as, if on the low end) really requires some grasp of your use-case(s) and a discussion with a qualified storage engineer if you don't want to end up with something that is at best ...


9

I would highly advise against using a NAS for anything else than a file server. The only way you can tell if it would cope is by actually doing it - but I would reccomend a dedicated machine for this. The HP ProLiant MicroServer could be a choice, same price range currently, and comes with a dual-core 1.5Ghz CPU, 2GB RAM and a 250GB HDD.


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 ...


8

Sure - but it can only be done with the VM running of you have licensing that allows for Storage VMotion. Otherwise, you'll shut the VM down and unregister it ("remove from inventory"), then in the datastore browser select the VM's directory and select the "move" option (the little paper with an arrow) in the top panel. Once that completes, find the VM in ...


8

Ok, first - Tape is more reliable than (disc) drives. Mostly / also because with a drive the drive is on the medium, with a tape you can use another drive to read a tape. Tapes also store huge amounts of data for a relatively low price - they are the most efficient form for offline backup (no real time single file restore) and often used in combination with ...


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

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

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/


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

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

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-...


6

Instead of a single boot disk and 3 disks in RAID 5, consider 4 disks in RAID 10. This is both faster and safer. You do not want your NAS to go down if the single boot disk fails. Additionally, RAID 5 has poor write performance and does not rebuild reliably on large, terabyte-denominated volumes, especially when you are using inexpensive drives. Answers: ...


6

What you propose is perfectly fine. NAS is double the cost for half the performance (my gross simplification of our evaluation). You could even build your own NAS with a Linux box and some open source software. Ultimately though, for 4 VMs on a single processor virtual setup, you are golden with what you proposed - we ran such a setup for a long time ...


6

"Bitmap" is used to allow faster RAID rebuild times, but you will be able to recover without it if you have a proper RAID level enabled.


6

Get "cheap" 2.5" SATA drives, they work in SAS enclosures. If you're using a Pxxx series controller (the norm in HP servers) it might not work with just any drives, and is guaranteed to not run at optimum (HP uses custom firmware on their drives to get the most out of them). I really could not recommend one particular drive over another, though I've had good ...


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

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....


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 ...


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.


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