search for: supercap

Now the test for the Vertex 2 Pro. This was fun. For more explanation please see the thread "Crucial RealSSD C300 and cache flush?" This time I made sure the device is attached via 3GBit SATA. This is also only a short test. I''ll retest after some weeks of usage. cache enabled, 32 buffers, 64k blocks linear write, random data: 96 MB/s linear read, random data: 206 MB/s linear

I recently got a new SSD (ocz vertex LE 50gb) It seems to work really well as a ZIL performance wise. My question is, how safe is it? I know it doesn''t have a supercap so lets'' say dataloss occurs....is it just dataloss or is it pool loss? also, does the fact that i have a UPS matter? the numbers i''m seeing are really nice....these are some nfs tar times before zil: real 2m21.498s user 0m5.756s sys 0m8.690s real 2m23.870s user 0m5.756...

Hi, I don''t know if it''s already been discussed here, but while thinking about using the OCZ Vertex 2 Pro SSD (which according to spec page has supercaps built in) as a shared slog and L2ARC device it stroke me that this might not be a such a good idea. Because this SSD is MLC based, write cycles are an issue here, though I can''t find any number in their spec. Why do I think it might be a bad idea: L2ARC is quite static in comparison with...

On Jun 28, 2019, at 8:46 AM, Blake Hudson <blake at ispn.net> wrote: > > Linux software RAID?has only decreased availability for me. This has been due to a combination of hardware and software issues that are are generally handled well by HW RAID controllers, but are often handled poorly or unpredictably by desktop oriented hardware and Linux software. Would you care to be more

Hello, Just a couple questions regarding RAID. Here's thesituation. I bought a 4TB drive before I upgraded from 6.8 to 7.3. I'm not too far into this that Ican't start over. I wanted disk space to backup 3 other machines. I way overestimated what I needed for full, incremental and image backups with UrBackup.I've used less than 1TB so far. I would like to add an additional drive

http://www.lsi.com/channel/about_channel/whatsnew/warpdrive_slp300/index.html Good stuff for ZFS. Fred -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20101117/d48186f0/attachment.html>

With all the recent discussion of SSD''s that lack suitable power-failure cache protection, surely there''s an opportunity for a separate modular solution? I know there used to be (years and years ago) small internal UPS''s that fit in a few 5.25" drive bays. They were designed to power the motherboard and peripherals, with the advantage of simplicity and efficiency

On Fri, September 8, 2017 12:56 pm, hw wrote: > Valeri Galtsev wrote: >> >> On Fri, September 8, 2017 9:48 am, hw wrote: >>> m.roth at 5-cent.us wrote: >>>> hw wrote: >>>>> Mark Haney wrote: >>>> <snip> >>>>>> BTRFS isn't going to impact I/O any more significantly than, say, >>>>>> XFS.

Hello, because of high disk load we plan to move from disk (raid1) to ssd. Are there recommendations for - manufacturer - file sytem - raid1 The Red Hat Storage Administration Guide says: - no raid 1 - ext4 only is this state of the art? I have searched list,centos.org 2015 - nothing found. I found in the year 2012 / 2013: https://www.centos.org/forums/viewtopic.php?t=7580

On 2/14/2017 4:48 PM, tdukes at palmettoshopper.com wrote: > 1- Better to go with a hardware RAID (mainboardsupported) or software? I would only use hardware raid if its a card with battery (or supercap+flash) backed writeback cache, such as a megaraid, areca, etc. otherwise I would use mdraid mirroring. > 2 - Can an existing drive with data on it be used as aRAID drive without > losing current data? software mdraid will let you add a mirror to an existing disk. or if its using LVM,...

...ear > manufacturers/models here. My choices would be: Areca or LSI (bought out > by Intel, so former LSI chipset and microcode/firmware) and as SSD Samsung > Evo SATA III. Does anyone who used these in hardware RAID can offer any > bad experience description? Does the Samsung EVO have supercaps and write-back buffer protection?? if not, it is in NO way suitable for reliable use in a raid/server environment. as far as raiding SSDs go, the ONLY raid I'd use with them is raid1 mirroring (or if more than 2, raid10 striped mirrors). And I'd probably do it with OS based software r...

...use of Microsoft Windows and VMware esxi, neither of which have good native storage management. Because of this, it's fairly hard to order a major brand (HP, Dell, etc) server without raid cards. Raid cards do have the performance boost of nonvolatile write back cache. Newer/better cards use supercap flash for this, so battery life is no longer an issue That said, make my Unix boxes zfs or mdraid+xfs on jbod for all the reasons previously given. >

On 14/02/17 07:58 PM, John R Pierce wrote: > On 2/14/2017 4:48 PM, tdukes at palmettoshopper.com wrote: >> 1- Better to go with a hardware RAID (mainboardsupported) or software? > > I would only use hardware raid if its a card with battery (or > supercap+flash) backed writeback cache, such as a megaraid, areca, etc. > otherwise I would use mdraid mirroring. > > >> 2 - Can an existing drive with data on it be used as aRAID drive without >> losing current data? > > software mdraid will let you add a mirror to an existin...

.... My choices would be: Areca or LSI (bought out >> by Intel, so former LSI chipset and microcode/firmware) and as SSD >> Samsung >> Evo SATA III. Does anyone who used these in hardware RAID can offer any >> bad experience description? > > > Does the Samsung EVO have supercaps and write-back buffer protection??? > if not, it is in NO way suitable for reliable use in a raid/server > environment. With all due respect, John, this is the same as hard drive cache is not backed up power wise for a case of power loss. And hard drives all lie about write operation comple...

Yes the flash-backed RAID cards use a super-capacitor to backup the flash cache. You have a choice of flash module sizes to include on the card. The card supports RAID modes as well as JBOD. I do not know if Gluster can make use of battery-backed flash-based Cache when the disks are presented by the RAID card in JBOD. The Hardware vendor asked "Do you know if Gluster makes use of

Preparing to build a small replacement server (initially built in 2005) and normally for the OS I would buy 2x500GB drives and deploy in a RAID 1 configuration. Now we have SSD drives available - does just a single SSD drive offer the same reliability or is there advantage in deploying two in a Raid 1 config? Also, what form factor / interface is best for the SSD OS boot device on a server

Your question is difficult to parse. Typically RAID and JBOD are mutually exclusive. By "flash-backed", do you mean a battery backup unit (BBU) on your RAID controller? On Mon, Apr 9, 2018 at 8:49 AM, Vincent Royer <vincent at epicenergy.ca> wrote: > >> Is a flash-backed Raid required for JBOD, and should it be 1gb, 2, or 4gb >> flash? >> > > Is anyone

On Sat, November 4, 2017 4:32 am, hw wrote: > Valeri Galtsev wrote: >> >> On Fri, November 3, 2017 3:36 am, hw wrote: >>> Valeri Galtsev wrote: >>>> If you have not Dell server hardware my choice of [hardware] RAID >>>> cards >>>> would be: >>>> >>>> Areca >>> >>> Areca is forbiddingly expensive.

The standard controller that has been recommended in the past is the AOC-SAT2-MV8 - an 8 port with a marvel chipset. There have been several mentions of LSI based controllers on the mailing lists and I''m wondering about them. One obvious difference is that the Marvel contoller is PCI-X and the LSI controllers are PCI-E. Supermicro have several LSI controllers. AOC-USASLP-L8i with the