Yes, looks good, Emphase makes good flash products. Also the SanDisk SSD U Series has a "capacitor system" to prevent data loss...
SanDisk - Unexpected Power Loss Protection - White Paper http://www.sandisk.com/assets/docs/unexpected_power_loss_protection_final.pdf I just placed an order for a "SanDisk U110 SDSA6GM-032G" for $45 USD to test. Lonnie On Oct 19, 2014, at 5:22 PM, Michael Knill <[email protected]> wrote: > This guy is not too bad! > > http://www.logicsupply.com/components/storage/msata-ssd/g5rm3g032-m/ > > Regards > Michael Knill > > > > > On 20 Oct 2014, at 9:01 am, Lonnie Abelbeck <[email protected]> wrote: > > I have read that SandForce controllers (now owned by Seagate) don't use DRAM > for caching... > "SandForce gave the name "DuraClass" to the overall technology incorporated > in its controllers. SandForce controllers do not use DRAM for caching which > reduces cost and complexity compared to most other SSD controllers. " > http://en.wikipedia.org/wiki/SandForce > > But I have not found anything smaller then 60 GB with a SandForce controller. > http://www.amazon.com/ADATA-SandForce-2-5-Inch-Solid-AS511S3-60GM-C/dp/B0050T28PQ/ > > Lonnie > > > On Oct 19, 2014, at 4:18 PM, Michael Knill > <[email protected]> wrote: > >> Whoops sorry. Just embarrassed myself again. Its dependent on the drive >> itself. >> >> Maybe we could have a list of known SSD drives that ‘do the correct thing’ >> >> Regards >> Michael Knill >> >> >> >> >> On 20 Oct 2014, at 8:13 am, Michael Knill >> <[email protected]> wrote: >> >> Hi thanks Lonnie >> >> Yes I would like to see something done and 1) & 2) are definitely out as >> being cost prohibitive. >> >> So what is the default flush time for the cache? >> If there are concerns about disabling it, couldn’t it just be changed to be >> very low? >> >> Regards >> Michael Knill >> >> >> >> >> On 19 Oct 2014, at 2:05 am, Lonnie Abelbeck <[email protected]> >> wrote: >> >> Hi, >> >> I'd like to start a discussion on the SATA Drive "write cache" and whether >> it should be disabled in AstLinux. >> >> In the past Compact Flash (CF) was the most commonly used AstLinux flash >> storage, but today some of the newer x86 hardware no longer support CF and >> are moving to mSATA and 2.5" SATA. >> >> I did a survey of my various boxes with SATA drives (2.5", mSATA and DOM) >> =========================== >> - Emphase D1VHSD001G0 (DOM) 2 GB SLC >> Write Cache: enabled >> >> - Emphase FD2510SI8G (2.5") 8 GB SLC >> Write Cache: disabled (not setable) >> >> - WDC SSD-M0004S-7100 (mSATA) 4 GB SLC >> Write Cache: enabled >> >> - ADATA SP600 (2.5") 32 GB MLC >> Write Cache: enabled >> =========================== >> >> And sure enough if I do a >> $ echo "Testing..." > /mnt/kd/test >> >> and pull the power plug, the /mnt/kd/test file does not exist on reboot. >> And before anyone asks :-) a journeled ext3 filesystem does not help here >> since the new "data" is only in the drive's volatile RAM. >> >> The "write cache" does increase write performance, and for a general >> computer, database, etc. this is desired. But, for the case of AstLinux I'm >> not sure if this extra performance gain is needed. >> >> There are a few solutions: >> >> 1) Use an Uninterruptible Power Supply (UPS). Personally I do this by using >> an inexpensive UPS supplying battery backup to the AstLinux box, cable modem >> and main ethernet switch. AstLinux monitors the UPS status. >> >> 2) Use SSD's that default to "Write Cache: disabled" (rarely found) or have >> a "Host Power Loss Protection" as with: >> http://www.logicsupply.com/components/storage/solid-state-drives-ssd/q6mp6g030-2/ >> >> 3) Set "Write Cache: disabled" at startup for such afflicted drives. >> >> Solutions 1 and 2 are self explanatory, so let's discuss 3... >> >> As far as I know, the "hdparm" command is the only way to disable the >> drive's write cache. I can't find a kernel driver option or kernel command >> line option to do that. >> >> AstLinux uses the Busybox version of hdparm, and as such the following code >> seems like a fairly safe way to disable the write cache: >> -- >> DRIVE="$(findfs LABEL=RUNNIX)" >> DRIVE="${DRIVE%[0-9]}" >> if [ -n "$DRIVE" ]; then >> if hdparm -I "$DRIVE" 2>/dev/null | grep -q -i >> '^[[:space:]]*[*][[:space:]]*write cache[[:space:]]*$'; then >> if hdparm -W0 "$DRIVE" >/dev/null; then >> echo "Disabled write cache for drive: $DRIVE" >> fi >> fi >> fi >> -- >> Now, using the hdparm command should not be taken lightly, and you might ask >> what happens to any active cache when the "hdparm -W0 ..." is issued, good >> question. Some possibilities are: >> >> 1) Do it early enough on boot before data writes occur. >> >> 2) Some SSD firmware will do the correct thing. >> >> 3) Try to flush any active cache. >> >> The Busybox version of hdparm has code to automatically flush the cache when >> a "hdparm -W0 ..." is issued, but is disabled in all versions of Busybox... >> -- >> #undef DO_FLUSHCACHE /* under construction: force cache flush on >> -W0 */ >> -- >> No doubt there is a general problem with doing this. >> >> So, what should we do in AstLinux ? If anything. >> All comments welcomed. >> >> Lonnie >> >> >> >> ------------------------------------------------------------------------------ >> Comprehensive Server Monitoring with Site24x7. >> Monitor 10 servers for $9/Month. >> Get alerted through email, SMS, voice calls or mobile push notifications. >> Take corrective actions from your mobile device. >> http://p.sf.net/sfu/Zoho >> _______________________________________________ >> Astlinux-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/astlinux-users >> >> Donations to support AstLinux are graciously accepted via PayPal to >> [email protected]. >> >> >> ------------------------------------------------------------------------------ >> Comprehensive Server Monitoring with Site24x7. >> Monitor 10 servers for $9/Month. >> Get alerted through email, SMS, voice calls or mobile push notifications. >> Take corrective actions from your mobile device. >> http://p.sf.net/sfu/Zoho >> _______________________________________________ >> Astlinux-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/astlinux-users >> >> Donations to support AstLinux are graciously accepted via PayPal to >> [email protected]. >> >> >> ------------------------------------------------------------------------------ >> Comprehensive Server Monitoring with Site24x7. >> Monitor 10 servers for $9/Month. >> Get alerted through email, SMS, voice calls or mobile push notifications. >> Take corrective actions from your mobile device. >> http://p.sf.net/sfu/Zoho >> _______________________________________________ >> Astlinux-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/astlinux-users >> >> Donations to support AstLinux are graciously accepted via PayPal to >> [email protected]. >> >> > > > ------------------------------------------------------------------------------ > Comprehensive Server Monitoring with Site24x7. > Monitor 10 servers for $9/Month. > Get alerted through email, SMS, voice calls or mobile push notifications. > Take corrective actions from your mobile device. > http://p.sf.net/sfu/Zoho > _______________________________________________ > Astlinux-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/astlinux-users > > Donations to support AstLinux are graciously accepted via PayPal to > [email protected]. > > > ------------------------------------------------------------------------------ > Comprehensive Server Monitoring with Site24x7. > Monitor 10 servers for $9/Month. > Get alerted through email, SMS, voice calls or mobile push notifications. > Take corrective actions from your mobile device. > http://p.sf.net/sfu/Zoho > _______________________________________________ > Astlinux-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/astlinux-users > > Donations to support AstLinux are graciously accepted via PayPal to > [email protected]. > > ------------------------------------------------------------------------------ Comprehensive Server Monitoring with Site24x7. Monitor 10 servers for $9/Month. Get alerted through email, SMS, voice calls or mobile push notifications. Take corrective actions from your mobile device. http://p.sf.net/sfu/Zoho _______________________________________________ Astlinux-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/astlinux-users Donations to support AstLinux are graciously accepted via PayPal to [email protected].
