Hi, > Op 10 september 2017 om 8:37 schreef Ivan Kudryavtsev > <kudryavtsev...@bw-sw.com>: > > > Hello, community. > > During the last years Linux kernel got some interesting features like KSM, > ZSWAP, ZRAM. Hardware also steps forward and we see Intel 3d xpoint, > extremely fast SSD drives with m.2 and PCI-E interfaces. > > These facilities enable potentially interesting use of overcommited RAM for > hosts. According to IBM's investigations Zswap with LZ4/ZBUD increases > virtual RAM on 40%. > > I investigated current Apache CloudStack memory overcommitment capabilities > and they mostly affect VM's RAM by utilizing ballooning and I think it's > not what necessary to open new facilities. There are many cases which can > utilize ZSWAP and fast swap devices to efficiently provision more RAM than > presents. > > I suppose, CloudStack Agent for KVM can have configured parameter which > "mangles" RAM reported. From the other hand it can be done by implemented > host properties on server side. I tried manual increasing in host table: > > update host set ram=ram * 1.4 where id=1; > > and it seems until the next host stats update it works as expected. I think > this workaround is useful, but it's better to have the function in core > like standard. >
Can't you set memory over provisioning on a cluster basis in the GUI? I thought you could. Wido > Let me know what you think about it, it might be I don't understand > something and ACS already has it in place? I also would like to hear your > thoughts on ZSWAP usage in practice. > > -- > With best regards, Ivan Kudryavtsev > Bitworks Software, Ltd. > Cell: +7-923-414-1515 > WWW: http://bitworks.software/ <http://bw-sw.com/>
